Culture Specimens Research Articles

P-944. Usefulness of PCR and Culture of Specimens Obtained at Surgery in Patients with Infective Endocarditis

Abstract Background By 2016 it was standard protocol at Cleveland Clinic that patients undergoing surgery for confirmed or suspected infective endocarditis (IE) had cardiac specimens tested by both culture and 16s rRNA PCR and amplicon sequencing (PCR) to verify or accurately identify the causative pathogen. The purpose of this study was to compare the sensitivities and false positive rates, of PCR and culture of cardiac specimens obtained at surgery, among patients with infective endocarditis. Methods This was a retrospective cohort study. Episodes of pathologically-proven bacterial endocarditis with a single causative pathogen, among patients who underwent surgery for IE from January 1, 2016, to January 1, 2021 were identified from the Cleveland Clinic Infective Endocarditis Registry. The causative pathogen in the registry is determined by criteria that consider blood culture, histopathological findings, and culture and PCR of surgical specimens. Sensitivities of culture and PCR were compared, as were the false positive rates for PCR and culture among tests that were positive. Results Microbiological testing was done on 1326 fresh tissue specimens from 731 episodes of IE among 706 unique patients during the 5-year study period. PCR was significantly more sensitive than culture in detecting the pathogen (79.6% vs. 31.6%, p-value < 0.001). After adjusting for the number of specimens tested per IE episode, the odds of detecting the pathogen were significantly higher for PCR than for culture (OR 10.60, 95% C.I. 8.23 – 13.74, p-value < 0.001). Specimens that tested positive were false positives 1.6% and 10.1% of the time, for PCR and culture, respectively. Among specimens that tested positive, the odds of a positive test result being a false positive were significantly lower for PCR than for culture (13/795 vs 35/313, OR 0.15, 95% C.I. 0.07 – 0.27, p-value < 0.001). Conclusion The causative pathogen for IE is much more likely to be identified by PCR of surgical specimens than by culture. Conversely, a positive culture from a surgical specimen is much more likely to be a contaminant than a positive PCR. Disclosures Hannah Wang, MD, Hologic: Advisor/Consultant

P-656. Investigating the Current Status and Exploring Issues for the Construction of Ventilator-Associated Pneumonia Surveillance

Abstract Background Ventilator-associated pneumonia (VAP) is a major infectious complication in invasive mechanical ventilation (IMV)-controlled patients. Because VAP adversely affects multiple outcomes, including risk of death, length of intensive care unit (ICU) stays, and length of hospital stay, appropriate preventive measures need to be constructed. To establish preventive measures for VAP in our hospital, we surveyed the occurrence of VAP and summarized the issues identified in the process. Methods Patients who received 48 hours or more of IMV at our hospital in 2023 were included in this study. We retrospectively studied the number of ventilator-associated conditions (VAC), infection-related ventilator-associated complications (IVAC), and probable/possible VAP (PVAP) events using the ventilator-associated events (VAE) algorithm from the Centers for Disease Control and Prevention National Healthcare Safety Network. We used the records of ventilator settings used by medical engineers (ME) for daily ventilator check-ups to screen for VAC events. Clinical findings, including the results of bacteriological tests of lower respiratory tract specimens, were investigated using electronic medical records. Results Of the 143 patients (157 IMV events) who underwent IMV during the study period, 102 (113 IMV events) were eligible patients. There were 23, 8, and 3 events of VAC, IVAC, and PVAP, respectively. The incidence of VAC, IVAC, and PVAP per 100 IMV events was 20.4, 7.1, and 2.7, respectively. The main causes of VAC events other than IVAC and PVAP were pulmonary edema in 4 events and septic shock in 3 events. During this study, screening for VAC events was readily available in the ME inspection records. In contrast, because of the overlap in ordering methods for culture of lower respiratory tract specimens under ventilatory management and self-discharged sputum, it became necessary to comprehensively review the electronic medical record of the patient in question for bacteriological testing. Conclusion In our VAP surveillance, the proportion of IVAC and PVAP events in VAC events was small. To ensure smooth VAP surveillance, the method of ordering bacteriological tests needs to be revised. Disclosures All Authors: No reported disclosures

315. Modeling Strain-Dependent Variability in Carbapenem-Resistant Klebsiella pneumoniae Colonization in the Malnourished Host

Abstract Background Particular strains of Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) have achieved global dominance extending to developing countries where malnutrition is a potential risk factor for infection. Bacteria and host properties that determine colonization dynamics in this context are not understood. We hypothesized that strain variability in host cell adhesion and nutrient-utilization in vitro predicts in vivo intestinal colonization by CR-Kp in malnourished hosts.Figure 1:Strain-dependent cell adhesion by carbapenem-resistant Klebsiella pneumoniae(A) Adhesion to Colo-201 cells and/or (B) Caco-2 cells as percentage of bacteria recovered after co-culturing then washing off non-adherent cells. Bacterial quantification performed by culturing on MacConkey agar + Meropenem. Strains of interest indicated with arrows and colored-bars. All experiments showing results of 3 replicates. Methods Patient-derived isolates of CR-Kp were subject to in vitro assays testing adhesion to human colon cell lines. Select isolates were further tested for in vitro growth in minimal media with limiting protein availability. These isolates were additionally inoculated via orogastric lavage into C57BL/6 mice (n=6 per group) on a nutrient replete control diet (CD) or isocaloric protein-deficient diet (PD) and intestinal colonization was quantified with selective culture of feces and intestinal specimens on MacConkey agar containing meropenem.Figure 2:Nutrient limited growth of carbapenem-resistant Klebsiella pneumoniaeGrowth in vitro determined by serial absorption measurement of bacteria culture under different nutrient conditions. M9 minimal medium (M9mm; M9 solution +0.4% glucose) was used with or without casein peptone (0.16% or 0.016%) as a protein/amino acid source. Results Across >100 screened human isolates of CR-Kp, adhesion to human colon cell lines ranged from < 1% to 30% (Figure 1). Three high-adhesion isolates (Kp175, Kp4493 and Kp4605) and one low-adhesion isolate (Kp4404) were selected for further investigation (Table 1). All three high-adhesion isolates grew to varying degrees in protein-limited conditions, while Kp4404 required a protein source for growth (Figure 2). Mice inoculated with CR-Kp were stably colonized only if they were fed a PD rather than CD diet. Kp175 and Kp4605 demonstrated the highest fecal shedding and intestinal burden (102-104 CFU per mg), which was significantly greater on a PD versus CD diet (p< 0.05 by Mann-Whitney test). In contrast, Kp4493 and Kp4404 inconsistently colonized mice regardless of diet (Figure 3).Figure 3:Diet-dependent intestinal colonization by carbapenem-resistant Klebsiella pneumoniae(A) 3-4 wk old C57BL/6 male mice initiated on nutrient-replete control diet (CD) or isocaloric protein-deficient diet (PD) and inoculated via orogastric lavage with 10^6 CFU of carbapenem-resistant Klebsiella pneumoniae (CR-Kp). (B) Weight measured over time along with bacterial burden in (C) fecal pellets and (D) intestinal tissue by culturing on MacConkey agar + Meropenem. 6 animals used per condition. * = p<0.05 by Mann Whitney Test. Conclusion Our findings suggest a wide variability in intestinal cell adhesion and nutrient utilization by clinical isolates of CR-Kp. These in vitro properties incompletely predict in vivo colonization in a mouse model. Notably, host dietary deficiency promotes intestinal colonization by certain nutritionally resilient CR-Kp isolates, with potential implications for the global spread of high-risk strains in malnourished populations.Table 1:Genotypic, clinical and phenotypic characteristics of carbapenem-resistant Klebsiella pneumoniae Adhesion percentage express as mean (standard deviation). Disclosures David van Duin, MD, PhD, Merck: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Advisor/Consultant|Qpex: Advisor/Consultant|Roche: Advisor/Consultant|Shionogi: Advisor/Consultant|Shionogi: Grant/Research Support

P-1502. Clindamycin and Group A Streptococcus: Is It Time To Say Goodbye?

Abstract Background Group A streptococci (GAS) can cause invasive disease leading to Toxic Shock Syndrome (TSS), a condition linked with high mortality. Initial antibiotic therapy for GAS-TSS includes beta-lactams and clindamycin. When clindamycin resistance is noted, linezolid may be used instead until clinical stability is achieved. We reviewed GAS susceptibility at IUH Ball Memorial Hospital to assess appropriateness of initial clindamycin use as adjunctive therapy for GAS-TSS. Methods GAS positive cultures recovered from 1/1/23 – 12/31/23 at IU Health Ball Memorial Hospital, Muncie, IN were reviewed. Results Out of 162 cultures positive for GAS, 29 (17.9%) had susceptibility results. All 29 GAS specimens were sensitive to penicillin and linezolid, but only 16/29 (55.2%) specimens were sensitive to clindamycin. Table 1. and Chart 1. show susceptibility results for penicillin, clindamycin, erythromycin, and linezolid. Table 2. shows number of specimens with inducible clindamycin resistance. Chart 2. shows various sources of culture specimens. Conclusion GAS susceptibility testing was performed with invasive infections or when requested. Significant resistance was noted to clindamycin. Although our data is limited by a small sample size, it is in line with trends noted by US CDC’s Active Bacterial Core surveillance reports. This raises concern over initial use of clindamycin for TSS before susceptibilities are available. There are both advantages and disadvantages associated with use of clindamycin or linezolid. There is more data to support clindamycin use, however it is linked with increased risk of C. difficile infections. There is limited data for the use of linezolid for this indication, but it does maintain better susceptibility and negates the use of vancomycin at time of empiric therapy. Even though more data may be needed to definitively recommend linezolid over clindamycin or vice versa, clinical decisions will need to be made prior to susceptibility results. We recommend clinicians utilize their local antibiograms to guide decision making, while also accounting for patient factors. This also provides an opportunity for the development of clinical practice guidelines to better assist clinicians in the community. Disclosures All Authors: No reported disclosures

P-2088. Correlation of pediatric blood culture transport time and time-to-positivity since microbiology service centralization

Abstract Background Guidance from Clinical & Laboratory Standards Institute (CLSI) and Infectious Diseases Society of America (IDSA) both recommend that transport of blood culture specimens from collection to laboratory accession should take less than 2 hours to preserve the specimen quality, such as positivity rate and time-to-positivity (TTP). This recommendation could be impractical in Canada as many diagnostic microbiology laboratories are moving towards centralization, in which microbiology services are relocated from individual laboratories to regional sites, where resources and personnel are consolidated. This is especially crucial for the pediatric population as different published guidelines are available on the required pediatric blood culture volume, which could affect their positivity rate and TTP. Methods The current study investigated the blood culture transport time and TTP for Children’s Hospital of Eastern Ontario (CHEO), a tertiary pediatric hospital, situated about 700 meters away from Eastern Ontario Regional Laboratory Association (EORLA) microbiology laboratory, which has consolidated the microbiology services for 18 hospitals in Eastern Ontario since 2010’s. All first positive blood cultures from patients at CHEO from 1 November 2019 to 31 October 2020 were included. TTP was defined as the time from collection to a positive signal from the automated incubators. Two-tailed Spearman’s correlation was used to determine the association between transport time and TTP. Results A mean transport time of 2.95 hours and a mean TTP of 31.8 hours were calculated from the 268 episodes of first positive blood culture from patients in a year (mean patient age 6.27 years). Only 82 specimens were transported to the laboratory in less than 2 hours. A weak but statistically significant correlation (rs = 0.17, p = 0.0047.) was observed between transport time and TTP. Conclusion Even for a hospital within walking distance of a regional microbiology laboratory, the blood culture transport time was unable to meet the guidance recommendation, associated with delay in TTP. Centralization of microbiology services could affect the quality of critical clinical specimens. Remedial actions, such as molecular testing, could be considered to salvage specimens if they are crucial for diagnoses. Disclosures All Authors: No reported disclosures

P-2166. Sensitivity and Specificity of Nanopore Sequencing for Detection of Methicillin-Resistant Staphylococcus aureus and Methicillin-Resistant Staphylococcus epidermidis in Positive Blood Culture Samples

Abstract Background Nanopore sequencing enables rapid DNA/RNA analysis without amplification. Implementing this for point-of-care diagnostics reduces time delays in traditional AST methods, potentially enhancing patient outcomes. We aim to evaluate the performance of Oxford Nanopore Technologies sequencing from positive blood culture for bacterial identification and antimicrobial susceptibility prediction in S. aureus and S. epidermidis by detecting the mecA gene. Methods We conducted a cross-sectional descriptive study on individuals with positive blood cultures identifying S. aureus and S. epidermidis over a 12-month period from April 2023 to March 2024. Bacterial DNA was extracted from the blood culture specimens, and then sequenced using the PromethION Flow Cell to identify the organisms and mecA genes, comparing the results to routine blood cultures and standard AST. Results 108 blood culture samples were initially collected. After applying the exclusion criteria, 80 samples qualified for DNA extraction and sequencing. 45 samples were identified as S. aureus (6 MRSA and 39 MSSA) and 35 as S. epidermidis (27 MRSE and 8 MSSE). Notably, 67.5% of samples contained less than 0.5 ng/μl of DNA. Sensitivity and specificity of mecA gene detection were 35.5% (95% CI: 18.6%–52.3%) and 83.7% (95% CI: 73.3%–94.0%), respectively, with an accuracy of 65.0% (95% CI: 54.5%–75.5%). Upon excluding samples with DNA less than 0.5 ng/μl accuracy improved to 73.1% (95% CI: 56.0%–90.1%). The specimen that showed a false-positive result will proceed to phenotypic confirmation using methicillin-infused mannitol-salt agar. After phenotypic confirmation, the accuracy improved to of 88.5% (95% CI: 76.2%–100.0%). In this study, we also found 5 samples in which the mecA gene was shown to be genotypically oxacillin-sensitive after phenotypic confirmation. The median time for detecting the mecA gene was 198 minutes (IQR: 37.5–458.7) after the onset of sequencing. Conclusion Our study on nanopore sequencing for MRSA and MRSE detection from blood cultures found promising but limited sensitivity and specificity in detecting mecA gene. Challenges in DNA extraction from Gram-positive bacteria affected overall accuracy. Further improvements are needed for enhanced diagnostic reliability. Disclosures All Authors: No reported disclosures

P-875. Bacteroides spp. drug resistance in patients with anaerobic bacteremia: a multicentric retrospective observational study

Abstract Background Bacteroides spp. are important causative anaerobes in intra-abdominal infections; however, recent reports have shown a trend toward drug resistance in non-Bacteroides fragilis. The present study aimed to evaluate bacteremia due to Bacteroides spp. by performing a multicentric retrospective observational study. Methods Obligate anaerobes isolated from blood culture specimens were collected from patients at Nagasaki University Hospital and five core hospitals in Toyama Prefecture from January 2012 to March 2022. Of a total of 528 patients, 102 specimens with B. fragilis and 72 with non-B. fragilis were clinically characterized using Fisher’s exact test and multiple logistic regression analysis. Drug-resistant rates over time were analyzed by the Spearman rank correlation test. Results In the non-B. fragilis group, compared to the B. fragilis group, the clindamycin resistance rate (non-B. fragilis group [59.7%] vs. B. fragilis group [38.2%] odds ratio [OR]=2.40 [95% confidence interval [CI]; 1.23–4.43] p=0.0058) and carbapenem resistance rate (non-B. fragilis group [27.8%] vs. B. fragilis group [10.8%] OR=3.18 [95%CI; 1.41–6.78] p=0.0049) was significantly increased. Furthermore, in the non-B. fragilis group, excluding patients who died owing to an underlying disease, a significantly increased 30-d mortality rate (non-B. fragilis group [16.7%] vs. B. fragilis group [5.9%] OR=3.20 [95%CI; 1.15–8.91] p=0.0251) was observed. Moreover, as of risk factors for 30-d mortality in non-B. fragilis bacteremia, SOFA score (adjusted OR=1.30 [95%CI; 1.11–1.57] p=0.0027) and carbapenem resistance (adjusted OR=7.05 [95%CI; 1.54–41.9] p=0.0171) were elucidated. Of note, in the non-B. fragilis group, rather than the B. fragilis group, the carbapenem resistance rate (non-B. fragilis group [r = 0.77, p=0.0141] vs. B. fragilis group [r = 0.17, p=0.6433]) and tazobactam/piperacillin resistance rate (non-B. fragilis group [r = 0.78, p=0.0120] vs. B. fragilis group [r = -0.05, p=0.8988]) have increased over time. Conclusion Non-B. fragilis isolated from blood cultures, compared to B. fragilis, exhibited an increasing trend in carbapenem and tazobactam/piperacillin resistance and contributed to 30-d mortality. Disclosures Shigeru Kohno, n/a, SHIONOGI & CO., LTD.: Board Member|SHIONOGI & CO., LTD.: Grant/Research Support Hiroshi Mukae, M.D., Ph.D., AstraZeneca: Lecture fees|Gilead Sciences: Lecture fees|GSK: Lecture fees|MSD: Advisor/Consultant|MSD: Lecture fees|Pfizer: Lecture fees|Shionogi & Co., Ltd.: Advisor/Consultant|Shionogi & Co., Ltd.: Grant/Research Support|Shionogi & Co., Ltd.: Lecture fees

Performance of multiplex PCR-based targeted next-generation sequencing in bronchoalveolar lavage fluid for the diagnosis of invasive pulmonary aspergillosis in non-neutropenic patients.

Multiplex polymerase chain reaction (PCR)-based targeted next-generation sequencing (tNGS) is a promising tool for distinguishing lower respiratory tract infections (LRTIs) in clinical practice, and its detectable pathogen spectrum can cover more than 95% of clinical cases. but there is limited information on systematic evaluation of the clinical use of multiplex PCR-based tNGS (mp-tNGS) in IPA cases. We aim to assess mp-tNGS in bronchoalveolar lavage fluid (BALF) for Aspergillus detection in suspected IPA patients, and to provide a reliable basis for initiating antifungal therapy without microbiological or histopathological evidence. We prospectively enrolled a cohort of consecutive patients suspected of IPA, all of them had undergone serum/BALF galactomannan antigen (GM), BALF mp-tNGS, and traditional tests (direct smear and culture of respiratory specimens), EORTC/MSGERC and FUDICU criteria were used for IPA diagnosis. Thirty-two patients were diagnosed with IPA and 42 with non-IPA. Compared with the final diagnosis, the sensitivity of BALF mp-tNGS was 87.5%, while the sensitivity of traditional tests, serum GM and BALF GM assay was 43.8%, 21.9%, and 62.5%, respectively; the specificity of BALF mp-tNGS was 90.5%, which was similar to traditional tests. The average turnaround time (TAT) for Aspergillus detection by BALF mp-tNGS was 22.10±2.49h, which was significantly faster than that by traditional tests. BALF mp-tNGS showed good performance in identification of Aspergillus in non-neutropenic IPA patients. Importantly, positive mp-tNGS in BALF can provide a basis for early antifungal therapy before microbiological evidence is available.

Early onset neonatal bloodstream infections in South African hospitals

BackgroundNeonatal sepsis is a leading cause of death in low- and middle- income countries (LMIC). Increasing antibiotic resistance in early onset (< 72 h of life) bloodstream infection (EO-BSI) pathogens in LMIC has reduced the effectiveness of the recommended empiric antibiotic regimen (ampicillin plus gentamicin).MethodsWe retrospectively analysed blood culture-confirmed EO-BSI episodes at nine neonatal units from three central and six peripheral hospitals in the Western Cape Province, South Africa between 1 January 2017 and 31 December 2018. Clinical and electronic laboratory records were reviewed to determine pathogen profile, empiric antibiotic coverage rates and factors associated with EO-BSI attributable mortality, stratified by hospital type.ResultsOf the 8252 blood culture specimens submitted for the investigation of suspected EO-BSI, 136 EO-BSI episodes yielding 141 pathogens were identified with an EO-BSI rate of 1.3 and 0.5 episodes/1000 live births at central and peripheral hospitals respectively. Preterm (93/136; 68.3%) and low birth weight (84/136; 61.8%) neonates were most affected. The predominant pathogens were Streptococcus agalactiae (46/136; 34%), Klebsiella pneumoniae (17/136; 13%), Listeria monocytogenes (11/136; 8%), Acinetobacter baumannii (11/136; 8%) and Escherichia coli (11/136; 8%). The empiric antibiotic (ampicillin plus gentamicin) coverage rate was 64% (95% CI 51–74) at central hospitals and 84% (95% CI 74–94) at peripheral hospitals. Neonates with Gram-negative EO-BSI and discordant empiric antibiotic therapy had almost four-fold and three-fold higher odds of death respectively.ConclusionPreterm and low birth weight neonates are most vulnerable to EO-BSI and have higher odds of death with Gram-negative pathogens and discordant empiric antibiotic therapy.

Impact on the Proper Use of Antimicrobials for Patients with Gram-negative Bacteremia due to a Change in Testing Location of Positive Blood Culture Specimens

Impact on the Proper Use of Antimicrobials for Patients with Gram-negative Bacteremia due to a Change in Testing Location of Positive Blood Culture Specimens

Vaginal antiseptic preparation at the time of hysterectomy: a systematic review and meta-analysis.

This study aimed to compare the rates of surgical site infection after hysterectomy using vaginal antisepsis with chlorhexidine gluconate vs povidone-iodine. PubMed, Embase, and ClinicalTrials.gov databases were queried from January 1, 1985 through December 7,2023. Randomized controlled trials and nonrandomized comparisons of interventions of chlorhexidine gluconate and povidone-iodine vaginal antiseptic preparation before hysterectomy were included. The primary outcome was surgical site infection as defined by the Centers for Disease Control and Prevention. Secondary outcomes included postoperative urinary tract infections and vaginal culture specimens. Large single-group studies of vaginal chlorhexidine gluconate reporting adverse events and case reports of desquamation were also included. The methodologic quality of each study was assessed using the original Cochrane RoB (Risk of Bias) and ROBINS-I (Risk of Bias in Non-Randomized Studies - of Interventions) tools. Restricted maximum likelihood meta-analyses of odds ratios were conducted. A total of 5289 abstracts were screened; 10 met the inclusion criteria, with a total of 9618 participants. The studies included 4 randomized controlled trials (n=306), 3 prospective nonrandomized comparisons of interventions (n=1089), and 3 retrospective nonrandomized comparisons of interventions (n=8223). Povidone-iodine was compared with 4% chlorhexidine gluconate in 4 studies (n=2491), 2% chlorhexidine gluconate in 2 studies (n=236), 0.1% chlorhexidine gluconate in 1 study (n=50), and both 2% and 4% chlorhexidine gluconate in 1 study (n=49). Meta-analysis revealed no statistically significant difference in surgical site infections, although they were somewhat more common with chlorhexidine gluconate (summary odds ratio, 1.22; 95% confidence interval, 0.91-1.63). The relative effect of antiseptic preparations on urinary tract infections was unclear, with an imprecise summary odds ratio (1.18; 95% confidence interval, 0.65-2.12). Positive vaginal cultures were less common with chlorhexidine gluconate preparation (summary odds ratio, 0.10; 95% confidence interval, 0.04-0.27). Two studies reported no adverse events with chlorhexidine gluconate, and 2 found no difference in vaginal irritation when compared with povidone-iodine. Two case reports described vaginal desquamation or hypersensitivity with chlorhexidine gluconate. There is no evidence of a difference in postoperative infection with chlorhexidine gluconate use compared with povidone-iodine, but chlorhexidine gluconate vaginal preparation results in lower rates of positive intraoperative vaginal cultures. Despite inadequate reporting, risk of adverse events appears low.

Continuous Threat of Growing Antimicrobial Resistance Among Salmonella Typhi Isolates: A Multicenter Study from Pakistan

Objective: To determine current susceptibility patterns of Salmonella enterica serovar Typhi (S. Typhi) in four cities of Pakistan and to deduce the frequency of multidrug resistant, extensively drug-resistant S. Typhi. Study Design: Cross-sectional study. Place and Duration of Study: Departments of Microbiology, Pakistan Navy Ship Shifa Hospital, Karachi, Pak Emirates Military Hospital, Rawalpindi, Combined Military Hospital, Sialkot, Combined Military Hospital, Abbottabad, Pakistan, from Apr 2019 to Sep 2020. Methodology: Blood culture specimens of patients with suspected Enteric fever from four different institutes were received in respective laboratories. Culture and identification of isolates were done and specimens yielding growth of S. Typhi, were included in the study. Antibiotic susceptibility was tested according to Clinical and Laboratory Standards Institute guidelines 2019 and 2020. Results: A total of 970 blood culture specimens yielded growth of S. Typhi. Maximum isolates were found from Pak Emirates Military Hospital, Rawalpindi, 395(40.7%) followed by Pakistan Navy Ship Shifa, Karachi 366(37.7%). The total number of multidrug resistant isolates were 679 (70%) and extensively drug resistant isolates were 457(47.1%) with maximum number of multidrug resistant and extensively drug resistant S. Typhi from Pakistan Navy Ship Shifa. Ciprofloxacin susceptible isolates were 50(5.2%) and maximum sensitive isolates were from Combined Military Hospital, Abbottabad. Resistance to azithromycin was found in four isolates (0.4%). There were no isolates resistant to meropenem. Conclusion: Emergence of antibiotic resistance among S. Typhi strains is a threat which emphasizes the importance of surveillance of antimicrobial susceptibility patterns and amendment of current antibiotic prescribing practices.

Predictors of Nosocomial Infections among Geriatric Patients in the Internal Medicine Department of the University Teaching Hospital of Butare (CHUB), South, Huye, Rwanda

Purpose: Nosocomial infections pose a significant burden worldwide, particularly in resource-limited settings. This study aimed to determine predictors of nosocomial infections among geriatric patients at the University Teaching Hospital of Butare (CHUB) in Rwanda. Methodology: A quantitative cross-sectional cohort study over seven months included participants admitted to CHUB's Internal Medicine department from July 2023 to January 2024 with the aim to determine the Nosocomial infections predictors among elderly aged 61 years and above. The target sample size was 313, but a census approach with 400+ participants was used. Data collection involved physician examinations, laboratory testing, interviews, facility observations, specimen culture, antimicrobial susceptibility testing, and logistic regression analyses. Findings: The study included 206 participants who were screened infection-free at admission, predominantly from Southern Province (85%) and female (56%), with a median hospital stay of 3 days. Most were admitted from Kabutare District Hospital (22%) to Internal Medicine (90%). Age distribution peaked at 61 years and above (38.8%) and 60 years and below (61.2%). Unemployment was high (83%), especially among females (60%) and those with low education. Prior 30-day hospitalization occurred in 34%, mainly for non-communicable diseases (41%) and infections (20%). Chronic conditions were reported by 41%, commonly hypertension (37%), other non-communicable diseases (14%), and diabetes (10%). Recent antibiotic use was 23%, primarily ceftriaxone (54%). Urine samples dominated (55%), with prevalent pathogens like Escherichia coli and Staphylococcus species. But more importantly this study demonstrated a strong association between nosocomial infection level and some predictors with significant P values as follows: time of stay (P=0.002), Health Care providers following WHO 5 Moments of hand hygiene (P=0.005), disinfection of medical devices by Health Care providers (P=0.036) and hands washing before taking medicines (P=0.047). Unique Contribution to Theory, Practice and Policy: The environmental decontamination and antibiotic rotation policies should be implemented to manage Acinetobacter spp. infections. As well hand hygiene adherence and preventive measures for urinary tract infections will address Escherichia Coli infections. Efforts to mitigate the burden of nosocomial infections should prioritize the enhanced surveillance, establishing robust infection tracking systems across healthcare facilities, invest in antimicrobial stewardship and targeted interventions tailoring infection control practices to high-risk groups like geriatric patients.

Transmission of MRSA, ESBL E. coli, and C. difficile within a tertiary care hospital and across surrounding facilities in Japan: a molecular epidemiological study with the PCR-based Open-reading frame typing.

To determine the regional impact of transmission of multidrug-resistant organisms (MRDOs) and Clostridioides difficile (C. difficile) among a tertiary care hospital and surrounding facilities including long-term care facilities (LTCFs). Retrospective cohort study. Patients admitted to a tertiary care hospital from July 2019 to July 2021 were recruited if their clinically collected cultures grew the following pathogens: Methicillin-resistant Staphylococcus aureus (MRSA), Extended-Spectrum Beta-Lactamase (ESBL) producing Enterobacterales, Pseudomonas aeruginosa with difficult-to-treat resistance, Carbapenem-resistant Enterobaterales, Vancomycin-resistant Enterococci, and C. difficile. Patient characteristics including admission and discharge pathway were collected. For the isolates of MRSA, ESBL-producing Escherichia coli (E. coli), and C. difficile, a molecular epidemiological analysis was conducted, utilizing the PCR-based Open-Reading Frame Typing (POT) method. Three hundred-five patients were identified with a total of 332 culture specimens of the target pathogens. The top three were 132 MRSA isolates (43.3%, out of 305), 97 ESBL E. coli (31.8%), and 32 ESBL Enterobacterales (non-E. coli) (10.5%). The target pathogens were more detectable within 3 days among patients admitted from LTCFs or other hospitals than those admitted from home (Odds Ratio 4.6, 95% confidence interval 2.8-7.6, p-value < 0.001). The molecular epidemiological analysis suggested the transmissions of MRSA, ESBL E. coli and C. difficile occurred 52 out of 111 patients within the in-hospital environment, and 7 out of 128 within the prehospital environment, respectively. MDROs/C. difficile transmission is prevalent within a tertiary care hospital and further complicated by its inter-facility transmission across surrounding LTCFs and hospitals in Japan.

Clinical characteristics of patients with granulomatous lobular mastitis associated with Corynebacterium parakroppenstedtii infection and drug sensitivity analysis of the isolated strains

BackgroundIt is presently considered that Corynebacterium especially Corynebacterium kroppenstedtii (CK) infection, is one of the important causes of granulomatous lobular mastitis (GLM). However, the pathogen of mastitis in the past two years has been identified as a newly discovered Corynebacterium. But it is unclear whether the pathogen associated with the occurrence of GLM is also this bacterium.MethodsGLM female patients with positive bacterial culture in pus specimens from February 2023 to February 2024 who were identified as CK infection by mass spectrometer were selected as the research objects in this study, and the clinical isolates were identified by 16S rDNA sequencing technology to identify the specific pathogen of GLM-related bacterial infection. Subsequently, the clinical characteristics of the patients were compared with those of GLM patients without bacterial infection during the same period, to explore the effect of this particular type of Corynebacterium infection on disease development in GLM patients. Finally, we tested the minimum inhibitory concentration (MIC) values of antibiotics when inhibiting these separation strains in vitro through the E-Test experiment, to evaluate their medicine sensitivity.ResultsA total of 31 GLM patients initially diagnosed with Corynebacterium kroppenstedtii (CK) infection via MALDI-TOF MS were enrolled in the study. However, subsequent 16S rDNA sequencing revealed that 28 isolates (90.32%) were actually identified as the newly recognized Corynebacterium parakroppenstedtii (CPK). This discovery challenges the conventional belief that CK is the primary pathogen of GLM, suggesting instead that CPK is the predominant pathogen associated with GLM bacterial infections. Comparative analysis of the clinical characteristics between the two groups revealed a significantly higher recurrence rate among CPK-infected GLM patients compared to those without CPK infection, along with elevated prolactin levels (P < 0.05). The sensitivity test results indicated high sensitivity of the isolates to vancomycin, linezolid, and rifampicin.ConclusionIn conclusion, this study highlights that Corynebacterium kroppenstedtii strains isolated from GLM specimens were Corynebacterium parakroppenstedtii, serving as the primary pathogen closely linked to GLM’s occurrence. CPK infection significantly increases the risk of recurrence in GLM patients, with elevated prolactin levels potentially playing a pivotal role in this process. In clinical antimicrobial treatment, antimicrobials other than penicillin and ciprofloxacin may be empirically administered when sensitivity test results are inconclusive.

Draft genome sequence of Nocardia sp. strain JMUB6875 isolated from a patient with disseminated nocardiosis.

We report the draft genome sequence of the Nocardia sp. strain JMUB6875, isolated from a blood culture specimen of a patient with disseminated nocardiosis. This strain appears to be a potentially novel species closely related to Nocardia concava.

Neglected Pulmonary Infection Caused by Exophiala dermatitidis Misidentified as Rhodotorula spp.

Exophiala dermatitidis is an emerging black fungus that causes pulmonary infections that may be underestimated by conventional culture methods. We encountered one case that initially appeared to be yeast and was misidentified as Rhodotorula spp. using a commercial identification kit. Thus, genetic identification and clinical background investigations were conducted on 46 strains of Rhodotorula spp. The sequences of the internal transcribed spacer and large-subunit RNA genes (D1/D2 regions) of 43 isolates, excluding two environmental isolates and one difficult-to-culture isolate, were determined and genetically identified. Notably, 22 isolates were identified as E. dermatitidis and misidentified as Rhodotorula spp. using the conventional method. Based on the exclusion criteria, the clinical information of 11 patients was retrospectively reviewed. Five cases (definite) had definite exacerbation of pulmonary infections due to E. dermatitidis, and six cases (possible) had undeniable infections. Of the 11 cases of pulmonary infection suggested to be caused by E. dermatitidis, comorbidities included two cases of chronic pulmonary aspergillosis (CPA), three cases of pulmonary non-tuberculous mycobacterial (NTM) infection and one case of pulmonary nocardiosis, suggesting a trend towards simultaneous detection of chronic pulmonary infections. Steroid and immunosuppressive drug use was observed in five cases, and β-D-glucan elevation was observed in three of five definite cases of pulmonary infections due to E. dermatitidis. The possibility of E. dermatitidis infection should be considered when Rhodotorula spp. are isolated from cultures of airway-derived specimens, and, in addition to CPA and NTM, identification of E. dermatitidis may be important in chronic pulmonary infections.

Acute Hematogenous Osteomyelitis in Pediatric Patients.

This article focuses on the advancements made in diagnostic techniques and drug interventions of acute hematogenous osteomyelitis. A diagnosis necessitates a combination of factors, including inflammatory markers and imaging findings, as well as the collection of specimens for culture when feasible. Subsequently, treatment should be based on epidemiology, mechanisms of resistance, and susceptibility findings. A brief course of intravenous (IV) antibiotics, followed by oral antibiotics, may be employed for uncomplicated infections if there is improvement in the clinical condition and a decline in C-reactive protein levels. However, for complex infections caused by methicillin-resistant Staphylococcus aureus, prolonged administration of IV antibiotics is recommended, along with surgical intervention if necessary. [Pediatr Ann. 2024;53(10):e392-e395.].

A 2-year comparative study of prevalence and antimicrobial resistance pattern of nonfermenting gram negative bacilli in ICU vs other units in a teaching hospital in Telangana

ABSTRACT Background: Nonfermenter bacteria which were previously considered as contaminants have now emerged as major cause of life-threatening healthcare-associated infections and as multidrug-resistant pathogens. Infections caused by them are predominantly secondary to some predisposing conditions like immunosuppression, burns, long-term antibiotic usage etc. Aim: The aim of this study was to determine the frequency and antimicrobial resistance pattern of Pseudomonas and Acinetobacter spp. by comparing the results from ICUs to other units at a teaching hospital in Telangana. Methods: A retrospective study over a 2-year period where all the nonfermenter GNBs isolated from various clinical samples sent to bacteriology section of microbiology department between 2022 and 2023 were collected. Results: During the period of study, a total of 263 nonfermenter GNBs were obtained out of 1792 IP-positive cultures accounting for 14.6% of their prevalence. Pseudomonas aeruginosa (182/263) 69% was the common NFGNB isolated followed by Acinetobacter baumanii (81/263) accounting to 31% of NFGNB. Most common culture specimen received from ICU was endotracheal aspirate (33%), whereas from other units, pus was the common specimen (45%). Overall antimicrobial resistance rate was less toward carbapenems 15% and 32% in both Pseudomonas aeruginosa and Acinetobacter baumanii, respectively. Conclusion: Our study shows high rate of NFGNB which raises the concern for rapidly emerging multidrug resistance. This requires the control of hospital environment and strict adherence to hand hygiene practices as well as rationale use of antibiotics by formulating the local antibiogram.

Does complete resection of infected bone improve clinical outcomes in patients with diabetic foot osteomyelitis?

The objective of the study was to compare outcomes in patients with complete surgical resection versus partial resection of diabetic foot osteomyelitis (OM). A post hoc analysis of 171 patients with OM was performed using data from two randomized clinical trials. OM was confirmed with bone culture or histopathology. Surgical culture specimens were obtained from resected bone and sent for histopathology and microbiology. Residual osteomyelitis (RO) was defined as a positive resected margin on culture or histopathology. No residual osteomyelitis (NRO) was defined as no growth from bone culture and no histopathological inflammation in the biopsy of the resection margin. Data from the 12-month follow-up were used to determine clinical outcomes. During the index hospitalization, NRO patients had significantly shorter duration of antibiotic therapy (NRO 21.0, 13.0-38.0 vs. RO 37.0, 20.8-50.0, p <0.01) and more amputations than patients with RO (NRO 89.9% vs. RO 60.9%, p <0.01). During the 12-month follow-up, patients with NRO also had significantly shorter duration of antibiotic therapy (NRO 42, 21.0-66.5 vs. RO 50.5, 35.0-75.0, p = 0.02). During the 12-month follow-up, there was no difference in ulceration at the same site (NRO 3.7%, RO 4.3% p = 0.85), hospitalization (NRO 32.6%, RO 34.8%, p = 0.76), total re-infections (NRO 25.3%, RO 29.3%, p = 0.56), re-infection with osteomyelitis (NRO 13.3% vs. 13.5%, p = 0.36), amputation (NRO 8.8%, RO 5.4%, p = 0.86) and time to wound healing in days (NRO 94, 41.0-365 vs. RO 106, 42.8-365, p = 0.77). Successful treatment of osteomyelitis was achieved by 86.7% and 86.5% of patients. During the index hospitalization, patients with no residual osteomyelitis had more amputations and were treated with antibiotics for a shorter duration. During the 12-month follow-up, patients with no residual osteomyelitis had shorter durations of antibiotics. There were no differences in re-infection, amputation, re-ulceration or hospitalization. Level of evidence: 1.