Bacterial Test Research Articles

Effect of Probiotic Lactobacillus Casei on Secretory Immunoglobulin A (S-IgA) Levels in Rats Norvegicus Strain Wistar Post Ovariectomy

Estrogen causes the growth of lactobacillus colonies in the vagina which convert glycogen in superficial vaginal cells into lactic acid, resulting in a low vaginal pH which can inhibit the invasion of pathogenic bacteria. After menopause, lactobacillus growth is inhibited, vaginal secretions become thin, vaginal pH increases and the immune system becomes low. This study aims to determine the effect of Lactobacillus Casei extract on secretory immunoglobulin A levels and reduce vaginal acidity levels (pH) and increase the number of beneficial bacteria in the vaginal mucosa. The research design used was an experimental study with a post-test-only control group design using 24 female rats aged 8-10 weeks with a weight of 180-220 grams. Before treatment, the rats were ovariectomized, and the acclimation period was 14 days, then divided into 4 groups, namely: (K) without treatment, P1 received Lactobacillus Casei extract at a dose of 2ml / rat, P2 at a dose of 2.25ml / rat, and P3 at a dose of 2.5ml / rat. Lactobacillus Casei extract was given orally for 14 days. On the 15th day all rats were terminated. Vaginal acidity levels were measured using the swab method and IgA was measured using the ELISA method, while for bacterial identification tests, gram-positive staining was performed. The results of the one-way ANOVA test showed that Lactobacillus Casei extract can increase IgA levels and significantly reduce vaginal acidity levels by p = 0.003 and p = 0.000. The decrease in acidity levels is due to the deordelin bacillus which converts glycogen into lactic acid so that the vagina remains acidic, as well as the role of S-IgA on the surface of the vaginal mucosa which functions as an opsonin and APC (antigen-presenting Cell) to inhibit the growth of pathogenic bacteria in the vagina. This study concludes that the administration of Lactobacillus Casei extract can increase secretory Immunoglobulin A (S-IgA) levels and reduce vaginal acidity (pH) to normal.

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.

Rapid diagnostic testing method to detect ROB β-lactamase gene in Neisseria meningitidis.

blaROB-1 is the only widely found β-lactamase in Neisseria meningitidis, and its presence is on the rise. To enhance our bacterial meningitis testing procedure, we clinically validated a real-time PCR assay to rapidly detect the blaROB gene and predict drug resistance in Neisseria meningitidis. A screen of 101 clinical isolates and 37 clinical specimens of blood and cerebrospinal fluid received between January 2018 and June 2024 found 8 isolates and 2 cerebrospinal fluid specimens that were positive for blaROB.

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-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

Pola Bakteri Aerob pada Sampel Sputum dan Uji Sensitivitas Antibiotik Pasien Rawat Inap di Rumah Sakit Dr. J.H Awaloei

Cough with phlegm is the most common medical complaint that leads to referral to a pulmonary specialist. Based on the World Health Organization (WHO) report that every year 4 out of 13 million deaths in developing countries are caused by respiratory tract infections, and at Dr. JH Awaloei Hospital, respiratory tract infections are ranked 4th out of 10 most common diseases. ARI can be treated with antibiotics if the microorganisms that cause it are bacteria, but the use of antibiotics must be in accordance with antibiogram data, rational and appropriate doses to prevent an increase in antibiotic resistance, because antibiotic resistance has become a chronic and global public health problem. Purpose: This study aims to identify aerobic bacterial patterns and antibiotic sensitivity tests in sputum samples of inpatients at Dr. J.H Awaloei Hospital. Methods: This study used a descriptive method with a cross sectional approach, namely by conducting bacterial pattern research on 15 samples, then cultured using nutrient agar and mac conkey at the Microbiology Laboratory of the Faculty of Medicine, Sam Ratulangi University. Results: Identification of bacteria by Gram staining. Antibiotic sensitivity test. The results of this study obtained Staphylococcus sp. (86.67%); Staphylococcus aureus (6.67%); Streptococcus sp. (6.67%). All bacteria were sensitive to the antibiotic Amikacin and resistant to Ampicillin and Clindamicin. The conclusion of this study is that the most bacteria found are Staphylococcus sp. which is most sensitive to Amikacin, Meropenem and most resistant to Ampicillin, Aztreonam, Clindamicin, Erythromycin.

Identifikasi Methicillin-Resistant Staphylococcus aureus pada Tenaga Kesehatan di Intensive Care Unit dan Instalasi Gawat Darurat RSU GMIM Pancaran Kasih Manado

Staphylococcus aureus is normal flora colonizing the anterior nares but may become pathogenic when the immune system is compromised. The increase and inappropriate use of antibiotics has resulted in Staphylococcus aureus becoming resistant to methicillin and other β-lactam antibiotics, known as Methicillin-Resistant Staphylococcus aureus (MRSA). MRSA-colonized healthcare workers can be a primary reservoir of MRSA, leading to transmission between healthcare workers and patients.This study aims to identify the presence of MRSA in healthcare workers in the ICU and emergency department of GMIM Pancaran Kasih General Hospital, Manado. Descriptive cross sectional study and total sampling, involving 20 healthcare workers. Nasal swab samples were cultured on MSA media, followed by bacterial identification and sensitivity testing with 30 μg cefoxitin antibiotic discs. A total of 11 samples (55%) of health workers were colonized with Staphylococcus aureus, and 4 samples (20%) were positive for MRSA. The conclusion of this study is that MRSA was found in health workers in the ICU and emergency room of RSU GMIM Pancaran Kasih Manado.

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.

Exploring the potential of tiger milk mushroom (Lignosus rhinocerotis) crude extracts as immunostimulants for Pacific white shrimp (Litopenaeus vannamei): effects on survival and immunological responses against Vibrio parahaemolyticus

ABSTRACT This study investigated the effects of tiger milk mushroom (Lignosus rhinocerotis) extract (LRE) on immune responses and resistance against the aquatic pathogen Vibrio parahaemolyticus in Pacific white shrimp (Litopenaeus vannamei) to improve disease management in shrimp aquaculture. LREs were extracted using methanol and water to evaluate their cytotoxicity and antimicrobial efficacy. L. rhinocerotis methanol extract (LRME) exhibited higher antimicrobial activity and lower acute toxicity compared to the aqueous extract, and was selected for subsequent in vitro hemocyte assays and in vivo feeding trials. The in vivo trials were conducted in two batches, with each batch consisting of five diets: a basal diet without LRME inclusion (control), a commercial diet, and three treatment diets supplemented with LRME at 1 g (LRME1), 5 g (LRME5), and 10 g (LRME10) per kilogram of feed. Each diet had three replicates (n = 3). The first batch included 120 shrimp with an average weight of 13.38 ± 1.72 g, and was used to evaluate immune parameters, including total hemocyte count (THC), hemocyte type proportions, phenoloxidase (PO) activity, phagocytic activity, and reactive oxygen species (ROS) production, over a 12-day feeding trial. The second batch consisted of 225 post-larvae (PL10) with an average weight of 0.06 ± 0.01 g, and was used for bacterial challenge tests to assess survival rates following a 4-day feeding trial. In the 12-day feeding trial, shrimp fed with LRME showed significant increases in THC, ROS production, phagocytic, and PO activity, with LRME1 consistently demonstrating substantial improvements across multiple immune parameters. Days 4 and 8 were observed as specific time points when LRME exhibited significant effects on shrimp immunity, highlighting the temporal nature of shrimp immune responses to LRME supplementation. In a subsequent bacterial challenge test, a 4-day supplementation of LRME1 significantly enhanced shrimp survival rates. This study highlights the potential of LRME in enhancing shrimp immunity and resistance against V. parahaemolyticus, with significant effects observed at 1 g kg−1 dietary inclusion and a supplementation period of 4 days.

Assessing the impact of different solvents in the bacterial reverse mutation test.

The bacterial reverse mutation test is essential for identifying the mutagenic potential of chemicals. The solubility of the test substance is vital for achieving the recommended assay concentration. Preferred solvents like dimethyl sulfoxide and water are chosen for their compatibility and historical data. Selecting a compatible solvent with Salmonella typhimurium and Escherichia coli WP2 uvrA strains, considering a maximum cytotoxic concentration or the limit of 5 mg/plate, can be challenging. This study assessed various solvents, including N,N-dimethylformamide, acetone, acetonitrile, ethyl acetate, 95% ethanol, diethylene glycol monomethyl ether, methanol, P-dioxane, tetrahydrofuran, and dimethylacetamide, as alternative solvents in the AMES test. Results showed all solvents, except tetrahydrofuran, were compatible at concentrations up to 100 μL/plate or more, as they did not inhibit S9 enzymes, bacterial growth, or alter bacterial revertant colony counts, making them suitable for the bacterial reverse mutation test.

Examining the effect of direct-from-blood bacterial testing on antibiotic administration and clinical outcomes: a protocol and statistical analysis plan for a pragmatic randomised trial

IntroductionPatients with suspected bacterial infection frequently receive empiric, broad-spectrum antibiotics prior to pathogen identification due to the time required for bacteria to grow in culture. Direct-from-blood diagnostics identifying the presence...

Neonatal conjunctivitis at a Brazilian tertiary center: the current relevance of Chlamydia trachomatis.

The microbiology pattern of neonatal conjunctivitis has changed over time, and the incidence of gonococcal conjunctivitis is almost nil. This study aimed to determine the etiology of neonatal conjunctivitis cases referred to a tertiary health center in Brazil. From 2017 to 2020, conjunctival swabs were taken from neonates with clinical signs of conjunctivitis and tested with bacterial culture and polymerase chain reaction for Neisseria gonorrhoeae and Chlamydia trachomatis. A total of 51 neonates were included in the 3-year study. Chlamydial conjunctivitis was diagnosed in 39 (76.5%) patients, and microbial growth was detected in 13 (25.5%) patients. The most isolated bacterium was Staphylococcus epidermidis (n=6, 11.8%), followed by other coagulase-negative Staphylococcus species (n=4, 7.8%) and S. aureus (n=2, 3.9%). One S. aureus isolate was resistant to oxacillin. There were no cases of gonococcal conjunctivitis. Ten (19.6%) patients showed polymerase chain reaction-negative C. trachomatis and negative bacterial culture test results. Findings show that C. trachomatis is the most common pathogen causing neonatal conjunctivitis. The high prevalence of C. trachomatis infection highlights the importance of screening and treating pregnant woman.

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.

A Six Years’ Trend Analysis of Antimicrobial Resistance Among Bacterial Isolates at Public Health Institute in Amhara Region, Ethiopia

Background: Antimicrobial resistance (AMR) is one of the top global threats to public health. This study determined trends in AMR from 2016 to 2021 in a regional research laboratory in Northwest Ethiopia.Methods: Data from 2016 to 2021 was extracted from a database. Bacterial identification and resistance tests were made using the standard microbiologic procedures. The results were described, trends in AMR were determined using polynomial regressions, and binary logistic regression at p value < 0.05 was used.Results: From 2016 to 2021, 25,143 specimens were sent for culture and susceptibility testing, among which 16,825 (66.9%) bacteria were isolated. About 12,528 (74.5%) isolates were gram‐negative, and 4297 (25.5%) were gram‐positive. Klebsiella pneumoniae (3783, 30.2%) and Escherichia coli (3199, 25.5%) were the most common gram‐negative bacteria, whereas coagulase‐negative Staphylococcus spp. (CoNS) (1765, 40.1%) and Staphylococcus aureus (1293, 30.1%) were the most common gram‐positive bacteria. The overall prevalence of AMR was 2738 (59.9%), of which about 1807 (66.0%) accounted for gram‐negative and 931 (34.0%) for gram‐positive bacteria. K. pneumoniae (743, 80.2%), Enterobacter cloacae (196, 74.8%), and Acinetobacter baumannii (213, 66.6%) were the most common resistant isolates among gram‐negative bacteria, while CoNS (406, 58%), Streptococcus species (34, 50%), and S. aureus (196, 37%) were from gram‐positive bacteria. About 571 (20.9%) of bacteria were resistant to 2–10 drugs. The overall trend of AMR has been rising from year to year, reaching a peak in 2019 which was approximately 66% and then after has been predicted to decline.Conclusion: AMR in the regional laboratory is prevalent and has been increasing although the quadratic equation has revealed downward‐opening parabola over time. A growing number of multidrug‐resistant bacteria are an alarm to awaken policymakers and those concerned to intervene before it is too late. This calls for a periodic, integrated, and continuing system to monitor AMR for commonly used antibiotics.

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.

Control of Vibrio parahaemolyticus in Seafood Using the Combination of Lytic Phages and Citric Acid.

Vibrio parahaemolyticus is a key foodborne pathogen in seafood that poses health risks to consumers. The application of phages and organic acids is considered an alternative strategy for controlling bacterial contamination in foods. In the present study, the genome features of five previously isolated virulent V. parahaemolyticus phages (VPpYZU64, VPpYZU68, VPpYZU81, VPpYZU92, and VPpYZU110) were characterized, and their bacteriostatic effects in combination with citric acid were analyzed. Genome sequencing of the five phages showed a total genome length of 76,153-144,768 bp. No virulent or drug-resistant genes were detected in the five phages. Bacterial inhibition testing of salmon fillets stored at 25 °C for 12 h showed that the number of V. parahaemolyticus decreased by 2.02 and 3.84 log CFU/g after treatment with a phage mixture, VPpMIx, and the combination of phage mixture VPpMIx and citric acid. In addition, phage VPpYZU64 combined with 600 μg/mL citric acid exhibited the highest biofilm reduction rate for V. parahaemolyticus. Collectively, our results show that combining phages and citric acid is a natural and efficient method of controlling V. parahaemolyticus growth in seafood.

Phytochemical Screening, Chemical Constitutions, and Antibacterial Activity for three Medicinal Plants Against Multidrug-Resistant Bacteria

Due to the importance of therapeutic plants in the production and preparation of drugs, The purpose of this study is to extract three medicinal plants, including seeds of Syzygium aromaticum “S. aromaticum”, leaves of Thymus vulgaris (T. vulgaris) and Myrtus communis (M. communis) using the steam distillation method. It evaluated their ability to inhibit pathogenic and antibiotic-resistant bacteria, including Staphylococcus aureus (S.aureus), Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E.coli) isolated from skin ulcers. Moreover, these extracts were cured to evaluate their phytochemicals and chemical constitutions using classical methods and Gc-mass spectroscopy. The phytochemicals results showed that the Flavonoids and terpenoids were observed in all samples, while the Alkaloids didn't appear. The extracts of S. aromaticum, T. vulgaris, and M. communis showed interesting compounds during the GC-mass spectroscopy test. It showed the presence of chemical compounds with active groups that could have a significant role in bacterial treatment, such as 9-octadecenamide, Caryophyllene, and Limonene. Moreover, The results of the bacterial test showed a high effectiveness of these oils on the types of bacteria used, especially S. aureus, and E. coli, where the highest results were for Myrtus on E. coli bacteria with an inhibition diam of 56 mm, while clove oil did not show any effectiveness against S. aureus, the inhibition zone diameter is zero. In general, the effectiveness of these essential oils against Gram N. P.aeruginosa was very weak compared to the effectiveness of these essential oils on other bacterial species used in the study, where the highest diameter of inhibition of these bacteria was by clove oil and reached 15 mm.