Positive Culture Results Research Articles

Clinical characteristics of 11 patients with Vibrio vulnificus infection and the establishment of a rapid diagnosis procedure for this disease

Clinical characteristics of 11 patients with Vibrio vulnificus infection and the establishment of a rapid diagnosis procedure for this disease

Kidney damage relates to agonal bacteremia: a single-center retrospective study.

Agonal bacteremia, diagnosed with postmortem positive blood culture results, is considered a possible contributing factor to death. We hypothesized that some premortem organ damage, such as kidney damage, can enhance agonal bacteremia. We performed a postmortem blood and alveolar fluid culture study in 30 cadavers and evaluated the relationship between blood culture results and clinical parameters, including organ damage (brain, heart, lung, kidney, liver and gastrointestinal tract). A total of 23 cases (76.7%) were positive for blood culture; the number of cultured species was one in 12 cases, two in 7 cases, and three in 4 cases. The ratio of agonal bacteremia was significantly higher in patients with heart damage (100%, n=13) and those with kidney damage (end-stage kidney damage, acute kidney injury, obstructive kidney failure, or metastatic kidney tumours) (100%, n=13). The mean number of cultured species was 0.67±0.98 in heart or kidney damage, 1.40±0.55 in heart damage only, 1.40±0.55 in kidney damage only, and 2.00±0.93 in heart and kidney damage. As the number of damaged organs increased (0 organs, no heart/kidney damage; 1 organ, heart or kidney damage; and 2 organs, heart and kidney damage), the mean number of cultured species increased significantly (p for trend=0.001964). Premortem kidney damage relates to agonal bacteremia.

Joint Fluid Cell Count in Acute Bacterial Arthritis Patients Proven Positive Culture in Children.

Acute bacterial arthritis (ABA) is a serious, pediatric infection that can result in motor comorbidities. Normally, a joint fluid white blood cell (WBC) count of 50,000 or more cells/mm 3 is used to make a presumptive diagnosis of ABA. This study evaluated the utility of the joint fluid WBC count for diagnosing pediatric ABA confirmed by a positive culture result. Patients with ABA between March 2010 and March 2023 at Tokyo Metropolitan Children's Medical Center were included. ABA was confirmed by positive joint fluid culture results for a pathogenic organism. Patients with negative results and those without a joint fluid WBC count were excluded. Electronic medical records were retrospectively reviewed for demographic data, timing of arthrocentesis, culture results and the joint fluid WBC count. Ninety-five patients with ABA were identified; of these, 22 were included. The median age was 5 years [interquartile range (IQR): 2-10 years]. Males comprised 55% of the population. The median joint fluid WBC count was 19,575 (IQR: 6806-47,388) cells/mm 3 , and 23% of the patients had 50,000 cells/mm 3 or more. The median time from symptom onset to arthrocentesis was 3 days (IQR: 2-5 days). The isolated organisms were methicillin-susceptible Staphylococcus aureus (50%), methicillin-resistant S. aureus (9%), Streptococcus pyogenes (27%), Streptococcus pneumoniae (5%), Klebsiella pneumoniae (5%) and Salmonella spp. (5%). Most of the patients with ABA confirmed by positive results of a joint fluid culture had a joint fluid WBC count of less than 50,000 cells/mm 3 .

The False-Positive Rate of Synovial Fluid Culture at a Single Clinical Laboratory Using Culture Bottles.

Introduction Synovial fluid (SF) cultures can yield false-positive or negative results when diagnosing periprosthetic joint infection (PJI). False-positives may arise during sample collection or from laboratory contamination. Understanding false-positive SF culture rates is crucial for interpreting PJI laboratory data, yet clinical laboratories rarely report these rates. This study aimed to define the false-positive SF culture rate at a major specialized clinical laboratory. Methods This study retrospectively analyzed prospectively collected data at a single clinical laboratory that receives SF for clinical testing for PJI. A total of 180,317 periprosthetic SF samples from the hip, knee, and shoulder were identified from January 2016 to December 2023, which met the inclusion criteria for this study. Samples were classified by both a modified 2018 International Consensus Meeting (ICM) score and an inflammation score that combined the SF-C-reactive protein, alpha-defensin, SF-white blood cell count, and SF-polymorphonuclear% into one standardized metric. Logistic regression was utilized to evaluate the impact of various collection-based characteristics on culture positivity, including inflammation biomarkers, the source joint, quality control metrics, and days of specimen transport to the laboratory. SF culture false-positivity was calculated based on the ICM category of "not-infected" or low inflammation score. Results Overall, 13.3% (23,974/180,317) of the samples were associated with a positive culture result: 12.5% for knee samples, 20.3% for hip samples, and 14.7% for shoulder samples. The false-positive SF culture rate among 131,949 samples classified as "not-infected" by the modified 2018 ICM definition was 0.47% (95%CI: 0.43 to 0.51%). Stratification by joint revealed a false-positive rate of 0.34% (95%CI: 0.31 to 0.38%) for knee samples, 1.24% (95%CI: 1.05 to 1.45%) for hip samples, and 3.02% (95%CI: 2.40 to 3.80%) for shoulder samples, with p < 0.0001 for all comparisons. The false-positive SF culture rate among 90,156 samples, representing half of all samples with the lowest standardized inflammation scores, was 0.47% (95%CI: 0.43 to 0.52%). Stratification by joint revealed a false-positive rate of 0.33% (95%CI: 0.29 to 0.37%) for knee samples, 1.45% (95%CI: 1.19 to 1.77%) for hip samples, and 3.09% (95%CI: 2.41 to 3.95%) for shoulder samples, with p<0.0001 for all comparisons. Multivariate logistic regression demonstrated the joint source (hip, shoulder) and poor sample quality as collection-based factors associated with a false-positive culture. Evaluation of a cohort of samples selected to minimize collection-based causes of false-positive culture demonstrated a false-positive rate of 0.30%, representing the ceiling limit for laboratory-based SF culture false-positivity. Conclusions This study utilizes two methods to estimate the false-positive SF culture rate at a single specialized clinical laboratory, demonstrating an overall false-positive rate of approximately 0.5%. Stratification of samples by source joint demonstrated that periprosthetic SF from the shoulder and hip have a substantially higher false-positive culture rate than that of the knee. The lowest false-positive SF culture rate (0.30%) was observed among samples from the knee-passing quality control. Culture positivity due to contamination at this specific laboratory is less than 0.30% because all specimens undergo identical processing.

The molecular detection of carbapenem markers with a two-levels amplification screening protocol: epidemiological and resistome insights.

Carbapenem-resistance is a challenging healthcare concern and require specific stewardship programs. Monitoring workflows include the identification from surveillance samples, such as rectal swabs. Although culture assays represent the gold standard, data report a significant effectiveness in detecting carbapenemases genes directly from rectal swabs. The aim of this study was to evaluate the REALQUALITY Carba-Screen kit (AB ANALITICA, Padova, Italy) in detecting carbapenemases genes directly from rectal swabs, also comparing its effectiveness to culture assays results. A next-generation sequencing (NGS) was performed to investigate the positive samples about resistance markers and sequence type (ST). A number of 136 rectal swabs were collected from the University Hospital Policlinico of Catania critical wards. The samples simultaneously underwent culture and molecular assays (REALQUALITY Carba-Screen kit). The molecular method included two-steps. The first step (1 h and 6 min) rapidly excluded negative samples, while the second one (1 h and 6 min) included only positive samples for a resistance confirmation. All the positive culture samples underwent NGS analysis. Statistical evaluations demonstrated high sensitivity (100%) and detection rates (92.6%) for the REALQUALITY Carba-Screen kit, which mostly correlated to the standard workflow. All the culture positive results matched the positive molecular results, which were mainly confirmed by the NGS resistome analysis. The identified ST appeared to be diversified and different from the clinically significative strains of the same setting, furnishing interesting epidemiological evidence. The molecular detection allowed a coordinate approach in a high-prevalence multi-drug-resistance area. The rapid identification with a multi-step procedure accelerated the infection control procedures, while the preliminary negative results reduced the overtreatment episodes. The molecular method efficacy was confirmed through the NGS. In conclusion, the molecular screening could initially lead to a more conservative approach, which may be reevaluated after a culture result about the microorganisms' identification and susceptibility profile.

The prevalence and clinical context of antimicrobial resistance amongst medical inpatients at a referral hospital in Rwanda: a cohort study

BackgroundAntimicrobial resistance (AMR) is a growing global concern. AMR surveillance is a crucial component of the international response; however, passive surveillance of laboratory data is limited without corresponding patient-level clinical data. This study sought to examine the burden of AMR amongst medical inpatients in Rwanda, in the context of their clinical presentations and prior antibiotic exposures.MethodsThis cohort study was conducted over a 9-month period at a tertiary referral hospital in Kigali, Rwanda. We enrolled 122 adult medical inpatients with a history of fever and a positive microbiological culture result. Data were collected regarding the clinical and microbiological aspects of their admission.ResultsThe most common diagnoses were urinary tract infection (n = 36, 30%), followed by pneumonia (n = 30, 25%) and bacteraemia (11 primary [9%] and 10 catheter-related [8%]). The most common pathogens were E. coli (n = 40, 33%) and Klebsiella pneumoniae (n = 36, 30%). The cohort were heavily antibiotic-exposed at the time of culture with 98% of patients (n = 119) having received an antibiotic prior to culture, with a median exposure of 3 days (IQR 2–4 days). Eighty patients (66%) were specifically prescribed ceftriaxone at the time of culture. Gram-negative organisms predominated (82% [100/122]) and exhibited high rates of resistance, with only 27% (21/77) being susceptible to ceftriaxone, 2.4% (2/82) susceptible to co-amoxiclav and 44% (8/18) susceptible to ciprofloxacin. Susceptibility amongst Gram-negatives was relatively preserved to amikacin (91%, 79/87) and imipenem (85%, 70/82). There were no cases of methicillin-resistant Staphylococcus aureus (0/12) or vancomycin-resistant enterococci (0/2). Discordant antibiotic therapy was significantly associated with in-hospital mortality (OR 6.87, 95%CI 1.80–45.1, p = 0.014).ConclusionsThis cohort highlights high rates of resistance amongst Gram-negative organisms in Rwanda, including the presence of carbapenem resistance. Nonetheless, the detailed prescribing data also highlight the challenges of using routine laboratory data to infer broader AMR prevalence. The significant exposure to empiric broad-spectrum antibiotic therapy prior to culturing introduces a selection bias and risks over-estimating the burden of resistant organisms. Broadening access to microbiological services and active surveillance outside of teaching hospitals are essential to support national and international efforts to curb the growth of AMR in low-resource settings.

Microbiologic Profile of Nipple Swab Culture and its Association With Postoperative Complications in Prosthetic Breast Reconstruction.

In breast surgeries, a lactiferous duct leading to lactic glands of breast parenchyma allows direct contamination by normal bacterial flora of the nipple-areola complex. Complete blockage of nipple flora from the intraoperative field is almost impossible. We aimed to analyze the microbiological profile of nipple flora of breast cancer patients who underwent an implant-based immediate breast reconstruction after a total mastectomy, and to evaluate the association of nipple bacterial flora with postoperative complications. A retrospective chart review was performed of patients who underwent an implant-based immediate breast reconstruction after a total mastectomy. A nipple swab culture was performed preoperatively. Patient demographics, surgical characteristics, and complications were compared between positive and negative nipple swab culture groups. Microbiological profile data including antibacterial resistance were collected. Among 128 breasts, 60 cases (46.9%) had positive preoperative nipple swab culture results. Staphylococcus epidermidis accounted for 41.4% of microorganisms isolated. A multivariate logistic regression analysis of postoperative complications revealed that the presence of nipple bacterial flora was a risk factor for capsular contracture. Seven cases of postoperative infection were analyzed. In 2 cases (40% of pathogen-proven infection), the causative pathogen matched the patient's nipple bacterial flora, which was methicillin-resistant S. epidermidis in both cases. Nipple bacterial flora was associated with an increased risk of capsular contracture. Preoperative analysis of nipple bacterial flora can be an informative source for treating clinically diagnosed postoperative infections. More studies are needed to determine the effectiveness of active antibiotic decolonization of the nipple.

Risk factors, outcomes, and epidemiological and etiological study of hospitalized COVID-19 patients with bacterial co-infection and secondary infections

BackgroundAs a common complication of viral respiratory tract infection, bacterial infection was associated with higher mortality and morbidity. Determining the prevalence, culprit pathogens, outcomes, and risk factors of co-infection and secondary infection occurring in hospitalized patients with coronavirus disease 2019 (COVID-19) will be beneficial for better antibiotic management.MethodsIn this retrospective cohort research, we assessed clinical characteristics, laboratory parameters, microbiologic results, and outcomes of laboratory-confirmed COVID-19 patients with bacterial co-infection and secondary infection in West China Hospital from 2022 December 2nd to 2023 March 15th.ResultsThe incidence of bacterial co-infection and secondary infection, as defined by positive culture results of clinical specimens, was 16.3% (178/1091) and 10.1% (110/1091) respectively among 1091 patients. Acinetobacter, Klebsiella, and Pseudomonas were the most commonly identified bacteria in respiratory tract samples of COVID-19 patients. In-hospital mortality of COVID-19 patients with co-infection (17.4% vs 9.5%, p = 0.003) and secondary infection (28.2% vs 9.5%, p < 0.001) greatly exceeded that of COVID-19 patients without bacterial infection. Cardiovascular disease (1.847 (1.202–2.837), p = 0.005), severe COVID-19 (1.694 (1.033–2.778), p = 0.037), and critical COVID-19 (2.220 (1.196–4.121), p = 0.012) were proved to be risk factors for bacterial co-infection, while only critical COVID-19 (1.847 (1.202–2.837), p = 0.005) was closely related to secondary infection.ConclusionsBacterial co-infection and secondary infection could aggravate the disease severity and worsen clinical outcomes of COVID-19 patients. Notably, only critical COVID-19 subtype was proved to be an independent risk factor for both co-infection and secondary infection. Therefore, standard empirical antibiotics was recommended for critically ill COVID-19 rather than all the inpatients according to our research.

Success of different therapies for bacterial endometritis in stud farm practice

Bacterial endometritis is a major problem in equine reproduction usually treated with antibiotics, however reports of success rates are scarce. This study collected data from mares diagnosed with intrauterine bacterial growth and compared the outcome of different therapies for bacterial endometritis in German stud farm practice. Data on mares with positive uterine culture results were collected retrospectively in veterinary practices (n = 5; 2018-2022). Information relating to 30 factors (mare, diagnostics, therapy, pregnancy rate) of bacterial endometritis cases (n = 772) were recorded and analyzed. Possible effects on treatment success (positive pregnancy result in the first cycle after treatment) were tested by binomial logistic regression. In most cases β-hemolytic streptococci were detected (n = 707). Treatments for the endometritis included trimethoprim-sulfonamides (n = 409), procaine-penicillin (n = 227), marbofloxacin (n = 53) or no antibiotics (n = 59) and most antibiotics were administered systemically (n = 711) rather than locally (n = 23). Uterine lavage was reported in 49 % of mares. Uterotonic drugs were administered in 42.2 % of mares. Breeding programs included artificial insemination (AI) with chilled semen (n = 667), AI with frozen semen (n = 169), transfer of fresh (n = 112) or cryopreserved (n = 27) embryos and natural cover (n = 27). In the first cycle after treatment, the pregnancy rate was 47 % and it rose to 69 % by end of the season. Treatment success was affected by duration of antibiotic treatment, veterinary practice, and presence of clinical signs. In conclusion, reported treatment practices in German stud farm practice resulted in acceptable pregnancy results and the multiple binomial logistic regression approach identified factors affecting the pregnancy outcome in this dataset.

Persistently High Procalcitonin and C-Reactive Protein Are Good Predictors of Infection in Acute Necrotizing Pancreatitis: A Systematic Review and Meta-Analysis.

Infected necrotizing pancreatitis (INP) is associated with an increased risk of organ failure and mortality. Its early recognition and timely initiation of antibiotic therapy can save patients' lives. We systematically searched three databases on 27 October 2022. In the eligible studies, the presence of infection in necrotizing pancreatitis was confirmed via a reference test, which involved either the identification of gas within the necrotic collection through computed tomography imaging or the examination of collected samples, which yielded positive results in Gram staining or culture. Laboratory biomarkers compared between sterile necrotizing pancreatitis and INP were used as the index test, and our outcome measures included sensitivity, specificity, the receiver operating characteristic (ROC) curve and area under the ROC curve (AUC). Within the first 72 hours (h) after admission, the AUC of C-reactive protein (CRP) was 0.69 (confidence interval (CI): 0.62-0.76), for procalcitonin (PCT), it was 0.69 (CI: 0.60-0.78), and for white blood cell count, it was 0.61 (CI: 0.47-0.75). After the first 72 h, the pooled AUC of CRP showed an elevated level of 0.88 (CI: 0.75-1.00), and for PCT, it was 0.86 (CI: 0.60-1.11). The predictive value of CRP and PCT for infection is poor within 72 h after hospital admission but seems good after the first 72 h. Based on these results, infection is likely in case of persistently high CRP and PCT, and antibiotic initiation may be recommended.

Continual Improvement in Clinical Bacteriology Laboratory with Quality Indicators: A Retrospective Observational Study

Introduction: Healthcare management is undergoing significant changes with the evolution of new and re-emerging infections. A clinical microbiologist plays an important role in giving an accurate and timely report to the clinicians. Quality Indicators (QIs) act as a measure of the quality of services offered by the laboratory and are tools to monitor and evaluate the laboratory’s performance throughout the Total Testing Process (TTP). Aim: To measure the performance of the clinical bacteriology laboratory using QIs. Materials and Methods: A retrospective study was conducted in the Department of Microbiology at Lokmanya Tilak Municipal Medical College and General Hospital, Mumbai, Maharashtra, India. The study evaluated QIs from the records of 94,624 samples received in the bacteriology section of the clinical Microbiology laboratory between January 2018 and March 2021. Data analysis was conducted over a six-month period from December 2021 to May 2022. In 2018, one QI was identified for each phase, with an additional QI added in each phase to the pre-existing QI in 2019. In 2020, a QI was added in the preanalytical phase only. In 2021, the acceptable limit for one preanalytical QI was reduced from 2% to 1%. Data analysis was performed using an Excel sheet. Results: Data from records of 94,624 clinical bacteriology samples collected over 39 months were analyzed retrospectively. The preanalytical indicators included the number of samples rejected (135, 0.14%) and the number of requisition forms with three patient identifiers (59,645, 93.95%). Analytical phase QIs consisted of the average External Quality Assurance Scheme (EQAS) performance score (97.44% from January 2018 to March 2021) and outliers in the Internal Quality Control (IQC) (25 from January 2019 till March 2021). Failures in the IQC were not assessed in 2018. Postanalytical phase QIs included Turnaround Time (TAT) (average of 2.55 days for aerobic growth) and reporting time for critical alerts, which was within 24 hours of alert finding (100% for smear and culture-positive results). Conclusion: Regular monitoring of QIs helps to identify potential errors. This laboratory chose to analyse and monitor its processes using practically feasible QIs. It was found that the laboratory consistently maintained its performance throughout the study period.

Prevalence of Methicillin Resistant Staphylococcus aureus Colonisation in Patients undergoing Total Joint Arthroplasty: A Retrospective Observational Study

Introduction: Methicillin Resistant Staphylococcus aureus (MRSA) presents a significant, yet preventable, complication in Total Joint Arthroplasties (TJAs). Surgical Site Infections (SSIs) of prosthetic joints resulting from MRSA lead to substantial patient morbidity, mortality, and impose a significant burden on healthcare budgets. One method to mitigate these risks is to screen for MRSA colonisation prior to elective surgeries. The prevalence of MRSA colonisation in nasal mucosa ranges from 0.18-7.2% in different patient populations, with a nosocomial prevalence of 1.7%. Aim: To determine the prevalence of MRSA colonisation in all patients undergoing elective TJA, including Total Hip Replacement (THR) or Total Knee Replacement (TKR). Materials and Methods: A retrospective observational study was conducted on a total of 407 patients scheduled for elective TJAs. Data from 407 patients who underwent elective TJA between January 2020 and December 2022 (a period of three years) were selected for the study. Data compilation and analysis of the study subjects were performed retrospectively until March 2023 at the Sanjay Gandhi Institute of Trauma and Orthopaedics, a tertiary care Orthopaedic centre in Bengaluru, Karnataka, India. The study subjects were screened for MRSA colonisation through nasal swab culture and sensitivity. Patients with positive MRSA culture results were treated with decolonisation therapy, which involved the local application of 2% mupirocin and chlorhexidine body wash for five days. Descriptive data analytics were employed in the study, and tables were generated using Microsoft Word 2010 and Microsoft Excel 2010 (Microsoft Corp, Redmond, WA, USA). Results: The prevalence rates of MRSA nasal colonisation were n1=8 (8.42%), n2=2 (2%), and n3=16 (7.55%) for the years 2020 (n1), 2021 (n2), and 2022 (n3), respectively, at the centre. The period prevalence rate of MRSA colonisation in the nasal mucosa over three years was N=26 (6.4%). Conclusion: The present study revealed a high period prevalence of MRSA colonisation (6.4%) in patients undergoing TJAs. Therefore, all elective TJAs should undergo MRSA screening and decolonisation using 2% intranasal mupirocin and daily chlorhexidine body wash for five days as a successful treatment modality for all patients with MRSA-positive nasal colonisation. This approach helps prevent postoperative SSIs caused by MRSA.

Pregnancy-associated asymptomatic bacteriuria and antibiotic resistance in the Maternity and Children's Hospital, Arar, Saudi Arabia.

The Ministry of Health in Saudi Arabia provides comprehensive antenatal care for all pregnant women with all required investigations. However, it does not include urine culture for diagnosis of asymptomatic bacteriuria (ASB). This is the first study to evaluate the prevalence of ASB among pregnant females, identify the causative organisms and determine their antibiotic susceptibility patterns in the Maternity and Children's Hospital, Arar, Saudi Arabia. This cross-sectional study included 400 pregnant women attending an antenatal clinic. Two midstream urine samples were aseptically collected and screened using standard microbiological techniques including microscopic examination, dipstick testing, and urine culture. In order to interpret the urine culture results, ≥ 105 CFUs/mL was considered significant bacteriuria. Identification of the isolates and their antibiotic sensitivity testing was performed using the Vitek 2 system (BioMérieux, Marcy l'Etoile, France) with the available test kits. The prevalence of ASB was 8.25% (35/400). Significant positive correlations (p ˂ 0.05) were detected between positive urine culture results and random blood sugar, leucocytes, nitrites, pus cells, urine red blood cells, epithelial cells, and mucus. Escherichia coli was the most common causative organism (45.7%), followed by Staphylococcus aureus (22.9%). Klebsiella pneumoniae represented 11.4% of the isolates. Most of the isolated Gram-positive organisms were sensitive to many of the tested antibiotics; most of the detected Gram-negative isolates were resistant. ASB caused by antibiotic resistant organisms is alarming. Screening for ASB during pregnancy using urine culture and sensitivity testing is of vital importance to improve the maternal and neonatal outcome.

Variability of bile bacterial profiles and drug resistance in patients with choledocholithiasis combined with biliary tract infection: a retrospective study.

Biliary tract infection is a common complication of choledocholithiasis. This study aimed to analyse the distribution of pathogenic bacteria in bile cultures from patients with choledocholithiasis combined with biliary tract infection to guide clinical application of antimicrobials and reduce the emergence of drug resistance. A total of 880 patients were enrolled in this retrospective study from 30 March 2017 to 31 August 2022 at the Affiliated Hospital of Qingdao University in China. Bile specimens were extracted for microbiological culture under aseptic conditions using endoscopic retrograde cholangiopancreatography. Bacterial culture, strain identification, and antimicrobial susceptibility testing were conducted according to the standard protocol. Baseline data were retrieved from patient files. Overall, 90.34% (795/880) of bile samples showed positive microbiological results and 37.50% (330/880) demonstrated polymicrobial infections. Among the 795 bile specimens with positive culture results, 1,216 pathogenic bacteria were detected, with gram-negative bacilli accounting for 56.33%, gram-positive cocci for 41.86%, and fungi for 1.81%. The predominant gram-negative bacilli in the bile cultures were Escherichia coli (30.43%) and Klebsiella pneumoniae (13.98%), whereas the main gram-positive cocci were Enterococcus faecium (14.04%) and E. casseliflavus (4.28%). The annual trend analysis revealed a gradual decrease in the proportion of gram-negative bacilli and a gradual increase in the proportion of gram-positive cocci, with a concomitant decrease in the dominance of E. coli. Both E. faecium and E. coli showed high resistance to conventional antibiotics but high sensitivity to piperacillin/tazobactam, carbapenems, amikacin, and vancomycin. A significant change has occurred in the bile bacterial spectrum in patients with choledocholithiasis and biliary tract infection. The incidence of gram-positive cocci infections has increased annually, while that of gram-negative bacilli and E. coli infections has decreased. Antibiotic administration should be tailored based on the local bacterial profile.

Rectal culture could predict carbapenem-resistant organism bloodstream infection and reduce the mortality in haematological patients: A retrospective cohort study

The objective is to explore the correlation between rectal swab culture and the overall 30-d survival of hematologic patients diagnosed with carbapenem-resistant organism (CRO) bloodstream infection. A total of 434 haematological patients who were complicated with Gram-negative bacilli (GNB) bloodstream infections (BSIs) caused by Gram-negative bacteria between January 2020 and December 2021 were included in our retrospective study. Based on their drug susceptibility results, we classified patients into CRO BSIs and non-CRO BSIs cases. Through group comparison, to uncover the correlation between the positive screening of rectal swabs and reducing the mortality of CRO BSI in patients with haematological diseases. Among the 434 cases of Gram-negative bacteria bloodstream infection, 96 were identified as carbapenem-resistant bloodstream infection, which consisted of 57 cases of carbapenem-resistant Klebsiella pneumoniae (CR-KP), 19 cases of carbapenem-resistant Pseudomonas aeruginosa (CR-PA), 11 cases of carbapenem-resistant Escherichia coli (CR-CO), 5 cases of carbapenem-resistant Acinetobacter baumannii (CR-AB), and 4 cases of other Enterobacteriaceae. Before the onset of CRO bloodstream infection, rectal swab cultures were conducted on 36 patients, and the positive result rate was 75.0% (27/36), with 20 cases of CR-KP, 6 cases of CR-CO, and one case of carbapenem-resistant Enterobacter cloacae. It was observed that the rectal and blood cultures had matching outcomes in 75.0% of cases. The mortality rate within 30 d for CRO BSIs was 53.1% (51/96), while for carbapenem-resistant Enterobacteriaceae (CRE) BSIs it was 62.5% (45/72). Univariate analysis showed that 30-d mortality was significantly reduced when there were positive rectal culture results preceding bloodstream infection (P < 0.001), as well as preemptive anti-infection treatment (P < 0.001). Multivariate analysis demonstrated that preemptive adjustment to an effective antibiotic regimen, guided by positive rectal culture results, had a significant effect on decreasing 30-d mortality following CRO BSIs (P= 0.002). Furthermore, for the management of CRE BSIs, antibiotic treatments utilising ceftazidime/avibactam (CAV/AVI) may be more beneficial compared to those that use tigecycline (TGC) or polymyxin (PMB). CRO BSI, especially CRE BSI, can be life-threatening for those with haematological diseases. Utilising rectal culture can effectively identify CRO strains with high sensitivity and specificity. Adjusting antibiotic treatment based on the preemptive positive rectal culture results may significantly decrease 30-d mortality rates for haematological patients with CRO BSIs.

Metagenomic identification of pathogens and antimicrobial-resistant genes in bacterial positive blood cultures by nanopore sequencing.

Nanopore sequencing workflows have attracted increasing attention owing to their fast, real-time, and convenient portability. Positive blood culture samples were collected from patients with bacterial bloodstream infection and tested by nanopore sequencing. This study compared the sequencing results for pathogen taxonomic profiling and antimicrobial resistance genes to those of species identification and phenotypic drug susceptibility using traditional microbiology testing. A total of 37 bacterial positive blood culture results of strain genotyping by nanopore sequencing were consistent with those of mass spectrometry. Among them, one mixed infection of bacteria and fungi was identified using nanopore sequencing and confirmatory quantitative polymerase chain reaction. The amount of sequencing data was 21.89 ± 8.46 MB for species identification, and 1.0 MB microbial strain data enabled accurate determination. Data volumes greater than or equal to 94.6 MB nearly covered all the antimicrobial resistance genes of the bacteria in our study. In addition, the results of the antimicrobial resistance genes were compared with those of phenotypic drug susceptibility testing for Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. Therefore, the nanopore sequencing platform for rapid identification of causing pathogens and relevant antimicrobial resistance genes complementary to conventional blood culture outcomes may optimize antimicrobial stewardship management for patients with bacterial bloodstream infection.

Increase in antibiotic resistance in diabetic foot infections among peruvian patients: a single-center cross-sectional study.

Diabetic foot is one of the most significant complications in individuals with diabetes and is closely associated with lower limb amputation. The antibiotic susceptibility patterns of these bacterial isolates play a critical role in guiding effective treatment strategies We aimed to determine the most common bacterial agents causing diabetic foot infections in a tertiary-care hospital in Peru. Clinical and microbiological data were collected from 181 patients diagnosed with diabetic foot infections and positive microbiological culture results. All the samples were analyzed with the Vitek 2 compact system and the cut-off points were defined with the CLSI M100 guide. The data were segregated based on mono-microbial or poly-microbial cultures, bacterial types, and antibiotic susceptibility profiles. A total of 32 bacterial species were identified, predominantly Gram-negative (63%). The most frequent bacterial agents isolated were Staphylococcus aureus (19.9%), Escherichia coli (12.2%), Pseudomonas aeruginosa (8.3%), and Proteus vulgaris (6.6%). These bacteria commonly exhibited resistance to Ampicillin, Ciprofloxacin, Levofloxacin, Trimethoprim-sulfamethoxazole, and Cefuroxime. E. coli showed the highest antibiotic resistance (19 antibiotics), while Gentamicin, Tobramycin, and Levofloxacin demonstrated the highest sensitivity against the most prevalent bacteria. Gram-negative bacteria also exhibited notable antibiotic-susceptibility to Meropenem, Piperacillin/tazobactam, and Amikacin. Regarding the presence of Extended-Spectrum Beta-Lactamase, 54 isolates tested positive, with 35 (64.8%) and 14 (42.4%) of these being S. aureus and E. coli. Bacterial agents causing diabetic foot infections pose a constant concern, particularly due to the increasing antibiotic resistance observed. This difficulty in treating the condition contributes to a higher risk of amputation and mortality. Further research on bacterial susceptibility is necessary to determine appropriate dosages for pharmacological treatment and to prevent the overuse of antibiotics.

Relationship between blood culture time to positivity, mortality rate, and severity of bacteremia

ObjectivesWe investigated the association between patient severity or mortality and time to positivity in bacteremia caused by various pathogens. Patients and methodsThis single-center retrospective study included patients with positive blood culture results. ResultsLonger time to positivity was associated with 30-day mortality for Staphylococcus aureus (221 cases, time to positivity: 17.4 h in the 30-day mortality group vs. 14.1 h in the survival group). Age, chronic kidney disease, cerebrovascular disease, hypertensive drug use, consciousness disorder, and minimal systolic blood pressure were significant predictors of 30-day mortality. For S. aureus, mortality within 30 days was significantly higher when time to positivity was > 24 h (p = 0.04). The time to positivity of Streptococcus pneumoniae, α, β-hemolytic Streptococcus, Enterococcus sp., Enterobacteriaceae, glucose-nonfermenting Gram-negative rods, Candida sp., and anaerobe was not significantly associated with 30-day mortality. ConclusionsAmong various pathogens, time to positivity > 24 h was associated with 30-day mortality for S. aureus.

Prognosis of spontaneous bacterial peritonitis in patients with hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is the fourth leading cause of death from cancer worldwide. Spontaneous bacterial peritonitis (SBP) is associated with poor prognosis. This study aimed to evaluate risk factors, differences in clinical characteristics and prognosis of SBP in patients with HCC in comparison with non-HCC patients. MethodsThis study was conducted on patients with cirrhosis who were admitted to hospital with SBP. The patients were divided into two groups: SBP group with HCC (n = 150) and SBP group without HCC (n = 250). ResultsMen and women accounted for 72% and 28% (n = 108 and 42, respectively) of the population in SBP group with HCC with mean age 55.8 ± 13.1 years. They accounted for 68.4% and 31.6% (n = 171 and 79, respectively) in the SBP group without HCC with mean age 56.8 ± 10.5 years. In-hospital mortality was 25.3% in the SBP group with HCC and 18.8 % in SBP group without HCC. Gastrointestinal bleeding was the most common cause of death in both groups. No significant difference was observed in patient outcomes between the two studied groups. The deceased patients had significantly higher levels of leukocytes and neutrophils in ascitic fluid as well as a higher frequency of positive culture results than in patients who survived (p < 0.001). However, there was no significant difference in protein level in ascitic fluid or causative organism between patients who survived and those who died (p = 0.63 and 0.19, respectively). ConclusionsPrognosis of SBP in patients with HCC seemed similar to that in patients without HCC.

State-of-the-Art Review: Persistent Enterococcal Bacteremia.

Persistent enterococcal bacteremia is a commonly encountered and morbid syndrome without a strong evidence base for optimal management practices. Here we highlight reports on the epidemiology of enterococcal bacteremia to better describe and define persistent enterococcal bacteremia, discuss factors specific to Enterococcus species that may contribute to persistent infections, and describe a measured approach to diagnostic and therapeutic strategies for patients with these frequently complicated infections. The diagnosis of persistent enterococcal bacteremia is typically clinically evident in the setting of repeatedly positive blood culture results; instead, the challenge is to determine in an accurate, cost-effective, and minimally invasive manner whether any underlying nidus of infection (eg, endocarditis or undrained abscess) is present and contributing to the persistent bacteremia. Clinical outcomes for patients with persistent enterococcal bacteremia remain suboptimal. Beyond addressing host immune status if relevant and pursuing source control for all patients, management decisions primarily involve the selection of the proper antimicrobial agent(s). Options for antimicrobial therapy are often limited in the setting of intrinsic and acquired antimicrobial resistance among enterococcal clinical isolates. The synergistic benefit of combination antimicrobial therapy has been demonstrated for enterococcal endocarditis, but it is not clear at present whether a similar approach will provide any clinical benefit to some or all patients with persistent enterococcal bacteremia.