Coagulase-negative Staphylococci Research Articles

Shifting trends in bloodstream infection-causing microorganisms and their clinical impact in patients with haematologic malignancies in South Korea: A propensity score-matched study

BackgroundThis study aimed to identify recent trends in the epidemiology of bloodstream infection (BSI)-causing microorganisms among patients with haematologic malignancies (HMs) between 2011 and 2021, and to determine their impact on patient outcomes. MethodsThis retrospective study included 6792 patients with HMs, of whom 1308 (19.3%) developed BSI within 1 y of diagnosis. The incidence of BSI-causing microorganisms was determined, and a propensity score-matched study was performed to identify risk factors for 28-d all-cause mortality in patients with HM. ResultsA total of 6792 patients with HMs were enrolled. The cumulative incidence of BSI and neutropenia was significantly higher in the acute myeloid leukaemia and acute lymphoblastic leukaemia groups compared to other groups, and neutropenia and type of HMs were risk factors for the development of BSI. The annual incidence of coagulase-negative staphylococci (CoNS)-BSI decreased significantly (P < 0.001), whereas Klebsiella pneumoniae-BSI increased (P = 0.01). Carbapenem nonsusceptibility rates in K. pneumoniae isolates increased from 0.0% to 76.5% (P < 0.001). BSI caused by K. pneumoniae (adjusted odds ratio 2.17; 95% confidence interval 1.12–4.21) was associated with higher 28-d all-cause mortality compared to that caused by CoNS (adjusted odds ratio 0.86; 95% confidence interval 0.48–1.55). ConclusionThe pathogenic spectrum of BSI-causing bacteria in patients with HMs gradually shifted from Gram-positive to Gram-negative, especially from CoNS to K. pneumoniae. Considering that K. pneumoniae-BSI had a significantly higher 28-d mortality rate than CoNS-BSI, this evolving trend could adversely impact the clinical outcomes of patients with HMs.

#1438 Review of the use of peritoneal catheter sealing in peritonitis

Abstract Background and Aims Relapsing peritonitis is a new episode of peritonitis caused by the same microorganism occurring less than 4 weeks after the end of treatment of the previous one. It is associated with the formation of biofilm formation in the lumen of the peritoneal catheter and may lead to its removal. It is associated with increased technique failure, morbidity and mortality and health care costs. The aim of this study is to demonstrate the efficacy of peritoneal catheter sealing with taurolidine-heparin (T-H) in the prevention of relapsing peritonitis and thus avoid more aggressive measures in these cases, such as catheter removal. Method We performed a single-center retrospective analysis study. We analyzed episodes of peritonitis in our peritoneal dialysis (PD) unit over a 5-year period from January 1st 2019 to December 31st 2023. We collected demographic data and risk factors during this period: age, sex, CKD etiology, diabetes, modality, assisted PD, and S. aureus nasal carrier status. We documented peritonitis during the period, causative germs, treatment performed, and catheter sealing. We documented sealing patterns and evolution (cure, recurrence, catheter removal). We performed T-H sealing with a full abdomen and once the treatment had been completed. The catheter sealing with antibiotics was performed right after the intraperitoneal antibiotics’ doses during the treatment. Results We analyzed a total of 84 patients. Demographic characteristics were: mean age 66.5 years (range 24-88 years), 71.4% male, 28.6% diabetic, 45.2% on APD, 11.9% assisted PD, 5.9% nasal S. aureus carriers. Etiology of CKD: 66.7% unaffiliated etiology, 11.9% glomerulonephritis, 7.1% ADPKD, 5.9% chronic tubulo-interstitial nephritis and 1.2% vasculitis, multiple myeloma, anephritis, acute tubular necrosis, lupus, Alport syndrome and nephronophthisis. There were 71 episodes of peritonitis, in 32 patients. The causative germs were: 36.6% coagulase negative staphylococci, 21.1% streptococci, 19.7% negative culture, 7% enterobacteria, 7% polymicrobial, 4.2% S. aureus, 2.8% enterococci and 1.4% corynebacteria. We performed some type of sealing in 47 peritonitis cases: 34% with antibiotic alone, 21.3% with antibiotic plus T-H and 44.6% with T-H alone. A total of 55.3% of the sealings were performed in peritonitis caused by coagulase-negative staphylococci, 65.4% of which were sealed with T-H or antibiotic plus T-H (Table 1). Two of the peritonitis relapsed with conventional treatment (unsealed or sealed with antibiotic) and, after sealing the peritoneal catheter with T-H, no recurrence was observed. The catheter was removed from a patient with peritonitis plus S. aureus tunnelitis, a new catheter was placed deferred, but he had a new episode of peritonitis with S. aureus tunnelitis and the catheter was removed again; this patient's case is special as he has not maintained adequate hygiene measures in addition to lack of adherence to therapy. Conclusion Peritoneal catheter sealing, especially with T-H, appears to be effective in the treatment and prevention of relapsing peritonitis. In our case, we did not observe any recurrent peritonitis after its use. Despite its widespread use, there are hardly any studies on its use and the most recommendable guidelines for its use, which is why we believe that further studies should be conducted to establish guidelines and methods for its use.

#2276 Blood stream infections in patients with ANCA-associated vasculitis—a Danish nationwide study

Abstract Background and Aims Infection due to the immunosuppressive treatment, is among the most frequent causes of hospitalization and death in patients with ANCA-associated vasculitis (AAV). Information on prevailing causal microbial aetiologies is crucial for improving treatment and prevention of such events. Here we examined causal bacteriology, incidence, and risk of blood stream infections (BSIs) in incident and prevalent AAV patients, as compared to the general population. Method All data were retrieved from the Danish nationwide registries and the Danish Microbiology Database. Prevalent patients between 1998-2010 were all included at the same index date 1.1.2010; Incident patients diagnosed after 2010 were included with index being the day of diagnosis. Both groups were followed until first time BSI, death, or a maximum of 12 months. Background controls were matched 1:4 on age and sex. Cumulative incidence was assessed by the Aalen-Johansen estimator, and cox analyses adjusted for age, sex, kidney involvement, hypertension, diabetes, dialysis, and plasma exchange (PLEX), were used to model survival time. Results A total 19 (2.3%) BSIs were identified in 818 prevalent patients, and 55 (5.9%) BSIs in 939 incident patients (P &amp;lt; 0.001). As in the background control group, primary causal microbial agents among prevalent patients were E. coli (26.3%) and S. aureus (21.1%), with an overall Gram-negative predominance (58.8%). E. coli (17.5%) remained the most frequent microbial cause of BSIs in incident patients, however with a relatively higher frequency of gram-positive bacteria (50.9%) dominated by Coagulase-negative Staphylococci (12.3%), Enterococci (14%), and Streptococci (14%). Difference in bacteriology between prevalent and incident patients disappeared when patients on dialysis were excluded, whereas the difference in BSI frequency remained significant (p &amp;lt; 0.001). One-year HR of first-time BSI was significantly higher in patients with AAV as compared to controls (prevalent AAV: HR 3.17 [95% CI 1.63-6.18], p &amp;lt; 0.0001; Incident AAV; HR 8.64 [95% CI 4.88-15.31], p &amp;lt; 0.0001), with significant difference between incident and prevalent patients (HR 2.73 [95% CI 1.39-5.35], p = 0.003). Dialysis (HR 3.15 [95% CI 1.86-5.31], p &amp;lt; 0.0001) and PLEX (HR 1.87 [95% CI 1.05-3.33], p &amp;lt; 0.033) were solitary risk factors of BSI as well as higher age, hypertension, diabetes, and kidney disease (Figure). Risk of BSI remained significantly increased for both prevalent and incident patients as compared to matched background controls when patients on dialysis were excluded. Conclusion E. coli and S. aureus were predominant causal isolates in prevalent AAV patients and controls, and the gram-positive predominance seen with incident AAV was primarily caused by patients on dialysis. Risk of BSI was higher in incident AAV as compared to prevalent AAV, and the AAV diagnosis was associated with increased risk of BSI at all times, with highest risk initially after first diagnosis. Interventions requiring a central venous catheter were solitary risk factors of BSI.

Analysis of long-term dynamics of antibiotic sensitivity of coagulase-negative staphylococci isolated from surgical hospital patients at various times

Objective. To carry out twenty-year analysis of dynamics of antibiotic sensitivity of coagulase-negative staphylococcal strains isolated from surgical hospital patients. Materials and methods. The antibiotic sensitivity of 191 strains of coagulase-negative staphylococci isolated in 2004, 2014, 2023 year from surgical hospital patients was studied with the disk diffusion method. Results. A significant increase in the proportion of strains resistant to all antibiotics known, especially ciprofloxacin, was found. Сonclusion. A twenty-year analysis of the dynamics of antibiotic sensitivity showed a significant increase of antibiotic resistance of coagulase-negative staphylococcus strains isolated from surgical patients.

Assessment of handwashing impact on detection of SARS-CoV-2, Staphylococcus aureus, Escherichia coli on hands in rural and urban settings of Côte d'Ivoire during COVID-19 pandemic.

Handwashing is the first line of hygiene measures and one of the oldest methods of preventing the spread of infectious diseases. Despite its efficacy in the health system, handwashing is often inadequately practiced by populations. This study aimed to assess the presence of SARS-CoV-2, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) on hands as indicators of lack of hand hygiene during COVID 19 pandemic. A cross-sectional study was conducted in rural Taabo and urban Abidjan (Côte d'Ivoire) from January to September 2021. A total of 384 participants from 384 households were included in the study. The total households were distributed proportionally within various municipalities in the two study areas according to the number of households in each municipality, based on data of the National Institute of Statistics from the 2014 general population census. Hand swabbing of the 384 participants within households (320 in Abidjan and 64 in Taabo) was performed for the enumeration of E. coli and S aureus, using laboratory standard method and for the detection of SARS-CoV-2 by RT-qPCR. A binary logistic regression model was built with the outcome variable presence of Staphylococcus spp. on hands of respondents that was categorized into binary variables, Staphylococcus spp. (1 = presence, 0 = absence) for the Risk Ratio estimation. Place of living, sex, handwashing, education and age group were used to adjust the model to observe the effects of these explanatory variables. No presence of SARS-CoV-2 virus was detected on the hands of respondents in both sites. However, in urban Abidjan, only Staphylococcus spp. (Coagulase Negative Staphylococci) was found on the hands of 233 (72.8%, 95%CI: 67.7-77.4) respondents with the average load of 0.56 CFU/ Cm2 (95% CI, 0.52-0.60). Meanwhile, in rural Taabo, Staphylococcus spp. (Coagulase Negative Staphylococci) and E. coli were found on the hands of 40 (62.5%, 95%CI: 50.3-73.3) and 7 (10.9%, 95%CI: 5.4-20.9) respondents with the respective average load of 0.49 CFU/ Cm2 (95% CI, 0.39-0.59) and 0.08 CFU/ Cm2 (95% CI, 0.03-0.18). Participants living in rural Taabo were less likely to have Staphylococcus spp. on their hands (RR = 0.811; 95%IC: 0.661-0.995) compared to those living in urban Abidjan. No SARS-CoV-2 was detected on the hands of participants in both sites, suggesting that our study did not show direct transmission through hands. No E. coli was found in urban Abidjan while E. coli was found on the hands of participants in rural Taabo indicating poor hand washing and disinfection practices in rural Taabo. Living in urban Abidjan is statistically associated to having Staphylococcus spp. on hands. Further studies are necessary especially to understand to what extent the presence of Staphylococcus spp. on hands indicates a higher infection or fecal colonization rates in the case of E. coli.

Clinical applications of metagenomic next-generation sequencing in the identification of pathogens in periprosthetic joint infections: a retrospective study

BackgroundThis study aimed to evaluate the application of metagenomic next-generation sequencing (mNGS) technology to identify pathogens in periprosthetic joint infection (PJI).MethodsA retrospective analysis was conducted on 65 patients suspected of having PJI between April 2020 and July 2023. The patients were categorized into PJI (46 patients) and non-PJI (19 patients) groups based on the 2018 International Consensus Meeting criteria. Clinical data were collected, and both conventional bacterial culture and mNGS were performed. The diagnostic performance of the two methods was compared and analyzed.ResultsmNGS exhibited a sensitivity of 89.13%, a specificity of 94.74%, a positive predictive value of 97.62%, a negative predictive value of 78.26%, and an overall diagnostic accuracy of 90.77%. Compared to microbial culture, mNGS demonstrated superior diagnostic sensitivity while maintaining similar specificity. A total of 48 pathogens were successfully identified using mNGS, with Coagulase-negative staphylococci, Streptococci, Staphylococcus aureus, and Cutibacterium acnes being the most common infectious agents. Notably, mNGS was used to identify 17 potential pathogens in 14 culture-negative PJI samples, highlighting its ability to detect rare infectious agents, including Cutibacterium acnes (n = 5), Granulicatella adiacens (n = 1), Mycobacterium tuberculosis complex (n = 1), and Coxiella burnetii (n = 1), among others, which are not detectable by routine culture methods. However, mNGS failed to detect the pathogen in 4 culture-positive PJI patients, indicating its limitations. Among the 46 PJI patients, 27 had positive culture and mNGS results. The results of mNGS were concordant with those of culture at the genus level in 6 patients with PJI and at the species level in 18 patients. Furthermore, the present study revealed a significantly greater proportion of Staphylococcus aureus in the sinus tract group (45.45%) than in the non-sinus tract group (14.29%), indicating the association of this pathogen with sinus formation in PJI (P = 0.03). Additionally, there was no significant difference in the occurrence of polymicrobial infections between the sinus tract group (27.27%) and the non-sinus tract group (33.33%) (P = 0.37).ConclusionsMetagenomic next-generation sequencing can serve as a valuable screening tool in addition to traditional culture methods to improve diagnostic accuracy through optimized culture strategies.

Epidemiological Study of Pathogens in Spontaneous Bacterial Peritonitis in 2017-2024-A Preliminary Report of the University Hospital in South-Eastern Poland.

Spontaneous Bacterial Peritonitis (SBP) is a serious complication and a common cause of death in patients with liver cirrhosis. Between January 2017 and March 2024, a retrospective study was conducted involving 302 patients (>18 years old) with ascites treated at a tertiary referral center in south-eastern Poland. Microbiological analysis of the ascitic fluids was performed in all patients. The presence of microorganisms was found in samples from 17 patients, and 21 pathogens were isolated, including 15 Gram-positive bacteria and 6 Gram-negative bacteria. Staphylococcus epidermidis, MRCNS (methicillin-resistant coagulase-negative staphylococci, resistant to all beta-lactam antibiotics: penicillins, penicillins with beta-lactamase inhibitor, cephalosporins and carbapenems) was the main pathogen detected (19.05%, 4/21), followed by Enterococcus faecalis (9.52%, 2/21), Enterococcus faecium (9.52%, 2/21), Staphylococcus haemolyticus, MRCNS (4.76%, 1/21), Streptococcus mitis (9.52%, 2/21), Streptococcus parasanguinis (9.52%, 2/21), Micrococcus luteus (4.76%, 1/21) and Bacillus spp. (4.76%, 1/21). The following Gram-negative bacteria were also found in the specimens examined: Escherichia coli, ESBL (extended-spectrum β-lactamase producing E. coli) (4.76%, 1/21), Escherichia coli (4.76%, 1/21), Pseudomonas aeruginosa (4.76%, 1/21), Klebsiella oxytoca (9.52%, 2/21) and Sphingomonas paucimobilis (4.76%, 1/21). Gram-positive bacteria caused nosocomial infections in nine patients with SBP, Gram-negative bacteria caused nosocomial infections in two patients. In six patients with SBP, community-acquired infections caused by Gram-negative bacteria were found in three cases, Gram-positive bacteria in two cases, and in one case, community-acquired infection was caused by mixed Gram-positive and Gram-negative. Bacteria isolated from patients with hospital-acquired SBP showed higher drug resistance than those found in patients with non-hospital SBP. Bacterial infections in cirrhotic patients with complications may be responsible for their deteriorating health. Prompt intervention is critical to reducing mortality.

STERNAL WOUND INFECTION AFTER CARDIAC SURGERY: LOOKING FOR INTERACTIONS BETWEEN PERIOPERATIVE VARIABLES AND PATHOGEN AGENTS

Abstract Background Sternal wound infection (SWI) can be a major complication of cardiac surgery. Both the risk factors and the pathogens agents are well known today. Yet, possible interactions between perioperative variables and pathogens have not been explored. Methods Between Jan 1st, 2006 and Nov 30, 2023 (∼18 years), perioperative data of all patients undergoing cardiac operations through median sternotomy at the Cardio–Thoraco–Vascular Department of the University Hospital of Trieste, Italy, were recorded prospectically in a computed database. Every patient developing a sternal complication was followed in a dedicated outpatient clinic and, in the presence of infection, the causative pathogen was always searched for by cultural examination of tissue speciments. Different strategies of unsupervised clustering were applied to find groups of patients with similar clinical, surgical and microbiological profiles. Results Of 9,680 consecutive cardiac surgery patients, 516 (5.3%) experienced a SWI that involved superficial soft tissue in 25.6% of cases, deep soft tissue in 51%, sternal bone in 16.7%, or mediastinum in 6.8% of cases. Staphylococcus aureus, coagulase–negative Staphylococci, Enterobacteriaceae, and Pseudomonas aeruginosa were pathogens in 100 (19.4%), 158 (30.6%), 89 (17.2%) and 36 (7%) patients, respectively; other pathogens, polymicrobial and negative cultures were found in 27 (5.2%), 26 (5%) and 80 (15.5%) patients, respectively. Following statistical analyses, significant associations were found between the Pseudomonas aeruginosa etiology of SWI and some variables such as female gender (p&amp;lt;0.0001) and preoperative renal failure (p=0.008); significant associations between the Pseudomonas aeruginosa etiology were found also with more serious forms of sepsis (p=0.025), as well as with early postoperative death (p=0.02) and complications such as acute kidney injury (p=0.006), multiple transfusion (p=0.003), and prolonged mechanical ventilation (p=0.005). Conclusion For women having renal impairment and undergoing cardiac surgery through median sternotomy, in the case of SWI, the Pseudomonas aeruginosa etiology may be more frequent and a really life–threating complication.

Bullet-related bacterial wound infections among injured personnel at emergency site hospitals in Bahir Dar: prevalence, antimicrobial susceptibility and associated factors.

Bullet-related bacterial wound infection can be caused by high-velocity bullets and shrapnel injuries. In Ethiopia, significant injuries were reported that may cause severe wound infections, persistent systemic infections and may lead to amputation and mortality. The magnitude, antimicrobial susceptibility profiles, and factors associated with bacterial wound infections among patients with bullet-related injuries are not yet studied particularly at health facilities in Bahir Dar, Northwest Ethiopia. Therefore, this study was aimed to determine the prevalence, bacterial profiles, antimicrobial susceptibility profiles, and factors associated with bacterial infections among patients with bullet-related injuries at referral health facilities in Bahir Dar, Northwest Ethiopia. A Hospital-based cross-sectional study was conducted among patients with bullet-related injuries at three referral health facilities in Bahir Dar from May 25 to July 27, 2022. A total of 384 patients with bullet-related injuries were included in the study. Sociodemographic and clinical data were collected using a structured questionnaire. Wound swabs were collected aseptically and cultured on Blood and MacConkey agar following bacteriological standards. Biochemical tests were performed to differentiate bacteria for positive cultivation and antimicrobial susceptibility profiles of the isolates were done on Muller Hinton agar using the Kirby-Bauer disk diffusion technique according to the 2021 Clinical Laboratory Standard Institute (CLSI) guideline. The data were entered using Epi-Info version 7.3 and analyzed using SPSS version 25. Descriptive data were presented using frequency, percentages, figures, and charts. Logistic regression was carried out to identify factors associated with bacterial wound infections. P-value < 0.05 was considered statistically significant. The prevalence of bullet-related bacterial wound infection among three referral hospitals in Bahir Dar city was 54.7%. The most commonly isolated Gram-negative organism was Klebsiella spps 49 (23.3%) while among Gram-positive organism, Staphylococcus aureus 58 (27.6%) and coagulase-negative staphylococci (CONS) 18 (8.6%). Contamination, hospitalization and smoking habit were significantly associated with the presence of bullet-related bacterial wound infections. Over 97% multidrug resistant (MDR) bacterial isolates were identified and of theses, E. coli, Proteus species, Citrobactor, and Staphylococcus aureus were highly drug resistant. Increased prevalence of bullet-related bacterial wound infection was noticed in this study. S. aureus followed by Klebsiella species were most commonly isolated bacteria. High frequency of resistance to Ampicillin, Oxacillin, Cefepime, Ceftriaxone, Ceftazidime, Vancomycin, and Norfloxacin was observed. Therefore, proper handling of bullet injuries, prompt investigation of bacterial infections, monitoring of drug sensitivity patterns and antibiotic usage are critical.

Bacteriological Study of Post-Operative Wound Infection and its Antibiograms

INTRODUCTIONPostoperative wound infections are a significant complication of surgical procedures, which increases morbidity, mortality, prolonged hospital stay, and increased healthcare costs. The study was undertaken with an aim to investigate the etiological agents of postoperative wounds and their sensitivity to commonly used antibiotics. MATERIAL AND METHODSThis study was a descriptive cross-sectional prospective study, carried out at Universal College Of Medical Sciences-Teaching Hospital, Bhairahawa, Nepal, on 100 postoperatively wounded infected cases, during April 2023 – August 2023, Non Probability sampling method (Purposive sampling) was used, and specimens were collected by sterile cotton swabs and pus was aspirated with a sterile needle and syringe and processed using standard bacteriological techniques. Antibiotic sensitivity test was conducted by disc diffusion (Kirby-Bauer) method. RESULTSPostoperative wound infections caused by Gram negative bacilli were more frequent and predominant pathogens involved were Pseudomonas aeruginosa, followed by Klebsiella spp and Enterobacter aerogenes. Among Gram positive bacteria Staphylococcus aureus was predominant. Gram positive cocci were highly sensitive to Ampicillin, and Gram negative bacilli were highly sensitive to Ceftazidime, Gentamicin, and Amikacin. Coagulase negative staphylococci were resistant to all drugs tested. CONCLUSIONPseudomonas aeruginosa was the commonest etiological agent for postoperative wound infections. Gram positive cocci and E.coli were highly sensitive to Ampicillin and Gram negative bacilli were highly sensitive to Ceftazidime, Gentamicin, Amikacin. Staphylococcus aureus was resistant to vancomycin and Teicoplanin and coagulase staphylococci were resistant to all drugs tested. Gram negative bacilli were resistant to Polymyxin B and Tigecycline. Increasing resistance to commonly used antibiotics warrants the judicious use of antibiotics and establishment of antibiotic policy in the hospital.

Methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus produce antimicrobial substances against members of the skin microbiota in children with atopic dermatitis.

Coagulase-negative Staphylococcus (CoNS) species inhibiting Staphylococcus aureus has been described in the skin of atopic dermatitis (AD) patients. This study evaluated whether Staphylococcus spp. from the skin and nares of AD and non-AD children produced antimicrobial substances (AMS). AMS production was screened by an overlay method and tested against NaOH, proteases and 30 indicator strains. Clonality was assessed by pulsed-field gel electrophoresis. Proteinaceous AMS-producers were investigated for autoimmunity by the overlay method and presence of bacteriocin genes by polymerase chain reaction. Two AMS-producers had their genome screened for AMS genes. A methicillin-resistant S. aureus (MRSA) produced proteinaceous AMS that inhibited 51.7% of the staphylococcal indicator strains, and it was active against 60% of the colonies selected from the AD child where it was isolated. On the other hand, 57 (8.8%) CoNS from the nares and skin of AD and non-AD children, most of them S. epidermidis (45.6%), reduced the growth of S. aureus and other CoNS species. Bacteriocin-related genes were detected in the genomes of AMS-producers. AMS production by CoNS inhibited S. aureus and other skin microbiota species from children with AD. Furthermore, an MRSA colonizing a child with AD produced AMS, reinforcing its contribution to dysbiosis and disease severity.

Sonication protocols and their contributions to the microbiological diagnosis of implant-associated infections: a review of the current scenario.

Addressing the existing problem in the microbiological diagnosis of infections associated with implants and the current debate about the real power of precision of sonicated fluid culture (SFC), the objective of this review is to describe the methodology and analyze and compare the results obtained in current studies on the subject. Furthermore, the present study also discusses and suggests the best parameters for performing sonication. A search was carried out for recent studies in the literature (2019-2023) that addressed this research topic. As a result, different sonication protocols were adopted in the studies analyzed, as expected, and consequently, there was significant variability between the results obtained regarding the sensitivity and specificity of the technique in relation to the traditional culture method (periprosthetic tissue culture - PTC). Coagulase-negative Staphylococcus (CoNS) and Staphylococcus aureus were identified as the main etiological agents by SFC and PTC, with SFC being important for the identification of pathogens of low virulence that are difficult to detect. Compared to chemical biofilm displacement methods, EDTA and DTT, SFC also produced variable results. In this context, this review provided an overview of the most current scenarios on the topic and theoretical support to improve sonication performance, especially with regard to sensitivity and specificity, by scoring the best parameters from various aspects, including sample collection, storage conditions, cultivation methods, microorganism identification techniques (both phenotypic and molecular) and the cutoff point for colony forming unit (CFU) counts. This study demonstrated the need for standardization of the technique and provided a theoretical basis for a sonication protocol that aims to achieve the highest levels of sensitivity and specificity for the reliable microbiological diagnosis of infections associated with implants and prosthetic devices, such as prosthetic joint infections (PJIs). However, practical application and additional complementary studies are still needed.

A five-year retrospective antibiogram review in the paediatric burns unit at a tertiary South African Hospital

BackgroundThere is a global concern regarding increasing colonization and/or infection of paediatric burns patients with multi-drug-resistant organisms, especially in Africa. Surveillance of antimicrobial resistant patterns enables clinicians to opt for the most appropriate empiric antimicrobial agent according to the unit’s susceptibility profile. ObjectiveThis study sought to compile unit-specific antibiograms comparing the organism prevalence and their antimicrobial resistance trends in the paediatric burns unit, Chris Hani Baragwanath Academic Hospital (CHBAH) from January 2015 to December 2019. MethodsA retrospective, laboratory-based review was conducted of bacterial and fungal isolates including antimicrobial susceptibility testing (AST) data from blood cultures and tissue samples. Enterobacterales, non-fermenters, gram-positive organisms, and yeasts were analysed as a percentage of total positive blood cultures comparing 2015–2017 to 2018–2019 data. Analysis of antimicrobial resistance trends was performed for extended-spectrum beta-lactamases (ESBLs), carbapenem-resistant Enterobacterales (CRE), extensively-drug-resistant (XDR) Acinetobacter baumannii, and meticillin-resistant Staphylococcus aureus (MRSA) for the years 2015, 2017, and 2019. ResultsA total of 1243 blood culture isolates were studied with A.baumannii (208/1243;17 %), coagulase negative staphylococci (141/1243; 11 %) and Candida auris (53/1243; 4 %) representing the predominant gram-negative bacteria, gram-positive bacteria, and yeast, respectively. A significant decrease in ESBLs (p = 0.00) was noted with a rise in CREs (p = 0.00) during the study period. Majority of the A. baumannii were XDR (≥77 %) despite an appreciable decrease. A notable decrease in MRSA (p = 0.00) isolates was observed. Pseudomonas aeruginosa (72/275; 26 %) was the leading organism recovered from a total of 275 tissue isolates. ConclusionThe results of this study encourage review of the current antimicrobial choices in the unit for empiric antibacterial cover. Due to the low numbers of yeasts, we cannot comment on the institution of early antifungal strategies. We support reinforced infection prevention and control practices as well as antimicrobial stewardship initiatives.

Effects of bovine casein hydrolysate as a dry cow therapy on prevention and cure of bovine intramammary infection,

The objectives were to investigate the efficacy of bovine casein hydrolysate (bCNH) as a dry cow therapy on: 1) preventing new intramammary infection (IMI) postpartum of all bacteria and coagulase-negative staphylococci (CNS); 2) curing existing subclinical infections, mainly of CNS; and 3) affecting on milk yield, composition and somatic cell count (SCC) during the post-calving lactation.

Characterization of linezolid- and methicillin-resistant coagulase-negative staphylococci in a tertiary hospital in China

BackgroundRecently, linezolid-resistant staphylococci have become an emerging problem worldwide. Understanding the mechanisms of resistance, molecular epidemiology and transmission of linezolid-resistant CoNS in hospitals is very important.MethodsThe antimicrobial susceptibilities of all isolates were determined by the microdilution method. The resistance mechanisms and molecular characteristics of the strains were determined using whole-genome sequencing and PCR.ResultsAll the strains were resistant to oxacillin and carried the mecA gene; 13 patients (36.1%) had prior linezolid exposure. Most S. epidermidis and S. hominis isolates were ST22 and ST1, respectively. MLST typing and evolutionary analysis indicated most linezolid-resistant CoNS strains were genetically related. In this study, we revealed that distinct CoNS strains have different mechanisms of linezolid resistance. Among ST22-type S. epidermidis, acquisition of the T2504A and C2534T mutations in the V domain of the 23 S rRNA gene, as well as mutations in the ribosomal proteins L3 (L101V, G152D, and D159Y) and L4 (N158S), were linked to the development of linezolid resistance. In S. cohnii isolates, cfr, S158Y and D159Y mutations in the ribosomal protein L3 were detected. Additionally, emergence of the G2576T mutation and the cfr gene were major causes of linezolid resistance in S. hominis isolates. The cfr gene, G2576T and C2104T mutations, M156T change in L3 protein, and I188S change in L4 protein were found in S. capitis isolates.ConclusionThe emergence of linezolid-resistant CoNS in the environment is concerning because it involves clonal dissemination and frequently coexists with various drug resistance mechanisms.

Clinical characteristics and risk factors for right-sided infective endocarditis in Korea: a 12-year retrospective cohort study

Right-sided infective endocarditis (RSIE) is less common than left-sided infective endocarditis (LSIE) and exhibits distinct epidemiological, clinical, and microbiological characteristics. Previous studies have focused primarily on RSIE in patients with intravenous drug use. We investigated the characteristics and risk factors for RSIE in an area where intravenous drug use is uncommon. A retrospective cohort study was conducted at a tertiary hospital in South Korea. Patients diagnosed with infective endocarditis between November 2005 and August 2017 were categorized into LSIE and RSIE groups. Of the 406 patients, 365 (89.9%) had LSIE and 41 (10.1%) had RSIE. The mortality rates were 31.7% in the RSIE group and 31.5% in the LSIE group (P = 0.860). Patients with RSIE had a higher prevalence of infection with Staphylococcus aureus (29.3% vs. 13.7%, P = 0.016), coagulase-negative staphylococci (17.1% vs. 6.0%, P = 0.022), and gram-negative bacilli other than HACEK (12.2% vs. 2.2%, P = 0.003). Younger age (adjusted odds ratio [aOR] 0.97, 95% confidence interval [CI] 0.95–0.99, P = 0.006), implanted cardiac devices (aOR 37.75, 95% CI 11.63–141.64, P ≤ 0.001), and central venous catheterization (aOR 4.25, 95% CI 1.14–15.55, P = 0.029) were independent risk factors for RSIE. Treatment strategies that consider the epidemiologic and microbiologic characteristics of RSIE are warranted.

Metrisor: A novel diagnostic method for metritis detection in cattle based on machine learning and sensors

The Metrisor device has been developed using gas sensors for rapid, highly accurate and effective diagnosis of metritis. 513 cattle uteri were collected from abattoirs and swabs were taken for microbiological testing. The Metrisor device was used to measure intrauterine gases. The results showed a bacterial growth rate of 75.75 % in uteri with clinical metritis. In uteri positive for clinical metritis, the most commonly isolated and identified bacteria were Trueperella pyogenes, Fusobacterium necrophorum and Escherichia coli. Measurements taken with Metrisor to determine the presence of metritis in the uterus yielded the most successful results in evaluations of relevant machine learning algorithms. The ICO (Iterative Classifier Optimizer) algorithm achieved 71.22 % accuracy, 64.40 % precision and 71.20 % recall. Experiments were conducted to examine bacterial growth in the uterus and the random forest algorithm produced the most successful results with accuracy, precision and recall values of 78.16 %, 75.30 % and 78.20 % respectively. ICO also showed high performance in experiments to determine bacterial growth in metritis-positive uteri, with accuracy, precision and recall values of 78.97 %, 77.20 % and 79.00 %, respectively. In conclusion, the Metrisor device demonstrated high accuracy in detecting metritis and bacterial growth in uteri and could identify bacteria such as E. coli, S. aureus, coagulase-negative staphylococci, T. pyogenes, Bacillus spp., Clostridium spp. and F. necrophorum with rates up to 80 %. It provides a reliable, rapid and effective means of detecting metritis in animals in the field without the need for laboratory facilities.

Hospital-acquired bloodstream infections in critically ill cirrhotic patients: a post-hoc analysis of the EUROBACT-2 international cohort study

BackgroundHospital-acquired bloodstream infections are common in the intensive care unit (ICU) and have a high mortality rate. Patients with cirrhosis are especially susceptible to infections, yet there is a knowledge gap in the epidemiological distinctions in hospital-acquired bloodstream infections between cirrhotic and non-cirrhotic patients in the ICU. It has been suggested that cirrhotic patients, present a trend towards more gram-positive infections, and especially enterococcal infections. This study aims to describe epidemiological differences in hospital-acquired bloodstream infections between cirrhotic and non-cirrhotic patients hospitalized in the ICU regarding infection sources, microorganisms and mortality.MethodsUsing prospective Eurobact-2 international cohort study data, we compared hospital-acquired bloodstream infections sources and microorganisms in cirrhotic and non-cirrhotic patients. The association between Enterococcus faecium and cirrhosis was studied using a multivariable mixed logistic regression. The association between cirrhosis and mortality was assessed by a multivariable frailty Cox model.ResultsAmong the 1059 hospital-acquired bloodstream infections patients included from 101 centers, 160 had cirrhosis. Hospital-acquired bloodstream infection source in cirrhotic patients was primarily abdominal (35.6%), while it was pulmonary (18.9%) for non-cirrhotic (p < 0.01). Gram-positive hospital-acquired bloodstream infections accounted for 42.3% in cirrhotic patients compared to 33.2% in non-cirrhotic patients (p = 0.02). Hospital-acquired bloodstream infections in cirrhotic patients were most frequently caused by Klebsiella spp (16.5%), coagulase-negative Staphylococci (13.7%) and E. faecium (11.5%). E. faecium bacteremia was more frequent in cirrhotic patients (11.5% versus 4.5%, p < 0.01). After adjusting for possible confounding factors, cirrhosis was associated with higher E. faecium hospital-acquired bloodstream infections risk (Odds ratio 2.5, 95% CI 1.3–4.5, p < 0.01). Cirrhotic patients had increased mortality compared to non-cirrhotic patients (Hazard Ratio 1.3, 95% CI 1.01–1.7, p = 0.045).ConclusionsCritically ill cirrhotic patients with hospital-acquired bloodstream infections exhibit distinct epidemiology, with more Gram-positive infections and particularly Enterococcus faecium.

Bacterial diversity, antibiogram and nutritional assessment of cowhide (Ponmo) in Ilishan-Remo central market, Nigeria

The demand for cowhide (ponmo) is currently very high, particularly in Nigeria, due to rising commodity prices, including animal proteins, which has forced a larger percentage of the population who cannot afford meat, chicken, turkey or eggs to rely on other meat products such as “ponmo,” “kundi,” and “tinko” as an alternative source of protein. This research aims to identify microorganisms associated with ponmo, determine the antibiogram of the isolates, and assess the nutritional value of ponmo marketed in Ilishan-Remo central market. Six ponmo vendors were sampled for Dry White Ponmo (DWP), Wet White Ponmo (WWP), Wet Brown Ponmo (WBP) and Brown Ponmo Water (BPW) and transported in sterile containers to the Laboratory for analysis to determine the microbial load, sensitivity, and proximate analysis using standardized methods. For microbiological analysis, samples were tested in triplicate. All samples analyzed had a high microbial load count (from 1.1 x 106 to 1.4 x 107). The organisms isolated were Escherichia coli (34.21 %), Staphylococcus aureus (26.31 %), Klebsiella spp. (18.42 %), Pseudomonas spp. (13.15 %) and Coagulase-negative staphylococci (7.89 %). All the isolates were multidrug-resistant (MDR). Septrin had the highest resistivity (86.84 %) while gentamicin had the lowest resistance (7.89 %). Pefloxacin sensitivity was observed in 37 of the 38 isolates (97.37 % sensitivity). Ciprofloxacin and gentamicin came second and third (84.2 % and 73.68 % sensitivity) respectively. According to the proximate analysis, the WWP has more protein, fat, and fiber, whereas the WBP has more moisture. Food handlers should follow Good Hygiene Practices and take a Food Handlers Test regularly.

The Emergence of Linezolid-Resistant Staphylococcus Epidermidis in the COVID-19 Hospitalized Intubated Patients in North Khorasan, Iran.

The present study aimed to investigate secondary bacterial infections among patients infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Coagulase-negative Staphylococci can infect immunocompromised patients. Linezolid resistance among Staphylococcus epidermidis is one of the most critical issues. In 2019, 185 SARS-CoV-2-positive patients who were admitted to North Khorasan Province Hospital (Bojnurd, Iran), were investigated. Patients having positive SARS-CoV-2 reverse transcriptase real-time polymerase chain reaction (RT-PCR) test results, who had a history of intubation, mechanical ventilation, and were hospitalized for more than 48 hours were included. After microbiological evaluation of pulmonary samples, taken from intubated patients with clinical manifestation of pneumonia, co-infections were found in 11/185 patients (5.94%) with S. epidermidis, Staphylococcus aureus, and Acinetobacter baumani, respectively. Remarkably, seven out of nine S. epidermidis isolates were linezolid resistant. Selected isolates were characterized using antimicrobial resistance patterns and molecular methods, such as Staphylococcal cassette chromosome mec (SCCmec) typing, and gene detection for ica, methicillin resistance (mecA), vancomycin resistance (vanA), and chloramphenicol-florfenicol resistance (cfr) genes. All of the isolates were resistant to methicillin, and seven isolates were resistant to linezolid. Nine out of 11 isolated belonged to the SCCmec I, while two belonged to the SCCmec IV. It should be noted that all patients had the underlying disease, and six patients had already passed away. The increasing linezolid resistance in bacterial strains becomes a real threat to patients, and monitoring such infections, in conjunction with surveillance and infection prevention programs, is very critical for reducing the number of linezolid-resistant Staphylococcal strains. A preprint of this study was published at https://europepmc.org/article/ppr/ppr417742.