Β-lactamase Production Research Articles

Production of AmpC β-Lactamase and Development of a Competitive Array for Discriminative Determination of Cephalosporins in Milk.

In this study, AmpC β-lactamase of Escherichia coli was expressed, and its intermolecular interaction mechanisms with 15 cephalosporins (CPs) were studied by using a molecular docking technique. Results showed that this enzyme mainly interacted with the β-lactam ring of these CPs, and the key contacting amino acids were Ser80 and Ser228. The AmpC β-lactamase was combined with 5 horseradish peroxidase-labeled conjugates to develop a direct competitive array on a microplate for determination of 15 drugs in milk. Due to the use of principal component analysis method to analyze the data, this method could discriminate the 15 drugs at the concentration as low as 10 ng/mL. The detection results for the unknown milk samples were consistent with those obtained by the liquid chromatography-mass spectrometry method. As a general comparison, this method is better than the previous antibody-based and receptor-based detection methods for CPs. This is the first paper reporting a competitive array for discriminative determination of a class of small-molecule substances.

2473. Rates of Antibiotic Resistant Infections in Hospitalized Patients with Hematologic and Non-Hematologic Cancers, 2019

Abstract Background Patients with cancer have risk factors for developing both hospital-onset (HO) and antibiotic resistant (AR) infections such as high antibiotic use, long lengths of stay, and device utilization. Understanding the epidemiology of AR infections in this population can inform clinical management and prevention strategies. We aimed to describe the rates and proportions of AR infections in hospitalized patients with cancer. Methods Using the PINC AI Healthcare Database, we included adult discharges from 2019 among facilities reporting microbiology data. We identified patients with at least one cancer diagnosis from the Healthcare Cost and Utilization Project’s Clinical Classifications Software Refined categories and Elixhauser Comorbidity Software Refined for ICD-10-CM. We calculated age-standardized rates of AR infections among cancer patients per 10,000 discharges, stratified by community-onset (CO: ≤ day 3 of hospitalization) and HO (≥ day 4 of hospitalization), and hematologic and non-hematologic cancer types. Hematologic cancers included lymphoma, leukemia, myeloma and myelodysplastic syndrome. We also examined the proportion of AR infections in patients with cancer among all AR infections in the cohort. Results Of >2 million discharges from 277 facilities, 11.4% were patients with cancer. Compared to all patients, cancer patients had higher rates of infection with CO and HO vancomycin resistant Enterococcus (VRE) and carbapenem resistant Enterobacterales (CRE), and HO Enterobacterales with AR phenotypes suggestive of extended-spectrum β-lactamase (ESBL) production (Table 1). Compared to patients with non-hematologic cancer, patients with hematologic cancer had higher rates of all AR infections, except for CO carbapenem resistant Acinetobacter spp. (CRAsp) infections (Table 1). For most AR infections, cancer patients made up a greater proportion of all HO AR infections compared to CO AR infections (Table 2). Conclusion Patients with cancer had higher rates of several AR infections compared to all patients. To decrease the burden of AR infections in this population, infection prevention strategies may focus on VRE, ESBL, and CRE pathogens, as well as HO infections, in all cancer patients, particularly those with hematologic cancer. Disclosures All Authors: No reported disclosures

1933. Characteristics of Community-Associated Extended-Spectrum β-Lactamase Producing Enterobacterales Infections in Monroe County, NY, 2020-2021

Abstract Background Extended-spectrum β-lactamase–producing Enterobacterales (ESBL) have emerged as a serious multidrug resistant threat to the community. Epidemiologic data for community-associated (CA) ESBL infections are limited compared to that for healthcare-associated (HA) infections. We examined characteristics of CA ESBL cases over a two-year period and compared them to those of HA cases to guide prevention. Methods CA ESBL cases from 1/2020-12/2021 were identified via laboratory and population-based surveillance in Monroe County as part of the CDC Emerging Infections Program. Cases were defined as the first instance of positive culture in a county resident from a normally sterile site or urine of Escherichia coli, Klebsiella pneumoniae, or K. oxytoca resistant to ≥ 1 3rd-generation cephalosporin and nonresistant to carbapenems. Epidemiologic data were collected through medical record abstraction. Cases were classified as HA if they had prior healthcare exposures (e.g. hospitalization, surgery, chronic dialysis, indwelling devices, or external catheters) and CA if they did not. Case addresses were geocoded to the census tract level to obtain Social Vulnerability Index (SVI) percentiles. Chi-square analyses were conducted to quantify the difference in distribution of these characteristics between CA and HA cases. Results From 2020-2021, 1729 incident cases were identified; 854 (49%) were classified as CA. Compared to HA cases, CA cases were younger (median 59 vs. 70 years), more likely to be female (89.8% vs 65.3%), less likely to have a urinary tract abnormality (27.0% vs 56.8%) or underlying comorbidities (73.2 % vs 95.8%), and less likely to have received prior antibiotics (24.0% vs 55.1%). Interestingly, CA cases were more widely spread across SVI quartiles compared to HA cases; a higher proportion of HA cases resided in census tracts in the 3rd or 4th SVI quartiles (Table 1). Conclusion Patient-specific risk factors classically associated with HA ESBL are less commonly associated with CA ESBL in Monroe County. Community-based preventions may need to target different populations than hospital-based strategies. As ESBL incidence increases, continued surveillance to identify at-risk groups and explore the association of specific social determinants of health is necessary. Disclosures Rebecca Tsay, MPH, CDC: Grant/Research Support Ghinwa Dumyati, MD, Pfizer: Grant/Research Support

Presence of the blaTEM Gene in Commensal Neisseria spp.: A Possible Cause for the Acquired Drug Resistance Among Pathogenic Respiratory Bacteria.

Background The oral microbiome consists of various bacterial genera, withNeisseriaspp. being a prominent part of this niche. WhileNeisseria gonorrhoeaeandNeisseriameningitidisare human-restricted pathogens, non-pathogenicNeisseriaspecies likeNeisseria sicca,Neisseria perflava, etc.,are primarily commensals that can also behave as opportunistic pathogens. With increasing penicillin resistance in commensalNeisseria, there is a concern that these bacteria might harbor resistance genes that can be transferred to other pathogens. This study aimed to characterize the blaTEM gene (encodes for the plasmid-mediated β-lactamase enzyme that hydrolyzes the β-lactam ring) of commensalNeisseriaspp. isolated from respiratory samples. Methodology The research was conducted in the Department of Clinical Microbiology at Sri Ramachandra University, Chennai. The specimens used were sputum and throat swabs, which were subjected to a series of phenotypic methods and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) for speciation. The antibiogram was determined using the Kirby-Bauer disk diffusion method, and a PCR assay was utilized to identify theblaTEMgene responsible for β-lactamase production. Results Out of 274 processed samples, 65 unique commensalNeisseriaspp. were identified. The study highlighted the presence of theblaTEMgene in 93.9% (61) of the isolates, which is responsible for β-lactamase production. All isolates exhibitedresistance to penicillin. MostblaTEM-positive commensalNeisseria spp. were susceptible to cefuroxime (83.6%), ceftriaxone (85.2%), and cefotaxime (85.2%). The high prevalence of theblaTEMgene in commensalNeisseriais alarming. The gene, found on plasmids, could potentially transfer to other related species likeNeisseria gonorrhoeaeandNeisseriameningitidis, as well as other Gram-negative bacilli. Conclusion The presence of resistance genes in commensal bacteria is of concern, as they might be reservoirs for resistance transfer to pathogenic strains. The study emphasizes the importance of continuous monitoring and deeper investigations into commensal bacteria, emphasizing the need for a broader community screening approach to understand resistance mechanisms in the normal microbiome.

Prevalence of Extended Spectrum β-Lactamase Producers (ESBLs) with antibiotic resistance pattern of Gram negative pathogenic bacteria isolated from door handles in hospitals of Pokhara, Western Nepal

BackgroundThe presence of drug-resistant Gram-negative pathogenic bacteria and Extended Spectrum β-Lactamase Producers (ESBLs) in hospital associated fomites like door handles can serve as vehicles in transmission and may be the key factor in epidemiology of ESBL producing bacterial infection not only in a hospital setting but also in the community. The aim of this study was to determine the prevalence of ESBLs and antibiotic resistance of Gram-Negative pathogenic Bacteria isolated from door-handles in two selected hospitals in Pokhara Metropolitan City, Nepal. The study was conducted in selected hospitals in Pokhara Metropolitan City, Western Nepal. A cross-sectional study design was used. The hospitals were selected randomly. A total of 100 swab samples were taken from door-handles. Isolation and identification of bacteria were done using standard microbiological procedures. An antibiotic susceptibility test, screening and confirmation of ESBLs were performed using the Clinical Laboratory Standard Institute’s guidelines. ResultsOut of the 100 swab samples cultured, 96 (96%) showed bacterial growth. A total of one hundred and forty isolates were isolated in this study which were further identified based on cultural, morphological and biochemical characteristics. The study also found that door handles/knobs had higher level of contamination in Outpatient Departments (OPDs), Emergency, Laboratory, General wards and Toilets, in that order as compared to Radiology Room, Staff rooms, Intensive Care Unit and Operation Theatre which were lower. The level of contamination varies depending on the traffic exposure and the environment. The most prevalent Gram-negative bacteria identified was Escherichia coli 28.85%, followed by Klebsiella spp 21.15%, Pseudomonas aeruginosa 15.38%, Proteus spp 11.54%, Enterobacter spp 9.62%, Acenetobacter spp 7.69%, Citrobacter spp 5.77%. The most effective drug of choice was Amikacin, Nitrofurantoin, Norfloxacin, Ciprofloxacin, Tetracycline and Imipenem for many Gram-negative isolates. The overall prevalence of ESBLs in this study was 27.14%. Out of total 15 Escherichia coli isolated, 11(73.3%), Klebsiella spp 9/11 (81.8%); Pseudomonas spp 7/8 (87.5%), Proteus spp 4/6 (66.6%); Enterobacter spp 3/5 (60%), Acenetobacter spp 3/4 (75%) and Citrobacter spp 1/3 (33.3%) were found to be Extended β-Lactamase Producers (ESBLs). ConclusionThe isolation of of pathogenic Gram-negative bacteria and ESBLs in hospital environments and subsequent detection of high drug resistance patterns indicates a potentially serious public health challenge that strengthens the need for the effective and routine cleaning of door-handles in hospitals.

Detection of FOX-AmpC-β-lactamase gene and antibiogram of AmpC-beta-lactamase-producing pathogens isolated from chronic suppurative otitis media patients in Nigeria.

AmpC-producing Gram-negative bacterial (GNB) pathogens are distributed worldwide, especially in clinical settings. This study aimed to determine the antibiogram and the type of AmpC-β-lactamase gene harboured by GNB pathogens implicated in chronic suppurative otitis media (CSOM) cases. Ear swab samples (300) collected from patients with active CSOM were analysed using standard microbiological techniques. Phenotypic and molecular detection of AmpC β-lactamase production was done by cefoxitin/cloxacillin double-disk synergy test and PCR respectively. Antibiogram was determined by disk diffusion technique. Among the GNB pathogens isolated from CSOM patients, P. aeruginosa was the most predominant (36.3%); followed by K. pneumoniae (22.3%), and E. coli (13.7%). Patients with active CSOM showed increased bacteria isolation rate from bilateral ear discharges than unilateral ear discharges. E. coli and P. aeruginosa were more prevalent among patients with duration of discharge >2 weeks; recording 9.0% and 20.3% respectively. AmpC β-lactamase producers accounted for 14.0%; they were highly resistant (60%-100%) to cephalosporins, trimethoprim-sulfamethoxazole, ofloxacin, amoxicillin, and tetracycline, but very susceptible (70.4%-100%) to ciprofloxacin, imipenem, and amikacin. Multiple antibiotic resistance indices of isolates ranged from 0.7-0.8. FOX-AmpC-β-lactamase gene was detected in 3.9% of the isolates. The detection of AmpC β-lactamase-producing multidrug-resistant GNB pathogens harbouring FOX-AmpC-β-lactamase gene among patients with CSOM infections in our study is a serious public health problem which needs urgent intervention.

Antibiotic prophylaxis and hospitalization of horses subjected to median laparotomy: gut microbiota trajectories and abundance increase of Escherichia.

Horse clinics are hotspots for the accumulation and spread of clinically relevant and zoonotic multidrug-resistant bacteria, including extended-spectrum β-lactamase producing (ESBL) Enterobacterales. Although median laparotomy in cases of acute equine colic is a frequently performed surgical intervention, knowledge about the effects of peri-operative antibiotic prophylaxis (PAP) based on a combination of penicillin and gentamicin on the gut microbiota is limited. We collected fecal samples of horses from a non-hospitalized control group (CG) and from horses receiving either a pre-surgical single-shot (SSG) or a peri-operative 5-day (5DG) course of PAP. To assess differences between the two PAP regimens and the CG, all samples obtained at hospital admission (t0), on days three (t1) and 10 (t2) after surgery, were screened for ESBL-producing Enterobacterales and subjected to 16S rRNA V1-V2 gene sequencing. We included 48 samples in the SSG (n = 16 horses), 45 in the 5DG (n = 15), and 20 in the CG (for t0 and t1, n = 10). Two samples of equine patients receiving antibiotic prophylaxis (6.5%) were positive for ESBL-producing Enterobacterales at t0, while this rate increased to 67% at t1 and decreased only slightly at t2 (61%). Shannon diversity index (SDI) was used to evaluate alpha-diversity changes, revealing there was no significant difference between horses suffering from acute colic (5DG, SDImean of 5.90, SSG, SDImean of 6.17) when compared to the CG (SDImean of 6.53) at t0. Alpha-diversity decreased significantly in both PAP groups at t1, while at t2 the onset of microbiome recovery was noticed. Although we did not identify a significant SDImean difference with respect to PAP duration, the community structure (beta-diversity) was considerably restricted in samples of the 5DG at t1, most likely due to the ongoing administration of antibiotics. An increased abundance of Enterobacteriaceae, especially Escherichia, was noted for both study groups at t1. Colic surgery and PAP drive the equine gut microbiome towards dysbiosis and reduced biodiversity that is accompanied by an increase of samples positive for ESBL-producing Enterobacterales. Further studies are needed to reveal important factors promoting the increase and residency of ESBL-producing Enterobacterales among hospitalized horses.

Inhibition and Reduction of Biofilm Production along with Their Antibiogram Pattern among Gram-Negative Clinical Isolates.

Bacterial biofilm is a significant virulence factor threatening patients, leading to chronic infections and economic burdens. Therefore, it is crucial to identify biofilm production, its inhibition, and reduction. In this study, we investigated biofilm production among Gram-negative isolates and assessed the inhibitory and reduction potential of ethylene diamine tetra acetic acid (EDTA) and dimethyl sulfoxide (DMSO) towards them. In addition, we studied the antimicrobial resistance pattern of the Gram-negative isolates. Bacterial isolation and identification was done using standard microbiological techniques, following the Clinical and Laboratory Standards Institute (CLSI) guideline, 28th edition. The Kirby-Bauer disk diffusion method was used to determine the antibiotic susceptibility pattern of the isolates, and β-lactamase production was tested via the combination disk method. Biofilm formation was detected through the tissue culture plate (TCP) method. Different concentrations of EDTA and DMSO were used to determine their inhibitory and reduction properties against the biofilm. Both inhibition and reduction by the various concentrations of EDTA and DMSO were analyzed using paired t-tests. Among the 110 clinical isolates, 61.8% (68) were found to be multidrug resistant (MDR). 30% (33/110) of the isolates were extended-spectrum β-lactamase (ESBL) producers, 14.5% (16/110) were metallo-β-lactamase (MBL), and 8% (9/110) were Klebsiella pneumoniae carbapenemase (KPC) producers. Biofilm formation was detected in 35.4% of the isolates. Biofilm-producing organisms showed the highest resistance to antibiotics such as cephalosporins, chloramphenicol, gentamicin, and carbapenem. The inhibition and reduction of biofilm were significantly lower (p < 0.05) for 1 mM of EDTA and 2% of DMSO. Isolates forming biofilm had a higher resistance rate and β-lactamase production compared to biofilm nonproducers. EDTA and DMSO were found to be potential antibiofilm agents. Hence, EDTA and DMSO might be an effective antibiofilm agent to control biofilm-associated infections.

High oral carriage of multidrug resistant Gram-negative bacilli in adolescents: the SOPKARD-Junior study.

The colonization of the oral cavity by potentially pathogenic antimicrobial-resistant bacteria in adolescents and its consequences is very poorly understood. The present study focused on the occurrence of oral colonization by Gram-negative bacilli (GNB) and their multidrug resistance, including the production of extended-spectrum β-lactamases (ESBLs) and carbapenemases, among healthy adolescents and risk factors associated with GNB colonization. This study was conducted as part of "A program for the early detection of risk factors for lifestyle diseases SOPKARD-Junior" (SOPKARD-Junior). Oral samples were collected from 182 adolescents from four public elementary schools in Sopot, Poland, aged 13-14 years. Bacterial strains were identified by the MALDI-TOF MS method. Screening of antimicrobial resistance was performed using a disk diffusion method. The NG-Test® CARBA-5 was used to detect and differentiate the five most widely distributed carbapenemases. Demographic and clinical data were collected and statistical analysis of risk factors was performed. A total of 68 out of 182 (37.4%) healthy adolescents was documented oral colonization with Gram-negative bacilli, including 50/182 (27.5%) multidrug resistant (MDR-GNB) strains. Over 60% of oral carriage concerned three main genera Enterobacter spp., Pseudomonas spp., and Serratia spp., which were detected in 22.1%, 19.1%, and 19.1% of participants, respectively. Citrobacter spp., Escherichia coli, Klebsiella spp., Hafnia spp., Aeromonas spp., Acinetobacter spp., and Stenotrophomonas spp. were also isolated. The antimicrobial resistance to ampicillin (100%), ceftazidime (69.1%), meropenem (60.3%), gentamycin (60.3%), piperacillin/tazobactam (52.9%), and piperacillin (45.6%) were the most common. Among 73.5% GNB strains multidrug resistance was observed, including all Pseudomonas spp. strains. Among MDR-GNB, 30.4% were resistant to four groups of antibiotics, half of the MDR Pseudomonas spp. strains were resistant to 10 groups of antibiotics. Extended-spectrum β-lactamases were produced by Enterobacter cloacae, Klebsiella spp., and Serratia spp. (7.4%). Colonization by ESBLs-positive GNB strains was significantly associated with recurrent respiratory infections, nasal congestion, and bronchitis (p<0.05). Our study revealed high oral carriage of multi-drug resistant Gram-negative bacilli in healthy adolescents and the association of ESBL-producing strains with respiratory infections. Further studies on oral colonization with GNB are necessary due to the possibility of distinct infections and the acquisition of antibiotic resistance by resident microbiota.

Changes in antimicrobial resistance of Staphylococcus aureus in bovine quarter milk samples from southern Germany between 2012 and 2022

The objective of this study was to describe the in vitro resistance of Staphylococcus aureus from bovine quarter milk samples obtained by the udder health laboratory of the Bavarian Animal Health Services between 2012 and 2022. All S. aureus samples were tested for β-lactamase production and only forwarded to further microbroth susceptibility testing either if the β-lactamase result was positive or upon explicit request by the submitter. The growth of most S. aureus isolates was inhibited at the lowest evaluated minimum inhibitory concentration (MIC) of tested antimicrobials, with the MIC50 and MIC90 (the MIC where 50% and 90% of isolates were inhibited by the tested antibiotics, respectively) mostly beneath the respective breakpoint. On average, about one-fourth (24%, n = 5,718) of tested isolates was resistant to erythromycin. However, the prevalence of resistant isolates dropped from 53% (n = 1,018) in 2012 to 8% (n = 113) in 2022. The second highest prevalence of in vitro resistance was to penicillin (17%, of all isolates tested for β-lactamase production, n = 28,069). Less than 14% of isolates were resistant to the remaining assessed antimicrobial agents (cefoperazone, pirlimycin, kanamycin-cefalexin, marbofloxacin, amoxicillin-clavulanate, cefquinome, or cefazolin, respectively). Over the years, 4% (n = 959) of the S. aureus isolates selected for microbroth susceptibility testing (and 0.8% (n = 1,392) of all submitted S. aureus isolates) were methicillin-resistant S. aureus, and 5% (n = 1,162) of S. aureus isolates were multidrug resistant. However, there was an overall trend toward fewer resistant isolates. These findings are consistent with those of several European monitoring programs that reported a slight decrease of antimicrobial resistance (AMR) of bovine S. aureus in countries where antibiotic use in veterinary medicine was reduced. Notably, isolates of clinical mastitis cases were consistently less likely to express in vitro resistance than isolates obtained from milk of healthy cows or subclinical mastitis cases. In conclusion, AMR of S. aureus was decreasing and penicillin should remain the first-choice antimicrobial in the attempt of treating S. aureus intramammary infections in Bavaria.

Prevalence of extended spectrum β-lactam, methicillin, and vancomycin resistant zoonotic bacterial pathogens in milk

In this study, 194 samples of the dairy supply chain from various regions were collected, and the most prevalent pathogen discovered was Enterococcus spp., which was present at a rate of 25.77% (50/194), followed by S. aureus and E. coli, which were present at rates of 15.97% (31/194) and 14.94% (29/194), respectively. The double disc approach was used in this investigation to phenotypically confirm that five different E. coli isolates were Extended spectrum β-lactamases (ESBL) producers. By phenotyping by disc diffusion testing, it was determined that five isolates of S. aureus with coagulase positive were methicillin resistant (MRSA), while one sample of Enterococcus was found to be vancomycin resistant. This was confirmed using the BD Phoenix Diagnostic System. Further, three salmonella isolates found through conventional based techniques were confirmed as Citrobacter freuendii (n = 2), Serratia marcescens (n = 1), and Mannhemia histolytica (n = 1) using the Phoenix approach.

Molecular study on virulence and resistance genes of ST131 clone (uropathogenic/enteropathogenic Escherichia coli) hybrids in children.

Aim: To analyze ST131 clones and other characteristics in uropathogenic and atypical enteropathogenic Escherichia coli hybrids. Methods: Samples were collected from children with urinary tract infections and underwent testing for antimicrobial susceptibility, multidrug resistance and extended-spectrum β-lactamases, in vitro biofilm formation and virulence, resistance genes, hybrid pathotypes and ST131 clones. Results: E. coli isolates showed high levels of antibiotic resistance, extended-spectrum β-lactamase production, virulence genes, multidrug resistance and biofilm formation. Four (5.0%) isolates were identified as uropathogenic/atypical enteropathogenic E. coli hybrids, all of which belonged to the high-risk ST131 clone. Conclusion: Our results provide promising insights about hybrid isolates and should be addressed to improve prevention measures for hybrid pathotypes.

The directed evolution of NDM-1.

β-Lactam antibiotics are among the most frequently prescribed therapeutic agents. A common mechanism of resistance toward β-lactam antibiotics is the production of β-lactamases. These enzymes are capable of hydrolyzing the β-lactam bond, rendering the drug inactive. Among the four described classes, the metallo- β-lactamases (MBLs, class B) employ one or two zinc ions in the active site for catalysis. One of the three most clinically relevant MBLs is New Delhi Metallo- β-Lactamase (NDM-1). The current study sought to investigate the in vitro protein evolution of NDM-1 β-lactamase using error-prone polymerase chain reaction. Evaluation revealed that variants were not found to confer higher levels of resistance toward meropenem based on amino acid substitutions. Thus, we postulate that increases in transcription or changes in zinc transport may be clinically more relevant to meropenem resistance than amino acid substitutions.

Microbiological Profiles and Inflammatory Biomarkers of Bacteremia in Children in a Teaching Hospital in Kuwait: An 8-Year Retrospective Study

Objectives: The objectives of this study were to determine the bacterial profiles and prevalence of antibiotic resistance patterns of bacteria causing bacteremia in febrile children and to compare levels of inflammatory markers between children with and without bacteremia in Kuwait from 2015 to 2022. Materials and Methods: Isolates from all episodes of significant bacteremia (n = 96) during the study period were recorded and evaluated. Microorganisms were identified using standard microbiological methods. Antimicrobial susceptibility testing was carried out using the VITEK2 system and Etest method. Extended-spectrum β-lactamase (ESBL) production by Enterobacterales was detected by the double-disk diffusion method and VITEK2 system. Patient age, gender, and inflammatory markers were collected at admission and compared between patients with and without bacteremia. Results: A majority of the patients were infants (37, 40%) and newborns (13, 14%). The main ports of entry were the lower respiratory tract, the genitourinary tract, and the gastrointestinal tract. Streptococcus pneumoniae was the most common pathogen (16, 16.7%) followed by Escherichia coli (12, 12.5%), Staphylococcus aureus (10, 10.4%), and Streptococcus agalactiae (9, 9.4%). High rates of resistance to ampicillin, cefuroxime, ciprofloxacin, and trimethoprim-sulfamethoxazole were observed among the Enterobacterales. The prevalence of ESBL-producing E. coli and K. pneumoniae were 45% and 29%, respectively. The prevalence of methicillin-resistant S. aureus was 30%. Patients with bacteremia had significantly higher white blood cell (WBC) counts, absolute neutrophil count (ANC), C-reactive protein (CRP), and neutrophil-lymphocyte ratio (NLR). Conclusion: Continuous surveillance of the prevalence and antimicrobial susceptibility patterns of blood isolates is imperative for the formulation of antibiotic policy. WBC, ANC, CRP, and NLR could be valuable indicators of bacteremia in febrile children.

Incidence and risk factors of neonatal bacterial infections: a community-based cohort from Madagascar (2018–2021)

BackgroundFew studies on neonatal severe bacterial infection are available in LMICs. Data are needed in these countries to prioritize interventions and decrease neonatal infections which are a primary cause of neonatal mortality. The BIRDY project (Bacterial Infections and Antimicrobial Drug Resistant among Young Children) was initially conducted in Madagascar, Senegal and Cambodia (BIRDY 1, 2012–2018), and continued in Madagascar only (BIRDY 2, 2018–2021). We present here the BIRDY 2 project whose objectives were (1) to estimate the incidence of neonatal severe bacterial infections and compare these findings with those obtained in BIRDY 1, (2) to identify determinants associated with severe bacterial infection and (3) to specify the antibiotic resistance pattern of bacteria in newborns.MethodsThe BIRDY 2 study was a prospective community-based mother and child cohort, both in urban and semi-rural areas. All pregnant women in the study areas were identified and enrolled. Their newborns were actively and passively followed-up from birth to 3 months. Data on clinical symptoms developed by the children and laboratory results of all clinical samples investigated were collected. A Cox proportional hazards model was performed to identify risk factors associated with possible severe bacterial infection.FindingsA total of 53 possible severe bacterial infection and 6 confirmed severe bacterial infection episodes were identified among the 511 neonates followed-up, with more than half occurring in the first 3 days. For the first month period, the incidence of confirmed severe bacterial infection was 11.7 per 1,000 live births indicating a 1.3 -fold decrease compared to BIRDY 1 in Madagascar (p = 0.50) and the incidence of possible severe bacterial infection was 76.3, indicating a 2.6-fold decrease compared to BIRDY 1 in Madagascar (p < 0.001). The 6 severe bacterial infection confirmed by blood culture included 5 Enterobacterales and one Enterococcus faecium. The 5 Enterobacterales were extended-spectrum β-lactamases (ESBL) producers and were resistant to quinolones and gentamicin. Enterococcus faecium was sensitive to vancomycin but resistant to amoxicillin and to gentamicin. These pathogns were classified as multidrug-resistant bacteria and were resistant to antibiotics recommended in WHO guidelines for neonatal sepsis. However, they remained susceptible to carbapenem. Fetid amniotic fluid, need for resuscitation at birth and low birth weight were associated with early onset possible severe bacterial infection.ConclusionOur results suggest that the incidence of severe bacterial infection is still high in the community of Madagascar, even if it seems lower when compared to BIRDY 1 estimates, and that existing neonatal sepsis treatment guidelines may no longer be appropriate in Madagascar. These results motivate to further strengthen actions for the prevention, early diagnosis and case management during the first 3 days of life.

Antimicrobial resistance and biofilm formation of Escherichia coli in a Vietnamese Pangasius fish processing facility

This study aimed to investigate the occurrence, antibiotic resistance, and biofilm formation of Escherichia coli in the Vietnamese Pangasius fish processing facility. Among 144 samples including Pangasius fish, wash water, food contact surfaces, and personnel gloves, 18 E. coli isolates was detected and characterized. The E. coli was detected most frequently in wash water samples (22%, 8/36), followed by Pangasius fish (18%, 8/45). According to the antibiotic susceptibility test by the disc diffusion method, isolates showed the highest resistance against sulfamethoxazole/trimethoprim (45%), followed by tetracycline (39%), whereas all the E. coli isolates were susceptible to meropenem and fosfomycin. Notably, 39% of the isolates (7/18) were found to be multidrug resistant while no E. coli isolates were confirmed as extended-spectrum β-lactamase producers by the double-disk synergy test. The potency to form biofilm on the polystyrene surface of E. coli isolates indicated that 44% of the isolates (8/18) were classified as weak, 39% (7/18) as moderate, and 17% (3/18) as strong biofilm formers. Interestingly, multidrug resistant E. coli isolates were observed in moderate and strong biofilm producers. Additionally, either slightly acidic hypochlorous water with 40 mg/L of available chlorine or sodium hypochlorite with 100 mg/L of available chlorine exhibited a significant reduction in biofilm mass and biofilm cells of E. coli isolates. This study may provide helpful information about the actual state of E. coli isolates for effective control in the fish processing plant.

Phenotypic detection of extended spectrum beta-lactamase production in clinical and non - clinical isolates of klebsiella species of animal origins in Abeokuta, Nigeria.

Production of extended-spectrum β-lactamases (ESBLs) confer resistance to β-lactam antibiotics. This study investigated the presence of ESBL-producing Klebsiella spp in clinical and non-clinical samples from different animal species in Abeokuta, Nigeria. The species of Klebsiella were determined by biochemical characterization (Oxoid Microbact GNB 24E®), while phenotypic ESBL-production was confirmed by using the cefpodoxime and cefpodoxime/clavulanic acid combination disc kit. Ninety-five Klebsiella isolates were investigated in this study. Fifty-five (57.9%) of the isolates were obtained from the faeces of apparently healthy animals while 40 (42.1%) were from clinical samples. The Klebsiella isolates were identified as follows: K. oxytoca (34.7%), K. pneumoniae (26.3%), K. ozaenae (18.9%), K. terrigena (13.7%), K. rhinooscleromatis (5.3%), K. planticola (1.1%). Eight (8.4%) out of the 95 isolates of Klebsiella spp were identified as ESBL-producers. These included four isolates of Klebsiella pneumoniae, three of Klebsiella oxytoca and one of Klebsiella ozaenae. Five out of the eight ESBL-producing isolates were from clinical samples while three isolates were from the faeces of apparently healthy animals. The ESBL-producing isolates were 100% resistant to ampicillin, cefotaxime, ceftazidime, cefpodoxime, streptpmycin, tetracycline, compound sulfonamide, trimethoprim/sulphomethoxazole, and nalidixic acid. Apparently healthy carriers and sick animals can serve as sources of transmission of ESBL-producing Klebsiella spp to other animals and humans.

Analyses of Extended-Spectrum-β-Lactamase, Metallo-β-Lactamase, and AmpC-β-Lactamase Producing Enterobacteriaceae from the Dairy Value Chain in India.

The consumption of milk contaminated with antibiotic-resistant bacteria poses a significant health threat to humans. This study aimed to investigate the prevalence of Enterobacteriaceae producing β-lactamases (ESBL, MBL, and AmpC) in cow and buffalo milk samples from two Indian states, Haryana and Assam. A total of 401 milk samples were collected from dairy farmers and vendors in the specified districts. Microbiological assays, antibiotic susceptibility testing, and PCR-based genotyping were employed to analyze 421 Gram-negative bacterial isolates. The overall prevalence of β-lactamase genes was 10% (confidence interval (CI) (7-13)), with higher rates in Haryana (13%, CI (9-19)) compared to Assam (7%, CI (4-11)). The identified β-lactamase genes in isolates were blaCMY, blaMOX, blaFOX, blaEBC, and blaDHA, associated with AmpC production. Additionally, blaCTX-M1, blaSHV, and blaTEM were detected as ESBL producers, while blaVIM, blaIMP, blaSPM, blaSIM, and blaGIM were identified as MBL producers. Notably, Shigella spp. were the dominant β-lactamase producers among identified Enterobacteriaceae. This study highlights the presence of various prevalent β-lactamase genes in milk isolates, indicating the potential risk of antimicrobial-resistant bacteria in dairy products. The presence of β-lactam resistance raises concern as this could restrict antibiotic options for treatment. The discordance between genotypic and phenotypic methods emphasizes the necessity for comprehensive approaches that integrate both techniques to accurately assess antibiotic resistance. Urgent collaborative action incorporating rational and regulated use of antibiotics across the dairy value chain is required to address the global challenge of β-lactam resistance.

Antibiotic Resistance Profiles and Molecular Characteristics of blaCMY-2-Carrying Salmonella enterica Serovar Albany Isolated from Chickens During 2013-2020 in South Korea.

The production of β-lactamase by nontyphoidal Salmonella has become a public health issue throughout the world. In this study, we aimed to investigate the antimicrobial resistance profiles and molecular characteristics of β-lactamase-producing Salmonella enterica serovar Albany isolates. A total of 434 Salmonella Albany were obtained from feces and carcasses of healthy and diseased food-producing animals [cattle (n = 2), pigs (n = 3), chickens (n = 391), and ducks (n = 38)] during 2013-2020. Among the 434 Salmonella Albany isolates, 3.7% showed resistance to cefoxitin, and all the cefoxitin-resistant isolates were obtained from chickens. Moreover, Salmonella Albany isolates demonstrated high resistance to nalidixic acid (99.3%), trimethoprim/sulfamethoxazole (97.9%), ampicillin (86.6%), chloramphenicol (86.6%), and tetracycline (85.7%), as well as higher rates of multidrug resistance were detected in cefoxitin-resistant isolates compared to cefoxitin-susceptible isolates. All cefoxitin-resistant isolates harbored CMY-2-type β-lactamase and belonged to seven different pulsotypes, with type IV-b (43.75%) and IV-a (25%) making up the majority. In addition, genes encoding cefoxitin resistant of all blaCMY-2-harboring Salmonella Albany isolates were horizontally transmitted to a recipient Escherichia coli J53 by conjugation. Furthermore, 93.75% (15/16) of conjugative plasmids harboring blaCMY-2 genes belong to ST12/CC12-IncI1. Genetic characteristics of transmitted blaCMY-2 genes were associated with ISEcp1, which can play an essential role in the effective mobilization and expression of these genes. Salmonella Albany containing blaCMY-2 in chickens can potentially be transferred to humans. Therefore, it is necessary to restrict antibiotic use and conduct continuous monitoring and analysis of resistant bacteria in the poultry industry.

Antibiotic resistance and β-lactamase production and biofilm formation by MRSA Isolated from Dakahlia Governorate, Egypt

Antibiotic resistance and β-lactamase production and biofilm formation by MRSA Isolated from Dakahlia Governorate, Egypt