Coagulase-negative Staphylococci Research Articles

Novel sequence types and low levels of antimicrobial resistance associated with clinical mastitis in sheep flocks across Scotland.

This research paper aimed to demonstrate that mammary secretions provided by sheep farmers across Scotland from cases of clinical mastitis are free from environmental contamination, as well as to provide information on the major bacterial causes of disease and levels of antimicrobial resistance. Mastitis represents one of most significant diseases of small ruminant production worldwide. Staphylococcus aureus, Mannheimia haemolytica, Streptococcus uberis and coagulase-negative Staphylococcal species are common pathogens isolated from cases of sheep mastitis. Sampling kits supplied to 23 farms provided 33 samples for bacteriology, antimicrobial susceptibility testing and genetic analysis. Of the bacterial isolates identified, 60% were S. aureus, 23% M. haemolytica and 7% coagulase-negative staphylococci. Low levels of antimicrobial resistance were identified in the S. aureus isolates which provided novel multi-locus sequence types. In conclusion, this proof-of-concept survey demonstrated that mammary secretions free from environmental contamination may be provided by sheep farmers. It also provided data on the prevalence of antimicrobial resistance associated with clinical mastitis in sheep and will inform on the scale required for larger surveys aiming to improve current strategies for mastitis control in sheep flocks across the UK.

Bacteriological Profile and Antibiotic Susceptibility Pattern of Isolates from Suspected Neonatal Septicemia Patients in Different Hospitals of Chattogram

Background: Bacterial blood stream infection is an important cause of morbidity and mortality in neonates. This study was undertaken to identify the bacterial isolates from suspected neonatal septicemia patients and to understand their antimicrobial susceptibility pattern in Chattogram. Materials and methods: A cross-sectional descriptive type of study was done for a period of two years from January 2022 to December 2023. Blood samples from 340 neonates with clinically suspected septicemia were taken for automated culture and susceptibility test was conducted in Bacteriology Laboratory of IbneSina, Chattogram. The samples were collected and processed following standard microbiological techniques and an antibiotic susceptibility test was done on pure culture isolates using disc-diffusion method for the commonly used antibiotics. The data were analyzed by using SPSS version 20 and the results were summarized by using tables and graphs. Results: Out of 340 blood culture done, 62 (18.24%) were positive. Among them 61.3% were of early onset sepsis. The predominant bacteria isolated was Klebsiella spp. 27 (43.6%) followed by Coagulase negative staphylococci 12(19.4%), Salmonella typhi 10 (16.1%), E. coli 6 (9.6%) and Pseudomonas 5 (8.0%). Antibiotic susceptibility tests showed that the most sensitive antibiotics to Gram-negative organisms wereImipenem (81-100%), Tazobactam-Piperacillin (74-100%), Amikacin (67-90%), Ceftriaxone (60-100%) and Levofloxacin (63-80%). Maximum resistance among Gram-negative organisms were seen in Ampicillin (60-100%), Cotrimoxazole (60-100%) and Cefixime (30-80%). Among Gram-positive organisms, all strains (100%) were sensitive to Linezolid and Vancomycin. Other alternates with good sensitivity were Amikacin (92%), Imipenem (83%), Ceftriaxone (83%) and Levofloxacin (75%). While maximum resistance was seen to Ampicillin (83%), Amoxiclav (75%), Cefixime (75%) and Ciprofloxacin (75%). Conclusions: In the present study, most of the pathogens isolated from blood cultures were Gram negative and they showed high resistance to commonly used antibiotics. Therefore, rational use of antibiotics after sensitivity testing should be practiced. IAHS Medical Journal Vol 7(1), June 2024; 68-73

Bacterial profile and antimicrobial susceptibility patterns of common neonatal sepsis pathogens in Gulf Cooperation Council countries: A systematic review and meta-analysis

Introduction: Neonatal sepsis (NS) is a major healthcare burden in Gulf Cooperation Council (GCC) countries, with a prevalence higher than the global average. Microbial drug resistance has major implications for mortality and morbidity from NS. Objective: To synthesize data regarding the patterns of causative bacteria of NS in the GCC and their antimicrobial susceptibility profiles. Methods: Following the exploration of four electronic databases, i.e., EBSCOhost, ProQuest, PubMed/MEDLINE, and ScienceDirect, eligible studies were identified (i.e., published between 2013 and 2023 and reported bacterial profile and/or antimicrobial susceptibility patterns). The outcomes included the pooled prevalence of bacteria and their susceptibility patterns. Proportion meta-analysis was performed for each outcome of interest. Results: Fifteen studies were eligible (total positive cases = 2,473). Coagulase-negative Staphylococci (CoNS) (28.1%) were the most common gram-positive causative pathogen, followed by group B Streptococcus (GBS) (16.2%) and Staphylococcus aureus (9.9%); for gram-negative, Escherichia coli (12.7%) and Klebsiella species (11.4%) were most common. The susceptibility rates of these bacteria to first-line antibiotics were high; gram-positive bacteria had the highest susceptibility to ampicillin (72.8–98%), and gram-negative bacteria was most susceptible to amikacin (94.6–98%). Additionally, both gram-positive (67–77%) and negative (87–93%) bacteria exhibited high susceptibility to gentamicin. Conclusion: The most common pathogens among NS patients were gram-positive. The pathogens, irrespective of stain test, were susceptible to the current antibiotic therapy. We recommend the judicious use of empirical antibiotic therapy to prevent the growing risk of antimicrobial resistance.

Sex-disaggregated analysis of central venous catheter-related bloodstream infections in patients with cancer.

Men are generally more susceptible to bacterial infections than women. Central venous catheters (CVCs), often used to administer systemic treatment in patients with cancer, are an important source of infection. However, little is known about sex-specific differences of CVC-related bloodstream infections (CRBSIs) in patients with cancer. This study aimed to compare CRBSIs in men vs. women in a large cohort of patients with cancer. Data were derived from the SECRECY registry including non-selected patients with centrally inserted non-tunneled internal jugular or subclavian vein CVCs in 10 hematology and oncology sites in Germany. Only CRBSIs classified as definite CRBSI (dCRBSI) or probable CRBSI were included, and the combination of both was summarized as dpCRBSI. CVCs were matched 1:1 for underlying disease, anatomic site of CVC insertion, type of CVC dressing, antimicrobial coated CVC, complicated CVC insertion and CVC in situ time by propensity score matching (PSM). Endpoints were CRBSI rates and incidences in CVCs inserted in men vs. women. A total of 5075 CVCs registered from March 2013 to March 2024 were included in the analysis, of which 3024 comprises the PSM cohort. 1512 (50.0%) CVCs were inserted in men. Underlying diseases mainly were hematological malignancies (96.4%). While there was no statistically significant difference between men and women in the dCRBSI rate (5.4% vs. 4.1%; p=0.12) and the dCRBSI incidence (3.8 vs. 2.9/1000 CVC days; p=0.11), the rate of dpCRBSI (9.9% vs. 6.7%; p=0.002) and the dpCRBSI incidence (7.0 vs. 4.7/1000 CVC days; p=0.002) were significantly higher in men vs. women. The proportion of coagulase-negative staphylococci as causative agent of both dCRBSI and dpCRBSI was higher in men than in women (58.8% vs. 41.2%; p=0.07, and 61.5% vs. 38.5%; p=0.002, respectively). A multivariable regression revealed neutropenia as an independent risk factor for dCRBSI and male sex as risk factor for dCRBSI and dpCRBSI. In patients with hematological malignancies, men have a higher risk of CRBSI than women. This finding may be attributed to the high number of jugular vein inserted CVCs which in men may be associated with higher rates of skin colonization than in women. Special preventive measures such as earlier removal of CVCs in men may be studied in future.

A Comparative Study of the Incidence and Severity of Surgical Site Infection Following Emergency and Elective Abdominal Surgeries in a Tertiary Care Hospital

Background: Surgical site infection is a medical condition that develops up to 30 days after the surgery if no implants have been placed, and as long as 12 months if the patient has an implant device. SSIs pose a substantial barrier to healing and resumption of normal activities. SSIs and its side-effects have been noted as one of their primary contributors to the morbidity following surgery. This study will look at the incidence and severity of infections at the surgical site after both emergency and elective abdominal surgery. Methods: This is prospective observational research in patients who underwent Surgeries in either elective or emergency settings. Southampton wound assessment scale and the ASEPSIS wound scoring system were used in grouping the patients with SSI followed by each patient's SSI type was further recorded. The study also documented other factors, such as hospital stay and interventions. Results: There were one fifty participants in this study. 23 patients experienced SSI (6 elective cases and 17 emergency cases), while 127 people did not. The pathogens most commonly cultured were coagulase negative staphylococcus (CoNS, 8 cases), after which came Escheria coli. (4 cases). Conclusion: A higher prevalence of SSI is linked to factors including the patient's advancing age, a dirty wound, prolonged surgery, usage of drains, nutritional deficiency, anemia, and diabetes. The hospital personnel need to be more careful about following aseptic procedures and have more awareness of infection management.

Evaluation of mucosal barrier disruption due to Staphylococcus lugdunensis and Staphylococcus epidermidis exoproteins in patients with chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a persistent inflammatory condition of the sinus mucosa. While Staphylococcus aureus has been shown to play a significant role in mucosal barrier disruption in CRS patients, coagulase-negative staphylococci (CoNS) such as Staphylococcus epidermidis and Staphylococcus lugdunensis are also implicated in CRS pathophysiology. This study investigates the effects of exoproteins secreted by planktonic and biofilm forms of clinical isolates of S. epidermidis and S. lugdunensis on the nasal epithelial barrier. Thirty-one clinical isolates of CoNS were grown in planktonic and biofilm forms, and their exoproteins were concentrated. The epithelial barrier structure was assessed by measuring transepithelial electrical resistance (TEER) and the permeability of fluorescein isothiocyanate-dextran. Toxicity and inflammatory response were also studied. Our findings demonstrate that exoproteins from all planktonic forms of S. lugdunensis disrupted the mucosal barrier, whereas only nine of 16 biofilm-derived exoproteins had similar effects. Conversely, 11 of 15 exoproteins from planktonic S. epidermidis significantly disrupted barrier integrity; however, biofilm exoproteins did not. The study also showed that some exoproteins from planktonic S. epidermidis significantly reduced cell viability, while exoproteins from planktonic and biofilm forms of S. lugdunensis and biofilm S. epidermidis did not induce any statistically significant change in cell viability. Notably, four of 16 biofilm exoproteins from S. lugdunensis induced higher interleukin-6 (IL-6) secretion, whereas none of the S. epidermidis isolates showed a significant increase in IL-6 secretion. Our results suggest that CoNS exoproteins may contribute to CRS etiopathogenesis.

BLOODSTREAM INFECTIONS AND ITS ANTIBIOGRAM OF INTENSIVE CARE UNITS IN A TERTIARY CARE HOSPITAL OF CENTRAL INDIA

Objective: To perform bacteriological analysis and to study drug susceptibility patterns of isolates from bloodstream infections. Methods: This retrospective study was conducted in the microbiology department of NSCB Medical College, Jabalpur, spanning from July 2023 to December 2023. The study included blood culture samples from all adult intensive care unit patients of the medical college. Blood samples were collected with aseptic guidelines and cultured for 7 days. Growths were identified using standard biochemical tests and subjected to sensitivity testing according to Modified Kirby-Bauer’s disk diffusion method. Data for the source of blood collection and duration of incubation were noted and compared. Results: A total of 100 (21.7%) pathogens were isolated from 460 bacteremia suspect patient blood specimens. Pseudomonas spp. Were predominant organisms recovered followed by Klebsiella spp. and Staphylococcus aureus, coagulase-negative staphylococci, and Acinetobacter spp. were the primary pathogens isolated. Carbapenems, glycopeptides, and aminoglycosides were the most effective drugs for treating bacteremia. Conclusions: Early diagnosis and proper antimicrobial therapy lead to successful treatment of sepsis and decreased morbidity and mortality. Antibiogram of a particular area helps in rationalizing verified treatment strategies.

Occurrence of virulence genes icaADBC and antibiotic resistance genes blaZ, mecA, and aac(6’)-Ie-aph (2’’)-Ia in coagulase-negative staphylococci isolates from neonates with sepsis at a regional referral hospital in Dar es Salaam, Tanzania

BackgroundCoagulase-negative staphylococci (CoNS) have been linked to severe conditions such as bloodstream infection, with biofilm formation regarded as the major virulence mechanism. This study determined virulence genes (VGs) (icaA, icaB, icaC, and icaD) responsible for biofilm formation and antibiotic resistance genes (ARGs) (blaZ, mecA, and aac(6’)-Ie-aph(2’’)-Ia) in CoNS isolated from blood samples of 70 neonates with sepsis in Dar es Salaam, Tanzania. We used VITEK®MS (BioMérieux, France) for speciation and phenotypically detected biofilm production using the Congo red agar. Polymerase chain reaction was performed for ARGs and VGs detection; principal component analysis was used to ascertain their relationship.ResultsOut of 70 CoNS, Staphylococcus epidermidis, 27 (36.8%) was the most commonly isolate, subsequently to Staphylococcus haemolyticus, 24 (34.3%). The intercellular adhesion genes (ica) were detected in all isolates, with IcaD found in 70 (100.0%), followed by icaB 69 (98.6%), icaC 69 (98.6%), and icaA 65 (92.9%). Four virulence gene combinations (icaADBC, icaBCD, icaACD, and icaABD) were detected, predominantly icaADBC 63 (90.0%). Sixty-one (87.1%) isolates harbored three ARGs, mostly the mecA gene 69 (98.6%), followed by blaZ 67 (95.7%) and aac (6’)-Ie-aph (2’’)-Ia, 65 (92.7%). We observed a moderate positive correlation between mecA and icaA genes (r = 0.4341). Sixty-five (97.0%) isolates resistant to penicillin harbored blaZ genes, and all 62 (100%) resistant to oxacillin harbored mecA genes. Of the 66 isolates resistant to gentamycin, 62 (93.9%) harbored the aac (6’)-Ie-aph (2’’)-Ia gene. The mecA gene contributed most of the resistance, followed by aac(6’)-Ie-aph(2’’)-Ia genes. However, the icaA and icaD genes significantly influenced the virulence of CoNS.ConclusionsMost CoNS isolated from blood samples of neonates with sepsis harbor a variety of clinically relevant virulence and resistance genes, indicating their ability to cause severe infections that are difficult to treat. Significantly, 59 (84.3%) isolates were phenotypically penicillin, gentamycin, and oxacillin resistant; the antibiotics recommended in the national guidelines for empiric treatment of neonatal sepsis.

Time to positivity of Coagulase Negative Staphylococcus In Neonatal Blood Cultures as an adjunct tool to help discriminate between sepsis and contamination.

To assess the usefulness of time to positivity (TTP) to distinguish between sepsis and contamination in coagulase-negative staphylococci (CoNS) isolates. Unicentric retrospective observational. Medical records of 168 patients with suspected sepsis and positive blood culture for CoNS were reviewed. Patients were subdivided into sepsis (29%) and probable contamination (71%). Logistic regression analyses were performed to evaluate different risk factors and clinical signs and symptoms associated with sepsis. TTP cut-off value that best discriminated sepsis from contamination was found to be 18 h. Regression analysis revealed that TTP ≤ 18 h, gestational age ≤32 weeks, taquycardia/bradycardia and hypoactivity/lethargy were independent predictors of sepsis. TTP is useful in distinguishing sepsis from contamination, especially in neonates with lower gestational age (<32 weeks). The clinical signs that most increase the discriminatory power of TTP are the presence of tachycardia/bradycardia or hypoactivity.

Are SNPs Linked to Somatic Cell Score Suitable Markers for the Susceptibility to Specific Mastitis Pathogens in Holstein Cows?

Mastitis in cattle is often caused by microorganism infections in the udder. The three most common pathogens are esculin-positive streptococci (SC+), coagulase-negative staphylococci (CNS), and Escherichia coli (E. coli). In a previous study, 10 SNPs were associated with somatic cell score and mastitis in diverse Holstein populations. We tested these SNPs for their effects on individual pathogen presence. Milk and pathogen samples of 3076 Holstein cows were collected from four farms. Samples were excluded if multiple pathogens were present at the same time. Records of the same pathogen within 14 days of each other were counted as one infection. This resulted in 1129 pathogen-positive samples. Cases and controls were in ratios of 20:80 for SC+, 8:92 for CNS, and 11:89 for E. coli. The lasso, backward, and forward methods were used to narrow down SNPs associated with pathogen presence. The suitability of the SNPs to separate the samples into cases or controls for each pathogen was indicated using ROC curves. The Cochran-Armitage (CAT) and the Jonckheere-Terpstra (JTT) tests evaluated the influence of the SNPs on pathogen presence. Finally, a generalised linear mixed model (GLMM) including fixed environmental effects and a random sire effect was fitted to the binary trait of pathogen presence to test for association. In total, six out of the 10 investigated SNPs showed associations with pathogen presence based on the forward method: Two SNPs each for SC+ (rs41588957, rs41257403) and CNS (rs109934030, rs109441194), and three for E. coli (rs109934030, rs41634110, rs41636878). The CAT and GTT tests linked four SNPs (rs41588957, rs41634110, rs109441194, rs41636878) to pathogen presence, two of which were confirmed with the GLMM (rs41634110, rs109441194), with effects on CNS and E. coli. The SNPs linked to CNS and those linked to E. coli explained 13.2% and 13.8% of the variance, compared to 19% and 18.4%, respectively, of the full model with all 10 SNPs. Half of the SNP genotypes previously linked to lower SCS also decreased the probability for pathogen presence and might therefore be targets not just for lower SCS but for a better pathogen resistance. Trial Registration: Not applicable, no new data were collected for this study.

Impact of COVID-19 on the Prevalence and Drug Resistance of Bacteria Isolated From Bacterial Meningitis Cerebrospinal Fluid in Shandong Province: A Multicenter Retrospective Study.

Our objective was to evaluate the ramifications of the 2019 coronavirus disease (COVID-19) pandemic on the microbial profile and antimicrobial resistance patterns of bacteria isolated from cerebrospinal fluid (CSF) specimens of patients with bacterial meningitis. We conducted a retrospective analysis of laboratory results and clinical records about positive CSF cultures reported by the SPARSS network from 2017 to 2023. The study covered three distinct periods: January 2017 to December 2019 (before the COVID-19 pandemic), January 2020 to December 2022 (during the COVID-19 pandemic), and January 2023 to December 2023 (after the COVID-19 pandemic), with a total of 5793 CSF isolates collected. Notably, the proportion of male patients (61.3%) was higher than that of females. After COVID-19, we observed a notable shift in the seasonal peak of CSF pathogens, with a delay of approximately 3 months. Remarkable alterations were evident in both pediatric and adult CSF isolate profiles. In children, the predominant pathogens included coagulase-negative Staphylococcus (CoNS), Streptococcus pneumonia, and Escherichia coli. Notably. After COVID-19, there was a significant decrease in the proportion of CoNS (p = 0.0039) and a notable increase in E. coli (p = 0.0067). In adults, the top three pathogens were CoNS, Acinetobacter baumannii, and Klebsiella pneumoniae. After the pandemic, we observed a significant reduction in the prevalence of A. baumannii (p = 0.0059), while the proportions of K. pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis increased significantly (p < 0.05). Additionally, among multidrug-resistant bacteria, the detection rate of carbapenem-resistant E. coli escalated (p = 0.0375). Antimicrobial susceptibility analysis indicated a declining trend in resistance rates for CoNS and A. baumannii to certain antibiotics following the pandemic. Conversely, resistance to imipenem in A. baumannii increased. In conclusion, the COVID-19 pandemic has significantly influenced the composition, antimicrobial resistance patterns, and epidemiological dynamics of CSF-isolated bacteria in Shandong province. To effectively address these changes, ongoing and dynamic surveillance of pathogen trends and antimicrobial resistance rate is essential.

Evaluation of the Microbiology of Removed Punctal Plugs and Intracanalicular Devices.

The purpose of this observational study was to characterize the microorganisms colonizing punctal plugs and intracanalicular stents. Devices were removed from participants who previously underwent placement of punctal plugs for tear insufficiency and lacrimal stents for dacryocystorhinostomy and canalicular reconstruction procedures. After removal of the devices, they were cultured for organisms both with and without sonication to loosen any biofilms or adherent microorganisms. Primary outcome measures included culture positivity, identification of isolated microorganisms, recovery of microorganisms from culture after sonication, and clinical evidence of ocular infection. There were no cases of clinical infection. A total of 181 specimens were processed (174 punctal plugs, seven intracanalicular stents), of which 98 (54%) were culture positive. Of the punctal plugs, 92 (52.9%) were culture positive, including 42 with a single organism isolated, whereas 22 yielded two organisms, 7 yielded three organisms, and the remaining 21 yielded a polymicrobial culture with four or more organisms. The most common isolates from punctal plugs were coagulase negative staphylococci (27.6%), diphtheroids (16.4%), and streptococcus viridans (10.2%). Those plugs with polymicrobial culture results grew a mixture of organisms most consistent with skin or upper respiratory flora. Of the intracanalicular stents, 6 (85.6%) were culture positive. Punctal plugs and intracanalicular devices can become colonized with bacteria composed of oropharyngeal flora, skin flora, and other rare but potentially significant pathogens.

The effect of medical face masks on inhalation risk of bacterial bioaerosols in hospital waste decontamination station

There is insufficient research on bioaerosols in hospital waste decontamination stations. This study aimed to investigate the effect of three-layer and N95 masks in reducing the inhalation risk of bacterial bioaerosols in a waste decontamination station at a teaching hospital. Active sampling was conducted on five different days at three locations: the yard, resting room, and autoclave room in three different modes: without a mask, with a three-layer mask, and with an N95 mask. Bacterial bioaerosols passing through the masks were identified using biochemical tests and polymerase chain reaction (PCR). The median concentration and interquartile range (IQR) of bacterial bioaerosols was 217.093 (230.174) colony-forming units per cubic meter (CFU/m3), which is higher than the recommended amount by Pan American Health Organization (PAHO). The resting room had high contamination levels, with a median (IQR) of 321.9 (793.529) CFU/m3 of bacterial bioaerosols. The maximum concentration of bioaerosols was also recorded in the same room (2443.282 CFU/m3). The concentration of bacterial bioaerosols differed significantly between using a three-layer or N95 mask and not using a mask (p-value < 0.001). The non-carcinogenic risk level was acceptable in all cases, except in the resting room without a mask (Hazard Quotient (HQ) = 2.07). The predominant bacteria were Gram-positive cocci (33.98%). Micrococci (three-layer mask = 51.28%, N95 mask = 50%) and Coagulase-negative Staphylococci (three-layer mask = 30.77%, N95 mask = 31.82%) were the most abundant bioaerosols passing through the masks. The results obtained are useful for managerial decisions in hospital waste decontamination stations to reduce exposure to bioaerosols and develop useful guidelines.

Surveillance of Antimicrobial Resistance Bacteria in a Healthcare Facility at an Industrial Site in Saudi Arabia.

This study aimed to perform surveillance and identify antimicrobial resistance (AMR) in the most common pathogenic bacteria in a healthcare facility in Rabigh City, Saudi Arabia. A total of 1,933 samples were processed from patients during the study period from January 2022 to June 2022. Identification and antimicrobial susceptibility of the cultured isolates were performed using the MicroScan system. Out of the 1,933 tested samples, 11.1% (n = 214) were positive for bacterial growth. A relatively higher percentage of isolates was recovered from patients older than 50 years (55.9%). Gram-negative bacteria (67.3%) were significantly more prevalent than Gram-positive bacteria (32.7%). The Gram-negative pathogenic bacteria comprised mainly Escherichia coli and Klebsiella pneumoniae, followed by Pseudomonas aeruginosa. Staphylococ-cus epidermidis and coagulase-negative staphylococci were found at relatively high abundance in Gram-positive bacteria. Increased resistance to carbapenem antibiotics was observed in K. pneumoniae. In Gram-positive bac¬teria, > 50% of the isolates of S. epidermidis were resistant to 13 tested antimicrobial agents. This study provided an overview of the distribution of pathogenic bacteria and antimicrobial susceptibility of the prevalent Gram-negative and Gram-positive pathogenic bacteria in a major healthcare facility in Saudi Arabia. It highlights the importance of continuously monitoring AMR bacteria in healthcare settings to ensure the effective use of antibiotics for treatment.

Comparison of the aetiology, microbiological isolates and antibiotic susceptibilities of endophthalmitis between children and adults in southern China: a retrospective, cohort study

ObjectivesTo compare aetiology, microbiological isolates and antibiotic susceptibilities of endophthalmitis between children and adults.DesignRetrospective observational study.ParticipantsPatients admitted to Zhongshan Ophthalmic Center between January 2013 and December 2019 with clinically diagnosed...

The quality and technological parameters of milk obtained from dairy cows with subclinical mastitis

Mastitis is one of the most common diseases in dairy cattle. It significantly reduces milk quality and yield, thus incurring economic losses for farmers. This study investigates the impact of various bacterial pathogens on the somatic cell count, milk composition, and technological properties of milk samples from 302 clinically healthy Polish Holstein-Friesian cows kept under intensive rearing conditions. Of the 462 milk samples analyzed, 85.06% were contaminated with bacteria. The majority were coagulase-negative staphylococci (52.60%).-Escherichia coli, Streptococcus dysgalactiae, Streptococcus uberis, or Staphylococcus aureus, or Streptococcus agalactiae, a major pathogen, were identified in 16.66% of samples; their presence was associated with higher SCC levels. Additionally, contamination with S. aureus or S. agalactiae had prolonged clotting time, adversely affected curd and whey quality, with curd yield remaining unaltered. Bacterial contamination did not appear to significantly impact the yield of milk or its main components, viz. protein, casein, lactose, fat, total solids, solid nonfat, free fatty acid or citric acid. Although pH, freezing point depression (FDP), and acidity also remained unaffected by bacterial contamination, they were significantly influenced by herd-year-season of calving and herd-year-time of sampling interaction effects. The results indicate that the presence of bacteria causing subclinical mastitis negatively influences milk processing potential. However, fixed linear regression indicated that the number of colony-forming units (cfu/ml) only had a significant influence on FPD and clotting time, and as such, the number of bacteria in a sample did not influence milk yield or quality during subclinical chronic mastitis.

Antibiotic resistance profile of &lt;i&gt;Coagulase-negative staphylococci&lt;/i&gt; species isolated from subclinical mastitis in Colombian dairy herds

Boyacá is Colombia's fifth-largest milk-producing department. Previous studies have shown the importance of Coagulase-negative Staphylococci (CNS) species as causes of subclinical mastitis in dairy herds. This work aimed to determine the antibiotic resistance profile in CNS obtained from subclinical mastitis, and the presence of the mecA gene. CNS DNA was taken from a previous study of the research group, and specific primers were used for the detection of the mecA gene in isolates that showed antibacterial resistance to at least one of the following antibiotics: ampicillin, tetracycline, streptomycin, oxacillin, penicillin, and enrofloxacin. The results show different patterns of antibiotic resistance in the CNS isolates despite being obtained from the same herd. In addition, S. chromogenes and S. epidermidis were the most prevalent pathogens, and with the highest presence of the mecA gene (33.4 and 37.5% respectively). The results are like those found in other countries and worldwide studies, however, the presence of the mecA gene was not associated in some species such as S. capitis, S. sciuri, and S. haemolyticus with phenotypic resistance to oxacillin or penicillin, therefore, more research is required on other genes possibly associated with this.

Postoperative heart valve infection, when and which bacteria: a nationwide cohort study

Abstract Background In patients undergoing heart valve surgery, subsequent bacteremia and infective endocarditis are feared events due to the associated high mortality. Knowledge on the incidence and specification of bacteremia following left-sided valve surgery are sparse and may have implications for prophylactic strategies and follow-up. Purpose To examine the six months incidence of bacteremia and infective endocarditis following left-sided heart valve surgery. Methods In the period from January 2010 to December 2021 all patients undergoing left-sided valve surgery were identified using Danish nationwide registries. Patients were followed until a maximum of six months, end of study, emigration, death, or outcome of interest (i.e., bacteremia or infective endocarditis). Cumulative incidence curves were computed with death as a competing risk stratified on bacterial species and for subgroups of interest: type of valve surgery, age, and sex. Results A total of 14,305 patients were included in the study. The majority of the study population were male (68.6%), and the median age was 70.2 years (25th-75th percentile 62.0-76.0 years). In total, 10,469 (73.2%) of the study population underwent aortic valve surgery, 3,497 (24.5%) underwent mitral valve surgery, while 339 (2.4%) underwent surgery on both valves. The cumulative incidence of bacteremia at six months of follow-up was 2.4% (95% CI 2.2-2.7%), Figure 1. For the overall study population, the most frequently occurring bacteremia was with Coagulase-negative Staphylococci (28%) and Staphylococcus aureus (14%). Within 30 days 0.35% of the patients had bacteremia with coagulase-negative staphylococci while this was 0.68% at six months of follow-up. For Staphylococcus aureus this was 0.19% and 0.34%, respectively. The cumulative incidence of infective endocarditis at six months of follow up was 1.0% (95% CI 0.8-1.2%). The majority of the infective endocarditis incidents were blood culture negative (27%) or caused by Enterococci (19%), Streptococci (17%) or Coagulase-negative Staphylococci (17%) while Staphylococcus aureus accounted for 14%. In crude analysis, simultaneous surgery on the mitral and aortic valve was associated with a statistically significant higher rate of bacteremia (P=0.004). Similarly, higher age was associated with a statistically significant higher rate of bacteremia (P&amp;lt;0.001). On the contrary, in crude analysis, no difference in the risk of bacteremia was found between sexes (P=0.9). Conclusions Bacteremia following left-sided heart valve surgery occurred in little over 2%. The majority was with Staphylococci, and half of these occurred within 30 days of the surgery. There is a continued need to optimize prophylactic strategies.

Bacteremia after transcatheter aortic valve implantation: a nationwide cohort study

Abstract Background Bacteremia and infective endocarditis (IE) are rare but severe complications to transcatheter aortic valve implantation (TAVI). However, data on early bacteremia and microbiological etiological profile are scarce. Purpose The study aimed to investigate the incidence of bacteremia and IE within six months after TAVI. Methods Using Danish nationwide registries, we identified all patients who underwent TAVI from 2012 to 2021. These patients were matched 1:1 by age, sex, and index-year with individuals who underwent elective coronary angiography (CAG). The primary outcomes were bacteremia and IE within six months. Outcomes were compared with cumulative incidence functions and adjusted hazard ratios (HR). All patients were followed six months from the index date until the outcome of interest, death, emigration, or end of study (December 31st, 2021), whichever came first. Results We identified 5,990 patients undergoing first-time TAVI, of whom 56 % were men, and the median age was 81 years [IQR 77–85]. All patients were matched with controls undergoing CAG (56% men, median age 81 [IQR 77-85]). Patients undergoing TAVI had more comorbidities than controls. The six-month cumulative incidence of bacteremia was 4.2% [95% CI 3.7-4.7] and 2.6% [95% CI 2.2-3.0] after TAVI and CAG, respectively, corresponding to an adjusted HR of 1.57 (95% CI 1.27-1.96) (Figure 1). The common bacterial etiologies for bacteremia after TAVI were Streptococci (20%), Coagulase-negative staphylococci (CoNS) (19%), and Enterococci (18%). After CAG, CoNS (22%) and Staphylococcus aureus (16%) were the most frequent. By six months, 1.1% [95% CI 0.9-1.4] and 0.2% [95% CI 0.1-0.3] developed IE after TAVI and CAG, respectively, with an adjusted HR of 20.01 (95% CI 5.97-67.48). Conclusion In this nationwide cohort study, the risks of bacteremia and infective endocarditis within six months post-TAVI were significantly higher than in the matched coronary angiography population. Bacteremia post-TAVI was characterized by significantly more Enterococci spp. These results could have implications in the selection of peri-procedural antibiotics, as commonly used antibiotic regimens do not cover Enterococci spp.Cumulative incidence of bacteremia

Changes in length of hospital stay for infective endocarditis - data from before and after the POET trial

Abstract Background The results from the Partial Oral Treatment of left-sided Endocarditis (POET) trial was published in August 2018 and established non-inferiority of a switch to oral step-down antibiotic treatment in stabilized patients with infective endocarditis (IE). However, data on length of hospital stay and safety following the POET trial are warranted. Purpose To examine the changes in length of hospital stay before and after POET publication. Further, to assess safety (relapse of bacteremia and 180 days of mortality) before and after POET publication. Methods By cross-linkage of Danish nationwide registries, patients with first-time IE caused by Streptococcus spp., Enterococcus faecalis, Staphylococcus aureus, or coagulase negative staphylococci from 2012-2021 were identified. Immediately following the publication of the POET trial, the POET criteria was implemented and used in Denmark. The study period was categorized according to publication date (before and after September 2018). Median length of hospital stay was examined according to calendar period. Mortality (from admission date) and relapse of bacteremia (after discharge) at 180 days of follow-up were examined with the Kaplan-Meier estimator and the Cumulative Incidence Function, respectively. Results We identified 3,008 patients before publication of the POET trial (median age 72.8 years) and 1,740 after the publication (median age 75.2 years) (p&amp;lt;0.0001). The burden of comorbidities was comparable between groups. The median length of hospital stay decreased by 8 days: 41 days (IQR: 29-49) before POET publication and 33 days (IQR: 21-44) after POET publication (p&amp;lt;0.0001 for difference), Figure 1. Similar reductions in length of hospital stay were seen across different microbiological etiologies and age groups. The reduction in length of hospital stay was most pronounced in non-surgically treated patients. The mortality from IE admission with a maximum of 180 days follow-up was 27.5% before POET publication and 28.3% after POET publication (p-value=0.41 for difference). The bacteremia relapse rate within 180 days was 3.5% before POET publication and 1.6% after POET publication (p-value=0.0002 for difference), Figure 2. Conclusion Following the POET trial, we found an 8 days reduction in median length of hospital stay with no change in mortality and an associated lower rate of relapse of bacteremia.