Bacterial Susceptibility Research Articles

Synergistic action of mucoactive drugs and phages against Pseudomonas aeruginosa and Klebsiella pneumoniae.

N-acetylcysteine (NAC) and ambroxol hydrochloride (AMB) are commonly prescribed alongside antibiotics to alleviate sputum retention in lower respiratory tract infections, which are often caused by bacterial pathogens. With the rising threat of antibiotic resistance, phage therapy has emerged as a promising alternative alongside. However, no studies have explored the potential interactions between phages and these mucoactive agents despite their frequent concurrent use during phage therapy. Therefore, investigating the potential synergy and its subsequent impact on phage infection dynamics could enhance clinical strategies for treating bacterial infections with phages. Our study utilized Pseudomonas aeruginosa strain ZS-PA-35 and Klebsiella pneumoniae strain Kp36, alongside their respective phages, to investigate their interactions in the presence of NAC or AMB. Our findings indicate that, under specific conditions, these mucoactive agents can function as adjuvants to lytic phages, enhancing bacterial susceptibility to phage infection and facilitating subsequent phage proliferation. Our study revealed that these synergistic interactions are strongly influenced by the physiological characteristics of the phages, the surrounding microenvironments, and the physiology of host tissues, as varying outcomes of phage-host interactions were observed among different phages and across distinct media. Taken together, our results emphasize the complexity of interactions between phages and NAC or AMB, underscoring the need for caution when using combination treatments.IMPORTANCEN-acetylcysteine (NAC) and ambroxol hydrochloride (AMB) are used in medical treatment of patients with acute and chronic bronchitis. Often, the choice of NAC or AMB is empirically determined by physicians. However, the potential impact of combining NAC or AMB with phage therapy remains unclear. To address this gap, a comprehensive understanding of their interplay is crucial to determine any potential synergistic effects. This study aims to elucidate how NAC or AMB influence phages targeting different receptors, thereby affecting their antibacterial activity against Pseudomonas aeruginosa and Klebsiella pneumoniae. Our results suggest that, under certain conditions, NAC or AMB provides an adjuvant effect by rendering the cells more susceptible to phage infection. These results contribute to advancing our understanding of the clinical combination of mucoactive agents and phage therapy, offering insights for optimizing treatment efficacy.

Antimicrobial Resistance Patterns in Pediatric Urinary Tract Infections: Insights from Hospitalized Children in Sudan

Introduction: Urinary tract infections (UTIs) are among the most common bacterial diseases in children, affecting 3–5% of girls and 1% of boys, and leading to significant antibiotic exposure in this population. Initial UTI treatment is often empirical, based on symptomatology without microbiological confirmation. Objective: This study aimed to identify the causative agents of UTIs in children, evaluate antimicrobial resistance rates, and recommend appropriate antibiotics. Materials and Methods: A cross-sectional study was conducted on 67 urine samples collected from hospitalized children at Gaafar Bin Ouf Children's Hospital in Khartoum, Sudan. Samples were processed for bacterial isolation, identification, and antimicrobial susceptibility testing using the Kirby-Bauer method. Results: Among the isolates, 24 (35.8%) were Staphylococcus aureus, 20 (29.9%) Klebsiella spp., 14 (20.9%) Escherichia coli, 8 (11.9%) Pseudomonas spp., and 1 (1.5%) Proteus spp. The highest resistance rates were observed for Amoxyclav (68.7%) and Erythromycin (61.2%), while Gentamicin (40.3%), Ciprofloxacin (43.3%), and Penicillin (46.3%) showed lower resistance rates. Conclusion: Staphylococcus aureus was the most common UTI pathogen in hospitalized children, with high resistance rates to Amoxyclav and Erythromycin. These findings highlight the need for regular resistance monitoring and revising empirical antibiotic protocols to improve treatment outcomes.

Epidemiological and genomic characterization of carbapenem-resistant Acinetobacter baumannii ST600 harbouring the blaNDM-1 gene, first report in Poland.

Acinetobacter baumannii (Ab) causes severe infections among intensive care units (ICU) and mechanically ventilated patients. According to the European Centre for Disease Prevention and Control data for 2018 the prevalence of Ab in Polish ICUs was higher than in other European countries, while almost 40% of Ab were resistant to carbapenems (CR-Ab) in 2021. Our goal was to investigate the epidemiology and molecular characteristics of CR-Ab strains collected from the University Hospital in Krakow, Poland, by whole-genome sequencing (WGS) and phenotypic tests. Epidemiological and drug-resistance data from a total of 667 hospital-acquired (HAI) CR-Ab infections collected in 2019 (442) and 2021 (235) were examined. Bacterial identification, antimicrobial susceptibility and detection of carbapenemases were performed. A selected subset of 125 CR-Ab isolated in 2021 was investigated by WGS. Among 125 CR-Ab isolates examined by WGS, the vast majority 104 (82%), belonged to the most prevalent ST2, and whereas 20 (16%) belonged to the rarely reported ST600. The most common genes conferring resistance to carbapenems were blaOXA-66 (96.8%), and blaOXA-72 (71.2%), whereas blaOXA-23 and blaNDM-1 genes were specific to ST600 isolates. The blaNDM-1 gene was chromosomally located in IS30 of Tn125. Our study reveals the presence of CR-Ab of the sporadically reported ST600 harbouring the blaNDM-1 gene, reported for the first time in Poland. Routine genomic surveillance should be implemented to monitor and reduce the transmission of circulating resistant Ab clones.

Potential Antibiotic Resurgence: Consecutive Silver Nanoparticle Applications Gradually Increase Bacterial Susceptibility to Antibiotics

Potential Antibiotic Resurgence: Consecutive Silver Nanoparticle Applications Gradually Increase Bacterial Susceptibility to Antibiotics

Measurement of antibiotic use in cats and dogs presenting to US primary care and referral practices provides insights for antimicrobial stewardship.

To measure the prevalence of antibiotic use in dogs and cats, identify the most common antibiotic drugs prescribed, and determine the most common indications for use. Point-prevalence survey methodology was used to collect antibiotic prescribing data for cats and dogs from 1 practice day in 2021 at nonacademic primary care and referral practices in the US. 52 practices participated, comprising records for 2,599 dogs and cats. Antibiotics were prescribed to 29.2% of animals, including 24.6% prescribed antibiotics for systemic and 6.3% for topical administration. The most common systemically administered antibiotics prescribed were aminopenicillins with beta-lactamase inhibitors (29.7%), imidazoles (16.4%), first-generation cephalosporins (15.9%), and third-generation cephalosporins (12.5%). Of the 810 clinical conditions associated with antibiotic prescriptions, the majority were skin (17.0%), gastrointestinal (15.9%), surgical (12.5%), otic (8.6%), ocular (8.5%), urinary (7.8%), and respiratory (7.3%). Dogs, inpatients, and animals presenting to referral practices were more likely to receive an antibiotic prescription. For the 478 dogs and cats prescribed an antibiotic intended to treat infection, 13.4% had bacterial culture and susceptibility testing. This study highlights areas for targeted antimicrobial stewardship efforts, including the limited use of bacterial culture and susceptibility testing, the frequent prescribing of third-generation cephalosporins and imidazoles, and the common use of prophylactic antibiotics for clean surgical procedures. Measurement of antibiotic use in companion animals is critical to focus antibiotic use guideline development, highlight the need for outcomes-based research, and identify barriers to engage in antimicrobial stewardship efforts.

P-1146. Environmental Surfaces in Healthy Households as Reservoirs of Extended-Spectrum Cephalosporin-Resistant Enterobacterales in the Community

Abstract Background Community-acquired extended-spectrum cephalosporin resistant (ESCr)-Enterobacterales (E) are increasing in healthy populations, yet the sources of acquisition are unknown. We assessed household (HH) environmental surface samples (HS) in St. Louis, MO, to identify the surfaces most frequently contaminated with ESCr-E and the associated mechanisms of antibiotic resistance (AR). Figure 1. Enterobacterales within households. Methods From 139 HHs, samples from 21 HS and inguinal fold (IF) samples of healthy adults and children were cultured for bacteria. Families were recruited from outpatient pediatric settings. Bacterial identification and antibiotic susceptibility testing were conducted (Vitek®2, bioMérieux). Molecular characterization of ESCr-E was performed by PCR detection of beta-lactamase (bla) and plasmid-mediated quinolone resistance (PMQR) genes. Whole genome sequencing (WGS) was performed on select HH with > 1 colonized HS to evaluate for genetic relatedness, plasmids, and AR genes. A HH cluster was defined as < 15 single nucleotide polymorphism differences between 2 isolates. Figure 2. ESCR Enterobacterales by genera Results Of 581 IF and 2801 HS, the majority harbored bacteria (IF, 97-100% and HS, 79-100%) and gram-negative bacteria, (IF, 72-80% and HS, 75-87%). IF colonization with Enterobacterales was ∼23% and ranged from 7-60% on HS; The most common ESCr-E genera were Enterobacter (79%), Pantoea (10%), and Klebsiella (7%). ESCr-E were found in 2% of IF. HS most notably colonized with ESCr-E were the kitchen sink faucet (9%), oven door handle (4%), sofa (4%), bathroom sink faucet (3%) and bed sheets (3%), (Figures 1-3). ESBL-E were recovered from ∼2% of HHs. MDR-E (> 3 antibiotic classes) were found in 4% of HHs. WGS of 20 E. cloacae from 4 HHs revealed within HH clusters (Figure 4). Of interest, we found that among E. cloacae, 10/20 (50%) contained AR plasmids (ex. IncFI, IncFII, IncX5, IncHI2, Col440I); bla, other AR (ex. PMQR, aminoglycoside, sulfa, fosfomycin) and virulence genes were detected in E. cloacae in all HHs. We also found related E. cloacae strains in 2 HHs (ST108), indicating local strains circulating potentially related to a common exposure. Figure 3. AR Enterobacterales by surface. Conclusion ESCr-E are present in healthy household environments. Future directions will be to identify candidate clinical and epidemiological features linked with ESCr-E HH colonization. Figure 4. Genetic relatedness among household Enterobacter cloacae Disclosures Ahmed Babiker, MBBS, Beckman Coulter Inc.: Advisor/Consultant

P-872. Clinical and Microbiological Trends in Citrobacter Bacteremia: A Study from South India

Abstract Background Citrobacter spp are anaerobic Gram-negative bacilli, accounting for approximately 0.8% of all Gram-negative infections. This study aims to elucidate the clinical manifestations and drug susceptibility in Citrobacter infections. Clinical features of patients with Citrobacter bacteremia and comparison between Citrobacter koseri and other Citrobacter spp Methods We conducted a retrospective analysis of Citrobacter spp. bacteremia cases from 2016 to 2022. We assessed clinical profile, species, antimicrobial susceptibility and 28-day outcome. Blood cultures were processed using the BacT/ALERT, Vitek 2 system was employed for bacterial identification and antimicrobial susceptibility testing and reported as per CLSI criteria. Isolates with intermediate susceptibility were classified as non-susceptible. Comparison of antibiotic susceptibility between C Koseri and other Citrobacter spp Results Over the 7 year study period, 25 cases of Citrobacter bacteremia were identified, 60% were males. The median age was 52.5 years (IQR: 46 – 75), with 2 pediatric cases. The annual incidence of Citrobacter bacteremia displayed an upward trend, from 12% in 2016 to 24% in 2022. C. koseri emerged as the predominant species (72%), followed by C. freundii (24%) and C. farmeri (4%). The majority of patients (72%) had diabetes, 16% had chronic liver disease, 12% had malignancy. Risk factors for Citrobacter bacteremia included the presence of an indwelling bladder catheter (76%) and a central venous catheter (44%). Urinary tract was the most frequent source (56%), followed by abdominal (20%) and soft tissue (8%); a newborn had meningitis with brain abscess. The mean for Pitt’s bacteremia score was 1.52±2.6. The mean Charlson’s co-morbidity index was 2.76±2.3. Clinical features for the entire cohort and comparative results between C Koseri and other Citrobacter spp (grouped as non-koseri) is depicted in figure 1. Ciprofloxacin susceptibility was higher among C koseri (94%) as compared to other spp (71%). Antibiotic susceptibility for ceftriaxone was almost similar between the 2 groups. Susceptibility rates for other antibiotics and comparison between C Koseri and other spp are shown in figure 2. All isolates were susceptible to ertapenem, imipenem and amikacin. The overall 28-day mortality rate was 12%. Conclusion We found C. koseri more commonly, urinary source as the most common source and device presence as a significant risk factor. Antibiotic susceptibility was better for C. koseri compared to others. 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-2111. Automated Bacterial Growth Detection, Bacterial Species Estimation and Antimicrobial Susceptibility Testing on Agar Plates Using a Light Transmission-based Monitoring System

Abstract Background Culturing bacteria on agar plates is essential for diagnosing bacterial infections, but it usually takes overnight and is labor-intensive. We have developed a novel device using a thin-film transistor image sensor to measure light transmission through agar plates every five minutes during incubation (Nakada et al. ASM 2023 and IDweek 2023). Here we present a proof of concept study for using this device for automated early detection and disk-diffusion susceptibility testing and compare the results to those obtained by experienced microbiology technicians. Methods Chromogenic agar plates were used for early detection and subsequent species estimation based on colony color changes, i.e. Enterobacteriaceae on CHROMagar mSuper CARBA plates and Staphylococci on MDRS-K plates. Statistical background subtraction was used for early detection of bacterial growth and histogram comparison of pseudo-color images created by correcting the intensity of red, blue, and green lights for species estimation. For disk diffusion tests susceptible and resistant E. coli and S. aureus were inoculated on Mueller-Hinton plates against the known agents and incubated for 18 hours with monitoring. Transmitted light images after 18 hours were first binarized and the distance of the shortest bacterial growth pixel from the center of the corresponding antibiotic disk was measured as the inhibition zone diameter. Results The device detected Enterobacteriaceae and MRSA as early as 6 and 8 hours after incubation, respectively, when the suspensions were densely streaked (Figure 1). The device also estimated the bacterial species with sensitivity and specificity over 90% for Enterobacteriaceae, however, the specificity for MRSA against MRCNS was approximately 70% (Table 1). An example of the automated inhibition zone measurement is shown in Figure 2. All automated measurements agreed well with the manual measurements (Table 2). Conclusion The performance in the bacterial detection, species estimation and the zone diameter measurement indicated that the device can be useful in accelerating, automating, and standardizing routine testing in microbiology laboratories. Disclosures Goh Ohji, MD, Ph.D, CarbGem Inc.: Advisor/Consultant Masakazu Nakajima, B. Engineering, CarbGeM Inc.: Board Member|CarbGeM Inc.: Ownership Interest

P-640. Vancomycin vs Ceftaroline for Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) Pneumonia: A Multicenter Retrospective Study

Abstract Background Vancomycin (V) is considered first-line treatment for MRSA infections, assuming bacterial susceptibility and patient tolerability. Ceftaroline (C) has been used off-label to treat MRSA blood stream infections, osteomyelitis, ventilator-associated pneumonia, hospital-acquired pneumonia and endocarditis. However, the efficacy of C vs V for treatment of MRSA pneumonia has not been studied.Figure 1.Summary of Exclusions for Patient Population Methods Data was extracted from a centralized database for 184 HCA Healthcare hospitals from January 1st, 2016 – June 30th, 2023. Patient encounters with a diagnostic code of MRSA pneumonia and received V and/or C were included for further analysis. In-hospital mortality and length of stay (LOS) were the main outcomes studied. Demographics including age, sex and race were extracted. Average vitals values noted included temperature and O2 saturation. Lab values included average WBC count, creatinine and GFR. Time to first dose of V or C from time of admission and time to transition from V to C were included. Patients who received C-only were combined with the patients who first received V and then transitioned to C (VC). IRB approval was obtained prior to data extraction.Table 1.Demographics, Clinical Data and Outcomes Results Initial data extraction yielded 5977 encounters with final analysis for 4511 unique patients. Encounters were excluded for missing demographic data, duplicates or when V or C were not received. The V-only group had 4372 encounters and the C+VC combined group had 139 encounters. The mortality rate in the V-only group was 609/4372 (13.9%), while that in the C+VC group was 31/139 (22.3%). LOS was 13.22 days and 18.45 days in the V only and C+VC groups, respectively. The average time to transition from V to C in the VC group was 6.4 hours with maximum of 34 hours. Average temperature and O2 saturation were not significantly different between the two groups. GFR (mL/min/1.73m2) was 63.86 and 60.30 and WBC (103/µL) count was 11.93 and 14.01 in the V and V+VC groups, respectively. Conclusion Preliminary data suggest that V may be superior to C for MRSA pneumonia with respect to mortality and hospital LOS. Average WBC may be greater in the C+VC group, suggesting more severe illness. Reasons for transition of V to C were unknown, however given the short transition time, the impact of V on treatment outcome is likely negligible. Disclosures All Authors: No reported disclosures

P-1252. Individualizing Antibiotic Therapy: Pharmacokinetic Approach to Evaluate and Optimize dosing of Meropenem in Critically Ill Sepsis Patients

Abstract Background The optimization of antibiotic dosing poses a considerable challenge, particularly in cases of Sepsis with acute renal impairment requiring continuous renal replacement therapy (CRRT). This study centers on the widely prescribed broad-spectrum beta-lactams, specifically meropenem, recognizing its extensive use in severe and complex clinical scenarios. The primary objectives of this study is to formulate new guidelines facilitating dose individualization, thus enhancing therapeutic outcomes for this critical population. Meropenem dosing recommendations for sepsis shock patients with acute renal impairment Methods Three studies were conducted based on specific hypotheses. The initial study involved a comprehensive systematic literature review aimed at critically evaluating the existing evidence regarding the dosing regimens of meropenem. Subsequently, Studies 2 and 3 were undertaken as observational, prospective, open-labeled, multicenter pharmacokinetic investigations within the Intensive Care Unit of a prominent tertiary care hospital in Coimbatore, India. The study cohort comprised thirty patients administered with meropenem experiencing septic shock with acute renal impairment requiring continuous renal replacement therapy. Population Pharmacokinetic models were meticulously developed, validated, and subjected to Monte Carlo simulations for comprehensive analysis. Results A comprehensive literature review exposed the limitations of current dosing recommendations, pointing to varied sickness severities, renal function levels, admission diagnostics, CRRT settings, and disparate pharmacokinetic (PK) methodologies. For meropenem, a crucial relationship between 24-hour urine output and total clearance emerged. Oligoanuric patients (< 100mL/24h) displayed a 30% decrease in total clearance compared to those with preserved diuresis ( >500mL/24h). Monte Carlo simulations supported tailored dosing recommendations, addressing bacterial susceptibility and patient diuresis status. Conclusion For optimal antibiotic dosing, our findings highlight the importance of considering clinical and demographic factors, including 24-hour urine output and patient weight. These insights can be implemented at the bedside to help navigate the complexities of antibiotic optimization within the Intensive Care Unit. Disclosures All Authors: No reported disclosures

Pola Bakteri Aerob dan Uji Kepekaan Antibiotik pada Urine Pasien dengan Kateter Uretra di RSU Gmim Pancaran Kasih Manado

Bacteria are prokaryotic organisms, many of which are part of the normal flora in the human body without causing infection. The infection pattern caused by this aerobic bacteria can very depending on factors such as the duration of catheter use, the patient’s health condition, and hygiene levels. Catheter-Associated Urinary Tract Infections (CAUTI) is one of the most common infections in the ICU and contribute to increased mortality and morbidity rates. Objective: To determine the aerobic bacterial patterns in urethral catheters and their antibiotic susceptibility at Pancaran Kasih General Hospital, Manado. Method: This study used a descriptive observational design with a cross-sectional approach to analyze the aerobic bacterial patterns and antibiotic susceptibility in the urine of patients with urethral catheters at GMIM Pancaran Kasih General Hospital, Manado. Results: Samples were taken from patients using urethral catheters, and 9 Gram-positive and 5 Gram-negative bacteria were identified, with Staphylococcus sp. being the most frequently found bacterium. Antibiotic susceptibility testing showed that Staphylococcus sp., Staphylococcus aureus, and Bacillus sp. were highly sensitive to two antibiotics: doxycycline and meropenem. Conversely, these bacteria showed resistance to several antibiotics, including chloramphenicol. Conclusion: Urethral catheter use revealed Staphylococcus sp. as the most frequently found bacterium. Antibiotic susceptibility testing showed that Staphylococcus sp., Staphylococcus aureus, and Bacillus sp. were sensitive to doxycycline and meropenem.

The Gut Bacteria of Gampsocleis gratiosa (Orthoptera: Tettigoniidae) by Culturomics

Gampsocleis gratiosa Brunner von Wattenwyl, 1862, is a type of omnivorous chirping insect with a long history of artificial breeding. It has high economic value and is also an excellent orthopteran model organism. In this study, 12 types of culture media combined with 16S rRNA sequencing were employed to isolate 838 bacterial strains from the gut of G. gratiosa. After sequence comparison, a total of 98 species of bacteria were identified, belonging to 3 phyla, 5 classes, 11 orders, 20 families, and 45 genera. Firmicutes and Proteobacteria accounted for the majority (92.86%). At the order level, Enterobacteriaceae, Bacillales, and Lactobacillales predominated (79.59%). At the genus level, Klebsiella (11.22%) and Enterococcus (7.14%) predominated. This study also enumerated the strain morphological, physiological and biochemical properties of 98 species of bacteria, including colony morphology, Gram staining, bacterial motility test, temperature gradient growth, pH gradient growth, citrate utilization test, temperature oxidase test, contact enzyme test, methyl red test, V-P test, indole test, gelatin liquefaction test, nitrate reduction test, hydrogen sulfide test, starch hydrolysis test, cellulose decomposition test, esterase (corn oil) test and antibiotic susceptibility testing. Additionally, 16 antibiotics were utilized to test the bacterial susceptibility of the strains. This study explored the types and community structure of some culturable microorganisms in the intestinal tract of G. gratiosa and recorded their physiological characteristics. These data reflect the physiological functions of the intestinal microorganisms of G. gratiosa and provide support for subsequent research on the interaction mechanism between microorganisms and their hosts.

Pathogenic characterization and drug resistance of neonatal sepsis in China: a systematic review and meta-analysis.

Neonatal sepsis is one of the causes of neonatal mortality and bacterial resistance to antibiotics is one of the challenges facing NICU. The aim of this study was to provide a basis for empirical antibiotic selection by comprehensively searching Chinese and non-Chinese databases for studies related to neonatal sepsis pathogenesis conducted in China and synthesizing all the results of the studies conducted in hospitals in China during the period under study METHODS: In this study, we conducted extensive searches of Pubmed, Web of Science, Cochrane, China Biology Medicine disc (SinoMed), China National Knowledge Infrastructure (CNKI) and Wanfang Data. We screened studies published from 2014 to 2023 that were conducted in hospitals in mainland China and involved bacterial blood cultures and susceptibility tests in neonates with neonatal sepsis and extracted the data, which were summarized using Stata 18.0 software to determine the bacterial characteristics of NS and its antimicrobial resistance in China. A total of 97 articles were finally included in the study, involving 27 provinces, municipalities and autonomous regions, and a total of 18,796 bacterial strains were isolated. Among them, Gram-positive bacteria (G+) accounted for 63.4% (95% CI 59.6%~67.3% ), and Gram-negative bacteria (G-) accounted for 36.6% (95% CI 32.7%~40.4%). The most common bacteria were, in order, Coagulase-negative Staphylococcus (43.6%, 95% CI 37.9-49.3%), Enterobacter (16.4%, 95% CI 14.8-18.1%), and Klebsiella (12.4%, 95% CI 10.8-14.0%). More than 80% of G + were resistant to penicillin, ampicillin, and benzathine, and no strains resistant to minocycline or daptomycin were found. More than 80% of G- were resistant to benzoxicillin, ampicillin, and cefotaxime, and no strains resistant to vancomycin, clindamycin, tigecycline, teicoplanin, and linezolid were identified. Coagulase-negative Staphylococcus is still the main causative agent for children with neonatal sepsis in China, followed by Enterobacter and Klebsiella. In addition, Group B Streptococcus is no longer in the top three common causative agents. Resistance to penicillin antibiotics is evident among the causative organisms of neonatal sepsis in China.

Unveiling the role of BON domain-containing proteins in antibiotic resistance.

The alarming rise of antibiotic-resistant Gram-negative bacteria poses a global health crisis. Their unique outer membrane restricts antibiotic access. While diffusion porins are well-studied, the role of BON domain-containing proteins (BDCPs) in resistance remains unexplored. We analyze protein databases, revealing widespread BDCP distribution across environmental bacteria. We further describe their conserved core domain structure, a key for understanding antibiotic transport. Elucidating the genetic and biochemical basis of BDCPs offers a novel target to combat antibiotic resistance and restore bacterial susceptibility to antibiotics.

Retention and Caries Preventive Effects of Glass Ionomer and Resin Sealants in School-Aged Children: A Comparative Clinical Study

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Clinical Profile and Antibiotic Susceptibility Patterns of Cronobacter sakazakii in the Northern Region of Oman

Abstract Background: Cronobacter sakazakii is an opportunistic pathogen that mostly affects neonates, infants, and elderly people with weakened immune systems. No study has reported the frequency and antibiotic susceptibility patterns of C. sakazakii from Oman, and thus this study was conducted to fill this gap in the literature. Materials and Methods: This single-center retrospective study included C. sakazakii isolates identified from different clinical samples of patients treated at Sohar Hospital, Oman, between January 2017 and December 2023. Bacterial identification and antibiotic susceptibility testing were done using the VITEK II automated microbiological system in accordance with the Clinical Laboratory Standards Institute (CLSI) guidelines. Results: A total of 185 C. sakazakii isolates were included, most commonly from patients aged >60 years (42.7%) and <1 year (11.4%). C. sakazakii strains had high susceptibility (>80%) to most of the tested antibiotics; however, for beta-lactam antibiotics, it ranged from 0% to 50%. Approximately 26.5% of the strains were multidrug resistant. Independent risk factors for increased frequency of multidrug-resistant strains were urinary catheterization (P = 0.002), surgery (P = 0.021), previous antibiotic therapy (P = 0.047), and critical care unit admission (P = 0.048). About one-fifth of the patients experienced life-threatening C. sakazakii infections such as septicemia (15%) and pneumonia (4.7%). All deaths due to septicemia occurred in the >60 years (n = 12) and <1 year (n = 4) age groups. Conclusions: Cronobacter sakazakii isolates from the North Batinah region of Oman were most frequently isolated from elderly and infant patients and had high antibiotic susceptibility; however, the significant resistance against beta-lactams suggests their low effectiveness. The high number of multidrug-resistant strains coupled with the independent risk factors suggests the need for following stricter antibiotic stewardship protocols and infection control practices.

Detection of O25b-ST131 clone in extended spectrum beta-lactamase-producing E. coli from urinary tract infections in Mexico.

Escherichia coli has emerged as an important pathogen in urinary tract infections (UTIs) due to the rapid acquisition of antibiotic resistance genes. This enhances the ability of E. coli to colonize and creates therapeutic challenges within the healthcare system. This study aimed to identify the extended spectrum beta-lactamase (ESBL) and O25b-ST131 pandemic clones in E. coli isolated from two hospitals in Mexico. Bacterial identification and antibiotic susceptibility tests were conducted using the VITEK 2 system. The ESBL and plasmid-mediated quinolone resistance (PMQR) genes were identified by polymerase chain reaction (PCR). E. coli genotyping was carried out by the phylogenetic group analysis and O25b-ST131 identification. A total of 103 unique E. coli clinical isolates were analyzed from a pool of 1,002 strains; 75% obtained from UTIs and vaginal secretions. Multi-resistant antibiotic profiles were observed. Notably, the presence of the aac(6`)lb-cr and qnr genes was associated with 100% ciprofloxacin resistance, when ESBL was present. Additionally, the B2 phylogenetic group was identified, with 23% of isolates belonging to the O25b-ST131 clone. Our research revealed a 10% prevalence of ESBL, in contrast to global prevalence rates. The resistance profiles suggest that the effectiveness of these commonly used antibiotics in treating E. coli-associated UTIs or vaginal infections has decreased significantly. Excessive use of antimicrobial agents contributes to the regional variation. Our results underscore the importance of monitoring the molecular epidemiology, antibiotic resistance, and transmission dynamics of the O25b-ST131 E. coli clone.

Assessment of bacterial isolates and antimicrobial susceptibility patterns in external ocular infections among patients attending eye clinic at Kafrelsheikh University Hospitals.

Ocular infections can harm the eye's anatomic structure on numerous levels. They are a global health issue. Endophthalmitis, a serious complication following cataract surgery, can result in substantial ocular morbidity and vision loss despite the administration of antibiotics. Bacterial ocular flora are the primary causative agents. This study aimed to assess the types of bacterial isolates on the external ocular surface and evaluate their antimicrobial susceptibility patterns in pre-operative cataract patients at Kafrelsheikh University Hospitals. This cross-sectional study enrolled 691 patients scheduled for routine cataract surgery in the Department of Ophthalmology at Kafrelsheikh University Hospitals, Egypt. Each patient underwent a comprehensive assessment of medical history, including the use of traditional medicine, past eye trauma, and any prior eye surgeries, as well as ophthalmic clinical data such as visual acuity and ocular surface disorders. Conjunctival swabs were collected and processed using standard microbiological procedures to identify bacterial isolates and their respective antimicrobial susceptibility patterns. Among the 691 patients enrolled (median age 60 years, IQR 54-66), 59.8% were female. Conjunctival cultures yielded positive results in 38 cases (5.6%). The most frequently isolated organisms were Staphylococcus aureus, accounting for 52.6% of isolates, followed by Staphylococcus epidermidis at 15.8%. Notably, S. aureus demonstrated the highest resistance to erythromycin and vancomycin, with all 20 isolates showing resistance. In contrast, linezolid exhibited high efficacy, with 19 isolates showing sensitivity and only one displaying resistance. This study indicated that ocular conditions such as dry eye syndrome, Meibomian gland dysfunction, and scaly blepharitis are strongly associated with the prevalence of culture-confirmed ocular infections. Regarding antibiotic susceptibility, most Staphylococcus species demonstrated the greatest sensitivity to linezolid and trimethoprim/sulfamethoxazole.

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

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