Antibiotic Susceptibility Test Results Research Articles

Clinical Situation, Species Distribution, and Antibiotic Resistance of Pathogenic Bacteria and Fungi in 626 Cases of Vulvovaginitis in Hangzhou, China.

Female vulvovaginitis was one of the most common gynecological diseases. It had a great negative impact on their work and quality of life. This retrospective study evaluated the clinical and laboratory data of patients with vulvovaginitis in Hangzhou, China. To analyze the clinical situation, species distribution and antibiotic resistance of pathogenic fungi and bacteria in 626 cases of vulvovaginitis in Hangzhou. Microorganism culture, identification, and antibiotic susceptibility testing were conducted. The study aimed to provide a theoretical value for an effective treatment of vulvovaginitis. In total, 626 outpatients and inpatients diagnosed with vulvovaginitis were selected from January 2018 to January 2023. Data of all the patients were collected from the hospital's electronic medical records. Vaginal secretion was collected for testing and SPSS 25.0 software was used to perform statistical analysis. A total of 626 strains of fungi, Gram-positive, and -negative bacteria were detected. Clinical situations of patients infected with the top five pathogenic fungi and bacteria were analyzed. Pathogenic fungi and bacteria were slightly different in each age group and in each onset time group. The results of antibiotic susceptibility testing showed that the resistance rates of itraconazole and fluconazole were high and Gram- negative and -positive bacteria were multidrug resistant. Gram-negative bacteria were more sensitive to carbenicillins and compound antibiotics, while Gram-positive bacteria were sensitive to rifampicin and daptomycin. MRSA and non vancomycin-resistant strains were detected. Fungi and bacteria were usually detected as pathogenes in patients with vulvovaginitis in Hangzhou. Some factors, such as age and onset time, often affected the incidence. Pathogenic fungi and bacteria were resistant to some common antibiotics, and clinical treatments should be carried out in a timely and reasonable manner according to the results of antibiotic susceptibility testing.

Identification and florfenicol-treatment of pseudomonas putida infection in gilthead seabream (Sparus aurata) fed on tilapia-trash-feed

The present study aimed to determine the major cause of the high mortality affecting farmed gilthead seabream (Sparus aurata) and controlling this disease condition. Fifteen diseased S. aurata were sampled from a private fish farm located at Eldeba Triangle, Damietta, fish showed external skin hemorrhages, and ulceration. Bacterial isolates retrieved from the diseased fish were identified biochemically as Pseudomonas putida and then confirmed by phylogenetic analysis of the 16 S rRNA gene sequence. P. putida was also isolated from three batches of tilapia-trash feed given to S. aurata. Biofilm and hemolytic assay indicated that all P. putida isolates produced biofilm, but 61.11% can haemolyse red blood cells. Based on the antibiotic susceptibility test results, P. putida was sensitive to florfenicol with minimum inhibitory concentrations ranging between 0.25 and 1.0 µg mL− 1, but all isolates were resistant to ampicillin and sulfamethoxazole-trimethoprim. Pathogenicity test revealed that P. putida isolate (recovered from the tilapia-trash feed) was virulent for S. aurata with LD50 equal to 4.67 × 107 colony forming unit (CFU) fish− 1. After intraperitoneal (IP) challenge, fish treated with 10 mg kg− 1 of florfenicol showed 16.7% mortality, while no mortality was recorded for the fish group that received 20 mg kg− 1. The non-treated fish group showed 46.7% mortality after bacterial challenge. HPLC analysis of serum florfenicol levels reached 1.07 and 2.52 µg mL− 1 at the 5th -day post-drug administration in the fish groups received 10 and 20 mg kg− 1, respectively. In conclusion, P. putida was responsible for the high mortality affecting cultured S. aurata, in-feed administration of florfenicol (20 mg kg− 1) effectively protected the challenged fish.

Isolation of aerobic bacteria from abscesses and wounds in rabbits and antibiotic susceptibility testing of Staphylococcus spp. and Pseudomonas spp. isolates

BackgroundWound infections and abscesses in rabbits are a common problem in veterinary practice and their treatment can be challenging. Bacterial culture and antimicrobial susceptibility testing are important tools in these cases. While some studies are available on bacteria associated with wound infections and abscesses in rabbits, the numbers of animals included is generally limited. Monitoring of antibiotic resistance in clinical practice is also an important part of good antibiotic stewardship. Multiple antibiotic resistances are frequently encountered in Staphylococcus and Pseudomonas spp., two groups of bacteria commonly associated with abscesses in rabbits. MethodsThis retrospective study evaluated the results of aerobic bacterial cultures and antibiotic susceptibility tests in swabs from abscesses (A) (n=541) and from skin and wounds (SW) (n=308) submitted to a commercial diagnostic laboratory. Samples submitted between January 2017 and October 2020 were included in the study. Antimicrobial susceptibility testing for Staphylococcus and Pseudomonas spp. was evaluated and compared. ResultsIn A, 465 bacterial isolates including 35 different species were isolated while 394 bacterial isolates, including 35 different species, were found in SW. The most frequently isolated bacteria were Staphylococcus spp. (A = 21.7%, SW = 36.5%) followed by Pasteurella spp. in A (13.3%) and aerobic spore-forming bacteria in SW (11.2%). Pseudomonas spp. was the third most commonly isolated genus in both sample types (A = 11.6%, SW = 8.9%). Pseudomonas aeruginosa isolated from A were more often resistant to the tested antibiotics than other Pseudomonas species. These results support the need for bacterial culture and antibiotic susceptibility testing in small mammal practice.

Characterization of Proteus Spp. And Plasmid Mediated Resistance Among Hospitalized Patients in Eku, Delta State, Nigeria

The study was conducted to analyze the occurrence and antimicrobial susceptibility profile of Proteus species in blood and wound samples from patients who visited Eku General Hospital in Delta State, Nigeria. A total of 60 samples, 30 from blood and 30 from wound, were collected for the study. The bacteria were identified through bacteriological and biochemical analyses, while antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. Plasmid curing was carried out using a sub-inhibitory concentration of 10% sodium dodecyl sulfate on resistant organisms. The study found three isolates including Proteus mirabilis, P. vulgaris, and P. penneri. The results showed that P. mirabilis was the most prevalent in blood (32.3%) and wound (22.6) samples, followed by P. penneri (11.3%), and P. vulgaris (9.7%) in blood sample. The study also found that the highest rate of isolation of the bacterium occurred among individuals aged between 21-35 years, followed by 12-20 years. Result of antibiotic susceptibility test showed high level of resistance in the two most commonly prescribed antibiotics cephalosporins and ampicillin. No resistance was observed in gentamycin making it the best drug for treating empirical infections. However, resistance was mostly carried on plasmids as shown by the loss of resistance after curing by the isolates. Harbouring of resistance on plasmids as huge public health implications including but not limited to spread of resistance genes, as such measures should be put in place to prevent spread.

Antimicrobial susceptibility testing data analysis over 3 years at the Yaoundé General Hospital, Cameroon.

Antimicrobial resistance (AMR) is a major health concern with high rates in low-income countries. Bacteriology laboratories sustain the fight against AMR by providing antibiotic susceptibility testing (AST) results to ensure appropriate therapies. These laboratories generate a lot of data, which are usually used for prospective interventions. Our study conducted in a lower-middle-income hospital setting aimed to describe the profile of bacteria isolated from the specimens received over 3 years, assess their susceptibility profile and identify potential gaps or area of improvement from the analysis of our data. Monthly data were retrieved from registers for all specimens received between January 2020 until December 2022. Data were compiled and analysed using the R and WHONET software. Out of 3582 specimens received, 797 were culture positive (22.3%). Escherichia coli and Klebsiella pneumoniae were frequently isolated (30.5% and 24.2%, respectively). AST results analysis showed high resistance of Gram-negative bacteria to penams and cephems, whereas low resistance was observed to carbapenems. Susceptibility to antibiotics based on the AWaRe antibiotic classification was variable. The bacteriological profile in the various types of specimen was established and rational information to design a therapeutic protocol adapted to our hospital setting was obtained. AST results may not only be used for prospective guidance for treatment, but rather cumulative data analysis can contribute to design effective antibiotic prescriptions and improve general practices at the laboratory. This is, however, dependent on a good record-keeping, standardization of practices and collaboration between clinicians and laboratory scientists.

Clinical characteristics and risk factors for Klebsiella pneumoniae bloodstream infection in 152 immunocompetent patients.

To investigate the clinical characteristics and prognostic risk factors for Klebsiella pneumoniae bloodstream infections in immunocompetent patients. The study included patients with K. pneumoniae bloodstream infection treated in Zhongda Hospital from June 2016 to June 2021. Clinical data and antibiotic susceptibility test results were retrospectively collected and analyzed. Independent risk factors for mortality were screened using the chi-square test and multivariate logistic regression. A total of 152 patients were included in the analysis. In our cohort, 77.6% of patients were older than 60 years, and 80.9% of them had community-acquired infections. The most common complications were type 2 diabetes, hypertension, and stroke sequelae. The proportion of patients with septic shock or abscesses was 34.9% and 25.7%, respectively. There were significant differences in the site of infection, septic shock, and serum levels of procalcitonin, hypersensitive C-reactive protein, D-dimer, creatinine, and lactic acid between survivors and non-survivors (p < 0.05). Multivariate regression analysis showed that hospital-acquired infections, septic shock, length of hospital stay, and creatinine levels were independent risk factors for mortality. Antibiotic susceptibility test results indicated that clinical outcomes varied depending on bacterial sensitivity to ampicillin/sulbactam. Klebsiella pneumoniae is a common community-acquired and hospital-acquired bacteria and usually infects older people with complications such as diabetes. Nosocomial infections, length of stay, septic shock, and renal insufficiency are potentially associated with poor prognosis. Bacterial susceptibility to ampicillin/sulbactam affects prognosis.

Enterococcus faecium BACTERIOCIN EFFLUX PUMP MexA GENE AND PROMOTE SKIN WOUND HEALING IN MICE

The process involved isolating E. faecium from the gut of honeybees, screening the bacterium for bacteriocin-like inhibitory substance (BLIS), evaluating its impact on the expression of the mexA gene in multidrug-resistant (MDR) P. aeruginosa, and determining the role of bacteriocin in treating infected wounds in mice through histopathological examination. After evaluating the best circumstances for producing BLIS, it was discovered that glucose was a superior carbon source and yeast extract was the best source of nitrogen. The pH was found to be 5, the ideal incubation time was 72 hours, and ammonium sulfate salt was used for partial purification at 80% saturation. The identification of MDR P. aeruginosa isolates from pus infections was a further focus of the study. The VITEK 2 system was used to perform the identification. The results of antibiotic susceptibility tests revealed that the greatest resistance rates were found against Meropenem (83.3%) and Gentamicin (73.3%), followed by beta-lactam antibiotics (Ticarcillin, Ticarcillin/Clavulanic Acid, Piperacillin, and Aztreonam), which showed resistance in about 66.6 and 36.6% of the study isolates, respectively. Followed by Imipenem (63.3%), Ceftazidime (36.6%), and Cefepime (36.6%). The mexA gene was detected in all nine strains. The study also investigated the impact of the bacteriocin of the chosen strain on the expression of the mexA gene. An in vivo study revealed that wound healing was enhanced by treating infected wounds with E. faecium bacteriocin. Conclusion: Down-regulation and up-regulation in the expression of the genes following exposure to Bacteriocin indicate the potential of E. faecium as an effective antimicrobial agent against MDR P. aeruginosa infections.

Resistance profile of Escherichia coli isolated from stool, feed, and compost sources to antibiotics in Sukabumi

Antibiotic-resistant E. coli is a growing concern in various settings, but environmental studies are rare compared to clinical research on human and animal health. This study aimed to identify the prevalence of E. coli bacteria resistant to different antibiotics in the environment by examining E. coli resistant to cefotaxime isolated from ruminant stool, feed, and compost. The phenotyping test was conducted through antibiotic susceptibility test using Kirby-Bauer disk-diffusion method, followed by the One-Way variance (ANOVA) analysis of the antibiotic susceptibility test results. Of the 12 isolates exposed to cefotaxime, six showed resistance to this antibiotic, and all isolates, including those resistant to cefotaxime, were resistant to eight out of ten types of antibiotics. All isolates had resistance to at least two to five types of antibiotics. The phenotypic pattern between fecal isolates and non-fecal isolates did not differ significantly, except for the antibiotics amoxicillin (p≤0.05) and ampicillin (p≤0.05). The overlapping resistance patterns observed in animal feed, animal stool, and compost suggest a potential link between their microbiological compositions.

Karbapenem dirençli Gram-negatif mikroorganizmalarda seftazidim-avibaktam duyarlılıklarının değerlendirilmesi

Aims: Carbapenem-resistant Gram-negative microorganisms are gradually increasing in hospitalized patients in intensive care units and causes increased morbidity, mortality, and cost. This study aims to investigate the susceptibility of ceftazidime-avibactam (caz-avi), which has recently started to be used for the treatment of infections caused by carbapenem-resistant (CR) Gram-negative bacteria isolated from various samples received from the intensive care unit (ICU) of our hospital.&#x0D; Methods: Carbapenem-resistant Klebsiella pneumoniae (CRKP) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) strains isolated from various clinical specimens that were sent to our laboratory between January 1st, 2021, and October 30th, 2022, were retrospectively evaluated in the study. The culture and antibiogram results of the samples were received over the laboratory information system (LIS) and evaluated using statistical analyses. Ceftazidime-avibactam susceptibility was studied using the disc diffusion method. &#x0D; Results: Ceftazidime-avibactam antibiotic susceptibility test results of 352 (69.4%) CRKP and 155 (30.6%) CRPA strains isolated from various clinical samples from the ICU of our hospital were analyzed. Of the CRKP strains, 313 (88.9%) were found to be susceptible and 39 (11.1%) were found to be resistant to ceftazidime-avibactam. Of the CRPA strains, 131 (84.5%) were found to be susceptible and 24 (15.5%) were found to be resistant.&#x0D; Conclusion: Determining the regional susceptibility of carbapenem-resistant strains isolated in our hospital to a new antimicrobial combination such as caz-avi will allow a better understanding of the spread of resistance.

Application of Precision Medicine Concepts in Ambulatory Antibiotic Management of Acute Pyelonephritis.

Acute pyelonephritis (APN) is a relatively common community-acquired infection, particularly in women. The early appropriate antibiotic treatment of this potentially life-threatening infection is associated with improved outcomes. The international management guidelines for complicated urinary tract infections and APN recommend using oral antibiotics with <10% resistance among urinary pathogens. However, increasing antibiotic resistance rates among Escherichia coli and other Enterobacterales to fluoroquinolones, trimethoprim-sulfamethoxazole (TMP-SMX), and beta-lactams has left patients without reliable oral antibiotic treatment options for APN. This narrative review proposes using precision medicine concepts to improve empirical antibiotic therapy for APN in ambulatory settings. Whereas resistance rates to a particular antibiotic class may exceed 10% at the population-based level, the predicted antibiotic resistance rates based on patient-specific risk factors fall under 10% in many patients with APN on the individual level. The utilization of clinical tools for the prediction of fluoroquinolones, TMP-SMX, and third-generation cephalosporin resistance improves the ambulatory antibiotic management of APN. It may also reduce the need to switch antibiotic therapy later based on the in vitro antibiotic susceptibility testing results of bacterial isolates in urinary cultures. This approach may mitigate the burden of increasing antibiotic resistance in the community by ensuring that the initial antibiotic prescribed has the highest likelihood of treating APN appropriately.

The Change in Antimicrobial Resistance During the COVID-19 Pandemic in Türkiye

Antimicrobial resistance (AMR) is one of the most important problems threatening human health worldwide. The impact of the Coronavirus disease-2019 (COVID-19) pandemic on AMR continues to be discussed. Some researchers argue that the pandemic will increase AMR rates, while others suggest the opposite. The aim of this study was to investigate the change in AMR of Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus strains in three cross-sectional periods in Türkiye, the first one before the COVID-19 pandemic, the second and the third one during the pandemic. The change in antibiotic susceptibility in Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus strains isolated from urine, blood, and lower respiratory tract samples of patients hospitalized in intensive care units and wards of hospitals before (November 2019) and during the COVID-19 pandemic (November 2020 and July 2021) was investigated in this study. A total of 17 voluntary hospitals, members of the Antibiotic Susceptibility Surveillance Study Group (ADSI) of the Society for Clinical Microbiology Specialists (KLIMUD), participated in the study. Identification of bacteria was performed with automated bacterial identification systems (VITEK2, bioMérieux, France or Phoenix, BD, USA). Antibiotic susceptibility tests were performed in one center with the Kirby-Bauer disc diffusion method and in other centers with automated antibiotic susceptibility test systems (VITEK2, bioMérieux, France or Phoenix, BD, USA), and the results were evaluated according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. Antibiotic susceptibility ratios were statistically analyzed using either the chi-square or Fisher's exact test. A p-value of < 0.05 was considered statistically significant. Antibiotic susceptibility test results of a total of 4030 strains; 1152, 1139, and 1739 belonging to November 2019, November 2020, and July 2021, respectively; were examined. While cefotaxime and ceftazidime susceptibility rates in E.coli strains increased during the pandemic period compared to previous period (p= 0.04, p= 0.001, respectively); nitrofurantoin sensitivity (p= 0.02) and extended-spectrum beta-lactamase (ESBL) ratios (p< 0.001) were found to be decreased. It was determined that the susceptibility rates of all other examined antimicrobials did not change statistically. It was observed that the susceptibility rates of all antibiotics in K.pneumoniae isolates decreased during the pandemic period, but the ESBL rates increased between 2019-2020 (p= 0.01) and decreased between 2020-2021 (p= 0.02). It was found that ESBL rates increased before and after the pandemic. It was observed that the susceptibility to ciprofloxacin (p= 0.0001), levofloxacin (p= 0.003), and gentamicin (p= 0.005) in S.aureus strains increased during the pandemic period. No significant changes were observed in other antibiotic susceptibility rates. Methicillin resistance of S.aureus (MRSA) strains decreased between 2019-2020 (p= 0.03) and increased again in 2021 (p= 0.04) and returned to the pre-pandemic rate. Our study results suggest that the measures taken to reduce the spread of COVID-19 with the pandemic (such as quarantine practices, increased hand hygiene, mask use, and national/international travel restriction) may reduce the spread of bacteria such as ESBL-producing E.coli and the rate of MRSA, which is considered as a hand hygiene indicator. The increase in the later stages of the pandemic recalls the relaxation in compliance with hand hygiene rules. The decrease in the susceptibility rate of K.pneumoniae isolates to antibiotics and the increase in the ESBL rate may be due to inappropriate and excessive use of antibiotics during the pandemic period. However, we believe that these data should be supported by studies to be conducted nowadays when all the rules and measures are back as if the pandemic has ended.

Molecular detection of genes encoding resistance to tetracycline and quinolones among Shigella strains isolated from children with acute diarrhea in southwest Iran.

An increase in the antibiotic resistance of Shigella isolates has caused major global challenges in antimicrobial therapy. Knowledge of local antibiotic resistance trends is essential for selecting appropriate antibiotic treatment regimens. This study aimed to evaluate the frequency of efflux-mediated tetracycline resistance (tet) and plasmid-mediated quinolone resistance (qnr) genes among Shigella isolates. This survey investigated 91 Shigella isolates, obtained from children with acute diarrhea. The isolates were identified using standard biochemical tests and confirmed by polymerase chain reaction (PCR) assay. Besides, the susceptibility of isolates to six selected antibiotics was assessed by the disk diffusion method. All tetracycline-resistant and nalidixic acid and ciprofloxacin resistant strains were screened for tet and qnr genes by a multiplex PCR assay. According to the results of antibiotic susceptibility tests, the highest level of antibiotic resistance was related to tetracycline (80.2%) and doxycycline (78.1%), respectively. All isolates were sensitive to tigecycline. The PCR results showed that 40.6%, 3.1%, 21.8%, 61.6% and 28.7% of the isolates carried qnrA, qnrB, qnrS, tetA, and tetB genes, respectively. None of the isolates contained tetC and tetD genes. The current findings revealed that tetA and qnrA genes might play a key role in conferring tetracycline and quinolone resistance.

Rapid detection of viable Acinetobacter baumannii and antibiotic susceptibility testing based on a phage amplification-Taqman qPCR assay

BackgroundTimely and accurate identification of pathogenic bacteria and antibiotic susceptibility could decrease misuse and overuse of antibiotics. In this study, we developed a phage amplification-Taqman qPCR assay for simultaneous viable Acinetobacter baumannii (A. baumannii) detection and determination of broad-spectrum antimicrobial susceptibility based on quantification of phage DNA replication in one single tube. ResultsThe two-phage cocktail used in the current phage amplification-Taqman qPCR assay consists of phage p53 and phage pB3074. Once a lytic phage infects its host, phages could specifically recognize the viable cells and replicate themselves within the cells to produce hundreds of progeny phages. With dual phage cocktail concentration (5.00 × 103 PFU/mL to 5.00 × 104PFU/mL) used, down to 50 CFU /mL of viable A. baumannii could be detected within 3 h from bronchoalveolar lavage fluid spiked with A. baumannii in an incubation volume of 2 mL. We further illustrated that antibiotic susceptibility testing results could be obtained within 2 h based on current phage amplification-Taqman qPCR assay to measure the phenotypic response of A. baumannii from spiked bronchoalveolar lavage fluid after only 30 min of antibiotic exposure. Testing of 12 bronchoalveolar lavage fluid samples spiked by different strains showed that the phage amplification-Taqman qPCR assay had 100 % (95 %CI: 74.12 to 100) identification agreement with the initial spiked concentrations of the bacteria. Subsequent antibiotic susceptibility testing results of 9 bronchoalveolar lavage fluid samples spiked by different strains also had shown that the phage amplification-Taqman qPCR assay had good agreements with the standard broth microdilution method, with an overall agreement of 100 % (95 % CI, 70.09 to 100) for ceftazidime and aztreonam. Significance and NoveltyDue to the high rapidity, high sensitivity, good specificity, low cost, and the ability to distinguish between live and dead bacteria, the phage amplification-Taqman qPCR assay provides an effective and promising strategy for the simultaneous detection of viable bacteria and determination of broad-spectrum antimicrobial susceptibility.

Biofilm Formation of Locales Clinical Multidrug Resistance Klebsiella pneumoniae Isolated from Different Sources deals with Antimicrobial Resistance

The goal of this study was to detect antibiotic resistance and determine the ability of clinical isolates Klebsiella pneumoniae (K. pneumoniae) to form biofilms and detect the relationship between biofilm formation and antimicrobial resistance that depends on the specimen sources at the localized Baghdad Hospitals. This gram-negative rod bacterium is an opportunistic pathogen that can cause various illnesses in people and animals, such as important respiratory tract infections. For these reasons, our study included 87 isolates of K. pneumoniae from different clinical cases. The number and percentage of obtained isolates according to the sources distributed as specimens: 26(29.9%) urine, 25(28.7%) blood, 8(9.2%) stool, and 4(4.6%) sputum, as well as swabs:11(12.6%) burn, 9(10.3%) vagina and 4(4.6%) wound. The antibiotic susceptibility test results showed colistin, Imipenem, and meropenem were more effective against the isolates. The tissue culture plate and Congo red methods were used to evaluate biofilm formation. Finally, polymerase chain reaction was used to identify two genes linked with biofilm formation: MrkD and FimH. The isolates showed different abilities to produce biofilms based on clinical sources. The result appeared (97.7%) of isolates as biofilm producers from the following: 41(47.13%) strongly, 33 (37.93%) moderately, and 11 (12.64%) weakly. While only two isolates 2 (2.3 %) represented non-biofilm producers. 100 and 91% of the isolates, respectively, had the MrkD and FimH biofilm formation genes, according to molecular analysis. A recent study showed biofilm formation by K. pneumoniae strains isolated from blood specimens could form stronger biofilms. On the other hand, stool specimens formed weaker biofilm compared to them. According to this study, multidrug-resistant (MDR) K. pneumoniae strains' capacity to form biofilms and their antibiotic resistance profile is positively correlated. These could aid in developing therapeutic therapies for infections brought on by K. pneumoniae resistant to carbapenems, considered the "final line of defense" antibiotics. We can infer from this work that K. pneumoniae could be isolated from many sources and was MDR, as well as having the different capacity to build biofilm in various ways, especially in hospital cases of high antibiotic resistance. Keywords: K. pneumoniae, Biofilm formation, MDR, PDR, XDR, Congo red

Analysis of Pathogenic Bacterial Spectrum, Drug Resistance and Risk Factors for Mortality of Bloodstream Infection in Patients with Hematologic Diseases

To analyze the pathogenic bacterial spectrum, drug resistance, and risk factors associated with multidrug-resistant bacterial infection and mortality in patients with hematologic diseases complicated by bloodstream infections, so as to provide reference for rational drug use and improving prognosis. Positive blood culture specimens of patients with hematologic diseases in two Class A tertiary hospitals of Shanxi province from January 2019 to December 2021 were retrospectively analyzed. Pathogen distribution, drug resistance and outcomes of patients with bloodstream infection were investigated, then the multivariate logistic analysis was performed to analyze the risk factors of multidrug-resistant bacterial infection and factors affecting prognosis. 203 strains of pathogens were identified, mainly Gram-negative bacteria (GNB) (69.46%, 141/203), of which Escherichia coli (E.coli) had the highest incidence (41.13%, 58/141), followed by Klebsiella pneumoniae (20.57%, 29/141) and Pseudomonas aeruginosa (12.77%, 18/141). Extended-spectrum beta-lactamase (ESBL)-producing E.coli and Klebsiella pneumoniae were 46.55% (27/58) and 37.93% (11/29), respectively. Carbapenem-resistant Gram-negative bacteria accounted for 10.64% (15/141). And Gram-positive bacteria accounted for 27.59% (56/203), Staphylococcus epidermidis, Streptococcus pneumoniae, and Staphylococcus aureus were the most frequently isolated pathogen among Gram-positive bacteria (14.29%, 12.50% and 10.71%, respectively), of which methicillin-resistant Staphylococcus aureus accounted for 33.33% (2/6), coagulase-negative staphylococci accounted for 87.50% (7/8), without vancomycin- or linezolid-resistant strain. Additionally, fungi accounted for 2.95% (6/203), all of which were Candida. Multidrug-resistant Gram-negative bacteria (MDR-GNB) accounted for 53.90% (76/141). Duration of neutropenia >14 days was a risk factor for developing MDR-GNB infection. The 30-day all-cause mortality was 10.84%. Multivariate logistic regression analysis showed that the significant independent risk factors for mortality were age≥60 years (P <0.01, OR =5.85, 95% CI: 1.80-19.07) and use of vasopressor drugs (P <0.01, OR =5.89, 95% CI: 1.83-18.94). The pathogenic bacteria of bloodstream infection in patients with hematological diseases are widely distributed, and the detection rate of multidrug-resistant bacteria is high. The clinicians should choose suitable antibiotics according to the results of bacterial culture and antibiotic susceptibility test.

National public health response to an outbreak of toxigenic Corynebacterium diphtheriae among asylum seekers in England, 2022: a descriptive epidemiological study

In July, 2022, an increase in diphtheria cases caused by toxigenic Corynebacterium diphtheriae (C diphtheriae) was reported among asylum seekers arriving by small boats to England. Rising case numbers presented challenges for case and contact management in initial reception centres, prompting changes to national guidance and implementation of population-based control measures. This study aimed to describe the outbreak of toxigenic C diphtheriae among asylum seekers arriving by small boats to England during 2022 by use of national surveillance data. We undertook a descriptive epidemiological analysis of cases of toxigenic C diphtheriae among asylum seekers arriving by small boats to England during 2022, incorporating genomic sequencing data, antibiotic susceptibility testing results, and epidemiological data obtained through the UK Health Security Agency's national enhanced surveillance programme. Health Protection Teams conducted risk assessments, and operational data (including details regarding offer and uptake of antibiotics and vaccinations) were obtained from National Health Service partners supporting the intervention programme. In 2022, C diphtheriae isolates from 86 asylum seekers arriving by small boats were submitted to the National Reference Laboratory for confirmation and testing. Toxigenic C diphtheriae was confirmed for 72 (84%) cases and one individual with typical diphtheritic lesions but from whom no C diphtheriae was isolated from clinical swabs was also included as a probable case, resulting in 73 cases of diphtheria. 71 (97%) were male, 39 (53%) were younger than 18 years, and 36 (49%) presented with cutaneous diphtheria. The prevalence of diphtheria was highest among Afghans (1·3%) compared with all other nationalities (<0·1%). Local antibiotic susceptibility testing identified six cases with a macrolide resistant strain. The increase in diphtheria coincided with a high volume of asylum seekers arriving by small boats to England during 2022, and subsequently increased clinical awareness of the disease among this population. Long-term disruption to vaccination programmes in origin countries along with barriers to accessing health care along migrant routes puts asylum seekers arriving by small boats at risk of disease. With arrivals expected to continue in 2023, the UK Health Security Agency has recommended continuation of population-based control measures in England until October, 2023, subject to ongoing review. The UK Health Security Agency.

Surgical rescue strategies and techniques for severe intra-abdominal infection

Severe intra-abdominal infection is complicated with sepsis or septic shock and could also be named as intra-abdominal sepsis. Surgical rescue is an effective intervention for severe intra-abdominal infection, which can be caused by surgery, trauma or acute abdomen. Institutional factors associated with failure of surgical rescue include hospital volume, technology, surgeons and nurses. Patient factors contributing to failure include advanced age, diabetes mellitus and chronic organ dysfunction. The surgical rescue strategy for severe intra-abdominal infection includes damage control surgery and damage control resuscitation. Stepwise escalated procedures based on the severity of the infections should be performed as soon as possible to control the infection source, including removal of catheter in blood vessel, change of intra-abdominal drainage, trochar-assisted percutaneous abscess drainage (TA-PAD), laparotomy and open abdomen therapy. Since most of the pathogenic microorganisms of severe abdominal infections are multi-drug resistant bacteria expressing Klebsiella pneumoniae carbapenemase (KPC), the choice of empirical antibiotics can be guided by rapid identification of the KPC type before the results of antibiotic susceptibility testing are available, namely the antibiotic selection strategy of "enzyme first, then bacteria".

Rapid Detection of blaKPC in Carbapenem-Resistant Enterobacterales Based on CRISPR/Cas13a

Klebsiella pneumoniae carbapenemase (KPC) is a crucial enzyme that causes carbapenem resistance in Enterobacterales, and infections by these "superbugs" are extremely challenging to treat. Therefore, there is a pressing need for a rapid and accurate KPC detection test to control the prevalence of carbapenem-resistant Enterobacterales (CREs). In this study, we established a novel method for detection of blaKPC, the gene responsible for encoding KPC, based on a recombinase polymerase amplification (RPA) and a CRISPR/Cas13a reaction coupled to fluorophore activation (termed RPA-Cas13a assay). We carefully selected a pair of optimal amplification primers for blaKPC and achieved a lower limit of detection of approximately 2.5 copies/μL by repeatedly amplifying a recombinant plasmid containing blaKPC. The RPA-Cas13a assay demonstrated a sensitivity of 96.5% and specificity of 100% when tested on 57 blaKPC-positive CRE strains, which were confirmed by DNA sequencing. Moreover, in 311 sputum samples, the theoretical antibiotic resistance characteristics of blaKPC-positive strains obtained by the RPA-Cas13a assay were highly consistent with the results of antibiotic susceptibility test (Kappa = 0.978 > 0.81, P < 0.01). In conclusion, the RPA-Cas13a system is a simple and one-hour efficient technology for the detection of a potentially fatal antibiotic resistance gene.

Causative microbes and antibiotic susceptibility of acute appendicitis in adults and children

In recent years, some studies have found that acute uncomplicated appendicitis can be treated with antibiotics alone. Because of the lack of relevant research on treating acute appendicitis in Taiwan, this study investigated the microbiological characteristics of acute appendicitis to permit accurate empirical antibiotic use for uncomplicated appendicitis. In this single-center retrospective cohort study, patients listed in the Taiwan National Health Insurance Research Database with a discharge diagnosis of acute appendicitis were identified. Data for bacterial specimens and antibiotic susceptibility tests among patients treated at Tri-Service General Hospital between January 2016 and December 2021 were analyzed. Among 2805 patients diagnosed with acute appendicitis, 167 (6%) were <18 years old. The culture positivity rates among children and adults were 33% and 18%, respectively. In total, 367 aerobes and 207 anaerobes were isolated. The predominant aerobic gram-positive coccus was viridans group streptococci (8.9%), the most common aerobic gram-negative bacillus was Escherichia coli (27.9%), and the most common anaerobic microorganism was Bacteroides spp. (27.7%). The results of antibiotic susceptibility testing of the predominant microorganisms revealed that 86.3% of gram-positive aerobes were susceptible to ampicillin, 76.3% of gram-negative aerobes were susceptible to gentamicin, and all anaerobic isolates were susceptible to metronidazole. Triple first-line antibiotic combination therapy, including ampicillin, gentamicin, and metronidazole, remains highly effective against the pathogens that cause acute appendicitis.

A case of meningitis caused by Ralstonia insidiosa, a rare opportunistic pathogen

BackgroundRalstonia is a genus of Gram-negative opportunistic bacteria that can survive in many kinds of solutions and cause a variety of infections. Ralstonia spp. have increasingly been isolated and reported to cause infections in recent years, thanks to the development of identification methods such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and gene sequencing. However, infections caused by Ralstonia insidiosa are still rare. Only a few cases of respiratory infections and bloodstream infections have been reported, none of which involved meningitis. To the best of our knowledge, this is the first reported case of meningitis caused by R. insidiosa worldwide. It is necessary to report and review this case.Case presentationWe report a case of meningitis caused by R. insidiosa following lumbar surgery in China. The patient exhibited symptoms of headache, dizziness, and recurrent fever. The fever remained unresolved after empiric antibiotic therapy with intravenous cefotaxime and vancomycin in the initial days. Cerebrospinal fluid (CSF) culture yielded Gram-negative non-fermentative bacteria, which were identified as R. insidiosa. As there was a lack of antibiotic susceptibility testing results, clinical pharmacists conducted a literature review to select appropriate antibiotics. The patient’s condition improved after receiving effective treatment with intravenous cefepime and levofloxacin.ConclusionsUncommon pathogens, such as R. insidiosa, should be considered in postoperative central nervous system (CNS) infections, particularly in cases with unsatisfactory results of empiric anti-infective therapy. This is the first reported case of meningitis caused by R. insidiosa worldwide. MALDI-TOF MS provides rapid and accurate identification of this pathogen. The antibiotic susceptibility testing results of R. indiosa may be interpreted based on the breakpoints for Pseudomonas spp., Burkholderia cepacia spp., and Acinetobacter spp. Our case presents a potential option for empiric therapy against this pathogen, at least in the local area. This is crucial to minimize the severity and mortality rates associated with meningitis. Standardized antibiotic susceptibility testing and breakpoints for the Ralstonia genus should be established in the future as cases accumulate. Cefepime and levofloxacin may be potential antibiotics for infections caused by R. indiosa.