Β-lactamase Production Research Articles

Investigation of plasmid-mediated quinolone resistance among extended-spectrum β-lactamase isolates of E. coli and K. pneumoniae.

Escherichia coli and Klebsiella pneumoniae are important members of the Enterobacteriaceae family, involved in many infections. The increased resistance rate towards β-lactams and fluoroquinolones -which are the main therapeutic options- limits their treatment options. This study aimed to assess the local resistance patterns against different antimicrobials and to determine the extended-spectrum β-lactamase (ESBLs) producers. The study revealed that 36% of clinical isolates were ESBL producers, showing high resistance rates towards β-lactams and non-β-lactams, especially sulphamethoxazole-trimethoprim and fluoroquinolones. However, they were susceptible to chloramphenicol and doxycycline (33% and 20%; respectively). Also, the investigation aimed to screen the plasmid profile of quinolone-resistant ESBLs-producers and to detect the plasmid-mediated quinolone resistance genes including qnrA, qnrS, qnrB, qnrC, qnrD, and qnrVC. Moreover, the conjugative plasmid among the quinolone-resistant isolates was elucidated. The results showed that extracted plasmids of sizes ranging from ≈0.9 to 21.23 Kb, divided into 7 plasmid patterns were detected. A plasmid of approximately 21.23 Kb was found in all isolates and the QnrS gene was the most predominant gene. Moreover, the frequency of transconjugation within the same genus was higher than that recorded between different genera; where 68% of E. coli isolates transferred the resistance genes compared to Klebsiella isolates (36.6%). Plasmid profiles of transconjugants demonstrated great similarity, where 21.23 Kb plasmid was detected in all transconjugants. Since these transconjugants were quinolone-resistant ESBL producers, it has been suggested that quinolone resistance determinants might be carried on that plasmid.

Monitoring Multi-Drug Resistant Klebsiella pneumoniae in Kitagata Hot Spring, Southwestern Uganda: A Public Health Implication.

The concerning frequency of K. pneumoniae in various recreational settings, is noteworthy, especially regarding multi-drug resistant (MDR) strains. This superbug is linked to the rapid spread of plasmids carrying these resistance genes. The objective of this study was to evaluate the spatiotemporal prevalence of MDR-K. pneumoniae in the Kitagata hot spring, Southwestern Uganda. A laboratory-based descriptive longitudinal study was conducted between May and July 2023. During rainy and dry seasons, we collected eighty water samples in the morning and evening from the hot spring. The temperature at each point was measured prior to sample collection, and two samples were obtained at varying depths. 5 mL of each homogenized sample were pre-enriched in brain heart infusion broth, and subsequently in both blood and violet red bile agar. The Kirby-Bauer disk diffusion method was performed, followed by the detection of carbapenemase (CR) and extended-spectrum β-lactamase (ESBL) production. Polymerase chain reaction showed resistance genes viz. bla TEM, bla CTX-M and bla KPC. Data were analyzed using SPSS-20 to obtain chi-square tests and regression analysis. K. pneumoniae accounted for 30.0% of isolates obtained from Kitagata hot springs, with all isolates classified as multi-drug resistant. All isolates were resistant to ampicillin, rifampicin, ceftazidime, and azithromycin (79.2%). Additionally, 95.8% of isolates harbored bla TEM gene alone and both bla TEM and bla CTX genes, followed by bla KPC alone (33.3%), with 25% harboring all three resistance genes. During the dry season, K. pneumoniae had a higher prevalence (35.0%) compared to the wet season (25.0%). The prevalence of MDR-K. pneumoniae significantly increased over the course of the study. The presence of the three studied resistance genes in the isolates showed a positive correlation with the second phase of sample collection and the dry season but exhibited a negative correlation with temperature, except for isolates harboring either bla TEM alone or bla TEM+KPC+CTX genes. Kitagata hot spring serves as a hotspot for continuous dissemination and acquisition of MDR-K. pneumoniae harboring resistance genes that encode for ESBL and CR production. The healthcare sector ought to implement an ongoing monitoring and surveillance system as well as robust antimicrobial resistance stewardship programs aimed at delivering health education to the community.

Burden of Multidrug-Resistant Gram-Negative Bacterial Infections in a Tertiary Care Hospital

Multidrug-resistant (MDR) Gram-negative bacterial infections have emerged as a major public health concern. The aim of the present study was to detect the rate of infections due to MDR Gram-negative bacteria (GNB) in a tertiary care hospital, the rate of Carbapenemases and AmpC-β-lactamases production and the Antimicrobial susceptibility test pattern (AST) among MDR GNB. The rate of MDR GNB during the study period was 25.70%. Urine samples showed the highest contribution to the total MDR GNB. Among the total MDR GNB isolates, 166 were randomly selected and included in the present study. A higher rate of MDR GNB was reported among male patients (61.5%) compared to the females (38.5%) and most of them were from the patients aged between 61-70 years (30.7%). The most prevalent MDR GNB was Klebsiella pneumoniae 80 (48.12%), followed by Escherichia coli 43 (25.9%). AST of MDR GNB revealed their significant resistance to β-lactamases/β-lactamases inhibitors, cephalosporins, fluoroquinolones and carbapenem drugs (98%). Of 123 MDR Enterobacterales, 83% of them were found to be Metallo β-lactamase (MBLs) producers by mCIM and eCIM methods. Of 43 MDR non-fermenters, 29 (67.4%) of them were found to be carbapenemase producers by MHT. About 29.51% of MDR GNB isolates were found to be AmpC producers by AmpC disk test. A reliable and rapid phenotypic method to detect carbapenemases and AmpC β-lactamases among MDR GNB in a routine microbiology laboratory method is clinically important to guide antibiotic therapy and implementation of effective infection control practices.

Prevalence of Extended-Spectrum ß-Lactamases (ESBLs) and AmpC ß-Lactamases in Clinical Isolates of Multiple Drug-Resistant Escherichia coli

The current study aims to investigate the prevalence of extended-spectrum ß-lactamases (ESBLs) and AmpC β-lactamases in multiple-drug-resistant Escherichia coli (e.g., multidrug-resistant (MDR), extensively drug-resistant (XDR), and pan-drug-resistant (PDR)) collected from hospitalized patients in Baghdad. The results showed that the prevalence of ESBLs among E.coli isolates was high. From the total 113 E.coli isolates, 75 (66.37%) were ESBL-producing, while 38 (33.63%) were non-ESBL-producing. Out of 75 ESBL-positive isolates, 39 (52%) were obtained from females and 36 (48%) from males. Additionally, 43 (57.33%) isolates were collected from urine samples, and the highest production of ESBLs was obtained from the age group 41–60 years (29.33%). Moreover, out of 111 MDR E.coli, 64 (57.66%) exhibited a positive ESBL test, while 47 (42.34%) did not. Out of 24 XDR E.coli isolates, 11 (45.83%) demonstrated positive ESBLs, while 13 (54.17%) showed negative ESBLs. The antimicrobial susceptibility test results showed that positive ESBL E.coli isolates were more drug-resistant than negative ESBL isolates. The positive ESBLs of E.coli exhibited a higher resistance rate to the β-lactam antibiotics and showed a co-resistance to non-β-lactam antibiotics. Phenotypic detection of AmpC β-lactamase by the screening of cefoxitin-resistant isolates revealed that 43 (38.05%) isolates were considered positive for AmpC β-lactamase production. However, the PCR technique gives different results. In conclusion, the prevalence of ESBL and AmpC β-lactamase producing E. coli is rapidly increasing among clinical isolates of MDR, XDR, and possibly PDR E.coli.

Phenotypic and Genotypic Characterization of AmpC Beta-Lactamase in Clinical Isolates of Pseudomonas aeruginosa Findings From a Tertiary Care Hospital.

Background and aim Pseudomonas aeruginosa is an opportunistic pathogen responsible for various healthcare-related infections, which are difficult to treat due to intrinsic and acquired resistance. This study aimed to investigate AmpC β-lactamase production using phenotypic and genotypic methods in Pseudomonas aeruginosa strains isolated from a tertiary care hospital in Karad, Maharashtra, India. Material and methods Over one year, a descriptive cross-sectional study was conducted at the Department of Microbiology, Krishna Institute Medical Sciences, Krishna Vishwa Vidyapeeth, Karad. Phenotypic detection of AmpC beta-lactamase was performed using the Cefoxitin-Cloxacillin Double-Disc Synergy Test method, and genotypic detection was conducted using conventional polymerase chain reaction (PCR) targeting the bla Pseudomonas-derived cephalosporinases (PDC) and bla cephamycinase (CMY) genes. Results Out of 205 clinical isolates of Pseudomonas aeruginosa, 110 (53.66%) showed AmpC production phenotypically, while 86 (41.95%) were positive genotypically. The blaPDC gene was detected in 36.10% of isolates, and the blaCMY gene in 10.73% ofisolates. Conclusions The study findings indicate that AmpC-β-lactamase stands out as the primary resistance mechanism in strains of Pseudomonas aeruginosaisolated from the hospital. PCR study concluded that blaPDC (36.10 %) was the leading gene responsible for AmpC synthesis among study isolates. Early detection of AmpC beta-lactamase production by employing phenotypic and genotypic methods is crucial for detecting antibiotic resistance. This dual approach enables healthcare professionals to decide on the most effective antibiotics and mitigate the development of resistance.

Culture-based bacterial evaluation of the appendix lumen and antibiotic susceptibility of acute appendicitis in Japan: A single-center retrospective analysis.

The question of whether to perform an appendectomy or conservative treatment for acute appendicitis can differ depending on the facility or surgeon, but antibiotic treatment is administered regardless of whether an appendectomy or conservative treatment is selected. We investigated the contemporary bacteriology for acute appendicitis and evaluated the antibiotic sensitivity of the bacteria that are currently associated with appendicitis. We retrospectively analyzed the bacterial culture results and antibiotic susceptibility of 141 patients who underwent appendicitis surgery, including the identification and antimicrobial susceptibility of the cultured bacteria within the excised appendices. Bacterial cultures were positive in 131 cases (92.9%). The most commonly isolated bacteria were Escherichia coli (90 isolates, 66.7%), followed by Enterococcus species (n = 19, 14.5%), Pseudomonas aeruginosa (n = 18, 13.7%), Streptococcus species (n = 15, 11.5%), and Klebsiella species (n = 8, 6.1%). Eight strains (8.8%) of E coli were extended-spectrum β-lactamase producers, and ten strains (11.1%) were fluoroquinolone-resistant. Tazobactam/piperacillin and meropenem inhibited the growth of 100% of the major identified bacteria. The patients with appendicoliths had a significantly higher bacterial culture rate. Enterococcus species were frequently isolated from the patients with complicated appendicitis. For the antibiotic treatment of appendicitis, it is essential to understand the patient's microbiological profile and antibiotic susceptibilities. Research from Asian countries such as Japan can enhance our knowledge of regional antibiotic resistance patterns and inform effective treatment strategies.

Impact of the COVID-19 pandemic on extended-spectrum β-lactamase producing Escherichia coli in urinary tract and blood stream infections: results from a nationwide surveillance network, Finland, 2018 to 2022

BackgroundBefore the COVID-19 pandemic there has been a constant increase in antimicrobial resistance (AMR) of Escherichia coli, the most common cause of urinary tract infections and bloodstream infections. The aim of this study was to investigate the impact of the COVID-19 pandemic on extended-spectrum β-lactamase (ESBL) production in urine and blood E. coli isolates in Finland to improve our understanding on the source attribution of this major multidrug-resistant pathogen.MethodsSusceptibility test results of 564,233 urine (88.3% from females) and 23,860 blood E. coli isolates (58.8% from females) were obtained from the nationwide surveillance database of Finnish clinical microbiology laboratories. Susceptibility testing was performed according to EUCAST guidelines. We compared ESBL-producing E. coli proportions and incidence before (2018–2019), during (2020–2021), and after (2022) the pandemic and stratified these by age groups and sex.ResultsThe annual number of urine E. coli isolates tested for antimicrobial susceptibility decreased 23.3% during 2018–2022 whereas the number of blood E. coli isolates increased 1.1%. The annual proportion of ESBL-producing E. coli in urine E. coli isolates decreased 28.7% among males, from 6.9% (average during 2018–2019) to 4.9% in 2022, and 28.7% among females, from 3.0 to 2.1%. In blood E. coli isolates, the proportion decreased 32.9% among males, from 9.3 to 6.2%, and 26.6% among females, from 6.2 to 4.6%. A significant decreasing trend was also observed in most age groups, but risk remained highest among persons aged ≥ 60 years.ConclusionsThe reduction in the proportions of ESBL-producing E. coli was comprehensive, covering both specimen types, both sexes, and all age groups, showing that the continuously increasing trends could be reversed. Decrease in international travel and antimicrobial use were likely behind this reduction, suggesting that informing travellers about the risk of multidrug-resistant bacteria, hygiene measures, and appropriate antimicrobial use is crucial in prevention. Evaluation of infection control measures in healthcare settings could be beneficial, especially in long-term care.

Preliminary snapshot reveals a relationship between multidrug-resistance and biofilm production among enterobacteriaceae isolated from fecal samples of farm-raised poultry in ceará, Brazil

Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for β-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of β-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC β-lactamase and extended-spectrum β-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer.

Colistin-, cefepime-, and levofloxacin-resistant Salmonella enterica serovars isolated from Egyptian chicken carcasses

ObjectivesThe emergence of multidrug-resistant (MDR) Salmonella strains, especially resistant ones toward critically important antimicrobial classes such as fluoroquinolones and third- and fourth-generation cephalosporins, is a growing public health concern. The current study, therefore, aimed to determine the prevalence, and existence of virulence genes (invA, stn, and spvC genes), antimicrobial resistance profiles, and the presence of β-lactamase resistance genes (blaOXA, blaCTX-M1, blaSHV, and blaTEM) in Salmonella strains isolated from native chicken carcasses in Egypt marketed in Mansoura, Egypt, as well as spotlight the risk of isolated MDR, colistin-, cefepime-, and levofloxacin-resistant Salmonella enterica serovars to public health.MethodsOne hundred fifty freshly dressed native chicken carcasses were collected from different poultry shops in Mansoura City, Egypt between July 2022 and November 2022. Salmonella isolation was performed using standard bacteriological techniques, including pre-enrichment in buffered peptone water (BPW), selective enrichment in Rappaport Vassiliadis broth (RVS), and cultivating on the surface of xylose-lysine-desoxycholate (XLD) agar. All suspected Salmonella colonies were subjected to biochemical tests, serological identification using slide agglutination test, and Polymerase Chain Reaction (PCR) targeting the invasion A gene (invA; Salmonella marker gene). Afterward, all molecularly verified isolates were screened for the presence of virulence genes (stn and spvC). The antimicrobial susceptibility testing for isolated Salmonella strains towards the 16 antimicrobial agents tested was analyzed by Kirby–Bauer disc diffusion method, except for colistin, in which the minimum inhibition concentration (MIC) was determined by broth microdilution technique. Furthermore, 82 cefotaxime-resistant Salmonella isolates were tested using multiplex PCR targeting the β-lactamase resistance genes, including blaOXA, blaCTX-M1, blaSHV, and blaTEM genes.ResultsSalmonella enterica species were molecularly confirmed via the invA Salmonella marker gene in 18% (27/150) of the freshly dressed native chicken carcasses. Twelve Salmonella serotypes were identified among 129 confirmed Salmonella isolates with the most predominant serotypes were S. Kentucky, S. Enteritidis, S. Typhimurium, and S. Molade with an incidence of 19.4% (25/129), 17.1% (22/129), 17.1% (22/129), and 10.9% (14/129), respectively. All the identified Salmonella isolates (n = 129) were positive for both invA and stn genes, while only 31.8% (41/129) of isolates were positive for the spvC gene. One hundred twenty-one (93.8%) of the 129 Salmonella-verified isolates were resistant to at least three antibiotics. Interestingly, 3.9%, 14.7%, and 75.2% of isolates were categorized into pan-drug-resistant, extensively drug-resistant, and multidrug-resistant, respectively. The average MAR index for the 129 isolates tested was 0.505. Exactly, 82.2%, 82.2%, 63.6%, 51.9%, 50.4%, 48.8%, 11.6%, and 10.1% of isolated Salmonella strains were resistant to cefepime, colistin, cefotaxime, ceftazidime/clavulanic acid, levofloxacin, ciprofloxacin, azithromycin, and meropenem, respectively. Thirty-one out (37.8%) of the 82 cefotaxime-resistant Salmonella isolates were β-lactamase producers with the blaTEM as the most predominant β-lactamase resistance gene, followed by blaCTX-M1 and blaOXA genes, which were detected in 21, 16, and 14 isolates respectively).ConclusionThe high prevalence of MDR-, colistin-, cefepime-, and levofloxacin-resistant Salmonella serovars among Salmonella isolates from native chicken is alarming as these antimicrobials are critically important in treating severe salmonellosis cases and boost the urgent need for controlling antibiotic usage in veterinary and human medicine to protect public health.Graphical

Antimicrobial Resistance in Uropathogenic Escherichia coli Strains Isolated from Relapses from Recurrent Urinary Tract Infections.

Little is known about the characteristics of uropathogenic Escherichia coli (UPEC) associated with recurrent urinary tract infections (RUTIs). The present study aimed to analyze the phenotypic antimicrobial resistance of recurrent UPEC isolates attributable to either relapse or reinfection. A total of 140 E. coli strains were isolated from 70 outpatients with RUTIs. All isolates were analyzed by random amplified polymorphic DNA-polymerase chain reaction to evaluate genetic similarity between the first and second isolates. We found that 64.2% (45/70) of outpatients had a relapse with the primary infecting E. coli strain and 35.7% (25/70) had reinfection with a new E. coli strain. Compared with reinfecting strains, relapse UPEC isolates exhibited much higher antimicrobial resistance; 89% of these isolates were multidrug-resistant and 46.6% were extended-spectrum β-lactamase producers. Our study provides evidence that RUTIs are mainly driven by the persistence of the original strain in the host (relapses) despite appropriate antibiotic treatments, and only RUTIs attributed to relapses seem to favor multidrug resistance in UPEC isolates.

Characterization of Vibrio parahaemolyticus isolated from clinical specimens and oysters in Thailand.

Vibrio parahaemolyticus is a common pathogen that can cause seafood-borne gastroenteritis in humans. We determined the prevalence and characteristics of V. parahaemolyticus isolated from clinical specimens and oysters in Thailand. Isolates of V. parahaemolyticus from clinical specimens (n = 77) and oysters (n = 224) were identified by biochemical testing, polymerase chain reaction (PCR) assays, and serotyping. The toxin genes, antimicrobial resistance, and β-lactamase production were determined. A total of 301 isolates were confirmed as V. parahaemolyticus by PCR using specific primers for the toxR gene. The majority of clinical isolates carried the tdh+/trh- genotype (82.1%), and one of each isolate was tdh-/trh+ and tdh+/trh+ genotypes. One isolate from oyster contained the tdh gene and another had the trh gene. Twenty-six serotypes were characterized among these isolates, and O3:K6 was the most common (37.7%), followed by OUT:KUT, and O4:K9. In 2010, most clinical and oyster isolates were susceptible to antibiotics, with the exception of ampicillin. In 2012, clinical isolates were not susceptible to cephalothin (52.4%), streptomycin (95.2%), amikacin (66.6%), kanamycin (61.9%), and erythromycin (95.2%), significantly more frequently than in 2010. More than 95% of isolates that were not susceptible to ampicillin produced β-lactamase enzymes. We found toxin genes in two oyster isolates, and the clinical isolates that were initially determined to be resistant to several antibiotics. Toxin genes and antimicrobial susceptibility profiles of V. parahaemolyticus from seafood and environment should be continually monitored to determine the spread of toxin and antimicrobial resistance genes.

Microbiological profile and antimicrobial susceptibility of bacteria associated with urinary tract infections in Ukrainian adults

The aim of the study was to analyse the microbial profile of the urinary tract infections (UTIs) due to urolithiases and to study susceptibility to antibiotics in its causative agents. The main method of the research was bacteriological. Antimicrobial susceptibility testing was conducted by serial microdilution assay in accordance with recommendations of the European committee on antimicrobial susceptibility testing (EUCAST). For present study 128 unique urine samples were collected from patients with UTIs associated with urolithiasis. Among all collected specimens, 78% (n=100) gave clinically signi­ficant growth. Among all examined participants, 88.9% of women (64/72) and 64.3% of men (36/56) had confirmed UTI; in the study, female/male ratio was 1.4 (χ2=9.76; p<0.05). Microorganisms identified in our study predominantly belon­ged to Bacteria (93.4%), and yeasts of Candida genus comprised only 6.6%. Among all, 66.1% were representatives of Enterobacterales (n=80), particularly, Escherichia coli (38.0%), Klebsiella oxytoca (15.7%), Klebsiella pneumoniae (2.5%), Enterobacter cloacae (5.8%), Proteus mirabilis (4.1%). Isolates of Pseudomonas aeruginosa comprised 3.3%. Among gram-positive isolates, Staphylococcus spp. (14.1%) and Enterococcus spp. (9.9%) were identified. Regarding female/male distribution, the biggest proportion of gram-positive bacteria were isolated from women, statistically significant results were obtained for sex distribution of S. saprophyticus (p<0.05). Antimicrobial susceptibility of Enterobacterales was variable, and the best results were obtained for carbapenems, novel antibiotics (cefiderocol, ceftolozane-tazobactam and ceftazidime-avibactam), aminoglycosides and tigecycline. There were 9 isolates with pro­duction of carbapenemases and resistant to all relevant β-lactam antibiotics. All isolated Staphylococcus spp. were β-lactamase producers, one isolate of S. saprophyticus demonstrated methicillin-resistance. To summarise, there is an ongoing outbreak of multidrug-resistant infections in Ukraine and causative agents of UTIs are among the most important contributors. Availability of data on the local antimicrobial susceptibility profile may guide the informed decision making in etiotropic treatment, therefore, contribute to global efforts in rational drug use and fight the resistance escalation.

Genomic insights into resistome, virulome, and mobilome as organic contaminants of ESKAPE pathogens and E. coli recovered from milk, farm workers, and environmental settings in Hainan, China

The ESKAPE pathogens and E. coli are of significant public health concern and are listed among the top priorities of the World Health Organization. These pathogens are equally important for animal and public health, but their interaction with animal, human, and environmental aspects needs to be sufficiently studied. We investigated the comprehensive molecular characterization of three ESKAPE pathogens and E. coli recovered from milk, farm workers, and environmental settings in Hainan province. Minimum inhibitory concentration (MIC), extended-spectrum β-lactamase production, and biofilm production were performed per set standard protocols. The isolates were further processed by PCR and sequencing to detect resistome, virulome, and mobilome. The study found four Enterobacteriaceae species (E. coli, n=32; K. pneumoniae, n=13; E. cloacae, n=3; E. aerogenes, n=1) among n=49 bacterial isolates from the study area. Most of the strains exhibited resistance against tetracycline (71.4%), ampicillin (61.2%), florfenicol (44.9%), and ciprofloxacin (42.9%), while none of the strains was resistant against meropenem and amikacin. The MDR and ESBL-production percentages were 55.1% and 34.7 %, respectively. The resistance determinants for β-lactams (blaTEM, blaOXA-2, blaSHV, blaCTX-M), aminoglycosides (aac(3ʹ)-IIa), quinolones (qnrB, qnrS), tetracyclines (tetA, tetD), florfenicol (floR), sulfonamides (sul1, sul2), trimethoprim (dfrA14), and MDR efflux pumps (oqxA, oqxB) were detected along with diverse plasmid replicon types and integrons (intl3, 55.1%; intl1, 18.4%). The detection of virulence determinants was noted at a higher rate, and most of the strains were identified as biofilm producers by genotype (85.7%). The current study findings revealed diversified resistance and virulence determinants along with mobilome in ESKAPE pathogens and E. coli, which may pose a significant threat to human health through the food chain and environmental exposure and need immediate attention.

Molecular Characterization and Antibacterial Resistance Determination of Escherichia coli Isolated from Fresh Raw Mussels and Ready-to-Eat Stuffed Mussels: A Major Public Health Concern.

Our study focused exclusively on analyzing Escherichia coli (E. coli) contamination in fresh raw mussels and ready-to-eat (RTE) stuffed mussels obtained from authorized and regulated facilities. However, it is critical to recognize that such contamination represents a significant public health threat in regions where unauthorized harvesting and sales practices are prevalent. This study aimed to comprehensively assess the prevalence, molecular characteristics, and antibacterial resistance profiles of E. coli in fresh raw mussels and RTE stuffed mussels. E. coli counts in fresh raw mussel samples ranged from 1 to 2.89 log CFU/g before cooking, with a significant reduction observed post-cooking. RTE stuffed mussel samples predominantly exhibited negligible E. coli presence (<1 log CFU/g). A phylogenetic analysis revealed a dominance of phylogroup A, with variations in the distribution observed across different sampling months. Antibacterial resistance was prevalent among the E. coli isolates, notably showing resistance to ampicillin, streptomycin, and cefotaxime. Extended-spectrum β-lactamase (ESβL) production was rare, with only one positive isolate detected. A variety of antibacterial resistance genes, including tetB and sul1, were identified among the isolates. Notably, virulence factor genes associated with pathogenicity were absent. In light of these findings, it is imperative to maintain rigorous compliance with quality and safety standards at all stages of the mussel production process, encompassing harvesting, processing, cooking, and consumption. Continuous monitoring, implementation of rigorous hygiene protocols, and responsible antibacterial drug use are crucial measures in mitigating food safety risks and combating antibacterial resistance. Stakeholders, including seafood industry players, regulatory agencies, and healthcare professionals, are essential to ensure effective risk mitigation and safeguard public health in the context of seafood consumption.

Antibiotyping, RAPD- and ERIC-PCR fingerprinting of Klebsiella pneumoniae clinical isolates at a tertiary reference hospital in Denpasar, Bali, Indonesia.

Klebsiella pneumoniae is a healthcare-associated infections agent and could be an extended spectrum β-lactamase (ESBL) producer. Understanding the transmission of this bacterium in a hospital setting needs accurate typing methods. An antibiogram is used to detect the resistance pattern of the isolates. Random Amplified Polymorphic DNA (RAPD) and Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR are rapid, technically simple, and easy-to-interpret DNA typing methods. This study aimed to evaluate the use of antibiotyping, RAPD-, and ERIC-PCR to investigate the heterogeneity of K. pneumoniae isolated from clinical specimens. The antibiograms of 46 K. pneumoniae clinical isolates were determined by Vitek® 2 Compact. All isolates underwent RAPD-PCR using AP4 primer and ERIC-PCR using ERIC-2 primer. The dendrogram was generated using the GelJ software and analyzed to determine its similarity. The analysis of antibiogram and the molecular typing diversity index was calculated using the formula of the Simpson's diversity index. About 71.7% of the isolates were ESBL-producers, and more than 80% of isolates were susceptible to amikacin, ertapenem, and meropenem. The antibiotyping produced 32 diverse types with DI = 0.964. In addition, the RAPD-PCR produced 47 different types with DI = 1, while ERIC-PCR was 46 (DI=0.999). Antibiotyping, RAPD- and ERIC-PCR showed powerful discrimination power among the isolates, supported the diversity of K. pneumoniae isolates in current study. These combination could be promising tools for clonal relationship determination, including in tracking the transmission of the outbreak's agent in hospital setting.

Surgical Site Infections in Gastrointestinal Surgeries: Estimation of Prevalence, Risk Factors and Bacteriological Profile.

Surgical site infections (SSIs) are one of the leading causes of operation-related adverse effects.To create an effective hospital infection program, information about a local pattern is essential. The ever-changing pattern of infections and inappropriate use of antibiotics has predisposed to the development of drug-resistant strains and has made the management of SSIs arduous. The purpose of this study is to estimate prevalence and identify risk factors and commonest organisms associated with SSIs. In this analytical cross-sectional study, the relationship between various risk factors and the development of SSIswas evaluated in patients undergoing elective surgery and staying at least seven days postoperatively in the Department of Surgical Gastroenterology and Liver transplant for a study duration of two months. Diagnosis of SSIs was based on modified CDC criteria. Wound pus was followed by blood collection in suspected secondary septicemia. MacConkey and blood agar were used to culture pus; brain heart infusion broth was used for blood samples. Antimicrobial susceptibility testing was carried out using Mueller-Hinton agar by the Kirby-Bauermethod. Twelve out of 50 had developed postsurgical wound infections where Gram-negative organisms prevailed over Gram-positive ones. The associated risk factors identified in this study are age, BMI, wound class, American Society of Anesthesiologists (ASA) score, preprocedural WBC count >10,000, and the duration of surgery. Escherichia coli is the causative microbe for the majority of infections (35.7%). Gram-negative bacteria isolated in this study were extended-spectrum β-lactamase (ESBL) producers. Multidrug-resistant organisms were predominant. Conclusion: The present study identified an SSI rate of 24% in gastrointestinal surgeries. The sensitivity and resistance pattern of the organisms isolated will help in measures to be taken to devise a proper and effective current hospital antibiotic prophylaxis policy.

Detection of Metallo β-Lactamase in Acinetobacter Species Using Phenotypic Methods with their Antibiotic Resistance Profile in Tertiary Care Hospital

Background: Acinetobacter species are commonly found in nature, in water, and in soil, and also, and they have been isolated from humans and animals. In the hospital setting, Acinetobacter species has emerged as a major opportunistic pathogen, being able to colonize and develop infections in patients. In Acinetobacter species, β-lactamases and outer membrane alterations are likely to function together to impart resistance. Understanding the epidemiology, and resistance mechanism, and for infection management and preventing a potential global health crisis, techniques for identifying Carbapenem-Resistant-Acinetobacter species are essential. Aim: To detect Metallo β-Lactamase (MBL) in Acinetobacter species with their antimicrobial susceptibility pattern. Material and Methods: 100 Acinetobacter species isolates from various clinical samples such as blood, cerebrospinal fluid, sputum, bronchoalveolar lavage, pus, urine, wound swab, and body fluids were included in the study. Phenotypic tests such as, Disc Potentiation test &amp; Modified Hodge test were used to detect the presence of Metallo β-lactamase in imipenem &amp; meropenem-resistant isolates. Results: The highest prevalence of Acinetobacter was found in blood (37%), followed by sputum (31%) and others [pus, urine, ascitic fluid, cerebrospinal fluid (CSF), bronchoalveolar Lavage (BAL), and pleural fluid]. A maximum number of Acinetobacter were isolated from MICU followed by medicine and surgery. The Modified Hodge test yielded the largest percentage of MBL-positive Acinetobacter isolates (67.26%) when compared to the Disc Potentiation test method (50.45%). Conclusion: Early detection of Metallo β-lactamase production is essential for planning appropriate treatment according to the resistance mechanisms of the multi-drug resistant strains, as well as for efficient infection control procedures to prevent the spread of infection.

Assessment of Airborne Extended Spectrum β-Lactamase Producing Enterobacteriaceae Isolates from Motor Parks in Benin City, Nigeria

Aim: The study was aimed at assessing airborne bacteria and extended spectrum β-lactamase producing Enterobacteriaceae isolated from the motor parks in Benin City. Methodology: Airborne bacteria samples were collected in the motor parks (Central, Ugbowo, Agip, 19th Street, and Ekosodin Park), in Benin City using the settled plate method on Nutrient and MacConkey agar. Temperature, relative humidity, and airborne bacteria of the different parks were determined. The bacterial isolates were identified using phenotypic method. The antibiotic susceptibility profile was investigated by the disc diffusion method. The Enterobacteriaceae isolates were screened for Extended-spectrum β-lactamase (ESBL) production potentials. Virulence factor analysis and detection of ESBL genes (TEM, CTX-M, SHV, and OXA) were carried out on the selected ESBL producers. Results: The relative humidity recorded at the parks at the point of agar plate exposure ranged from 82 ̶ 90%. The airborne heterotrophic bacterial and coliform counts from the motor parks ranged from 9.50±0.63 × 102 ̶ 1.18±0.02 ×103 cfu/m3 and 2,48±0.41×102 ̶ 3.30±0.41×102 cfu/m3 respectively. The identified Enterobacteriaceae were Citrobacter freundii, Serratia marcescens, Citrobacter koseri, Klebsiella pneumoniae, Morganella morganii, Klebsiella oxytoca, Shigella dysenteriae, Proteus mirabilis, Escherichia coli, Enterobacter cloacae and Citrobacter diversus. The isolate with highest frequency of occurrence was E. coli with values of 30.48 %. The isolate K. pneumoniae had the highest MAR index of 0.8. The isolate S. marcescens had the highest virulent factor of 60% and possessed all the ESBL genes detected. Conclusion: Strong infection control measures should be put in place because more ESBL-producing Enterobacteriaceae have emerged in the surroundings of specific parks in Benin City.

Association Between Biofilm Formation and Extended-Spectrum Beta-Lactamase Production in Klebsiella pneumoniae Isolated from Fresh Fruits and Vegetables.

The presence of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in fresh fruits and vegetables is a growing public health concern. The primary objective of this study was to investigate the relationship between biofilm formation and extended-spectrum β-lactamase (ESBL) production in K. pneumoniae strains obtained from fresh fruits and vegetables. Out of 120 samples analysed, 94 samples (78%) were found to be positive for K. pneumoniae. Among the K. pneumoniae strains isolated, 74.5% were from vegetables, whereas the remaining (25.5%) were from fresh fruits. K. pneumoniae isolates were resistant to at least three different classes of antibiotics, with ceftazidime (90%) and cefotaxime (70%) showing the highest resistance rates. While the high occurrence of ESBL-producing and biofilm-forming K. pneumoniae strains were detected in vegetables (73.5% and 73.7%, respectively), considerable amounts of the same were also found in fresh fruits (26.5% and 26.3%, respectively). The results further showed a statistically significant (P < 0.001) association between biofilm formation and ESBL production in K. pneumoniae strains isolated from fresh fruits and vegetables. Furthermore, the majority (81%) of the ESBL-producing strains harbored the blaCTX-M gene, while a smaller proportion of strains carried the blaTEM gene (30%), blaSHV gene (11%) or blaOXA (8%). This study highlights the potential public health threat posed by K. pneumoniae in fresh fruits and vegetables and emphasizes the need for strict surveillance and control measures.

Influence of β-lactam pharmacodynamics on the systems microbiology of gram-positive and gram-negative polymicrobial communities.

We sought to evaluate the pharmacodynamics of β-lactam antibacterials against polymicrobial communities of clinically relevant gram-positive and gram-negative pathogens. Two Enterococcus faecalis isolates, two Staphylococcus aureus isolates, and three Escherichia coli isolates with varying β-lactamase production were evaluated in static time-killing experiments. Each gram-positive isolate was exposed to a concentration array of ampicillin (E. faecalis) or cefazolin (S. aureus) alone and during co-culture with an E. coli isolate that was β-lactamase-deficient, produced TEM-1, or produced KPC-3/TEM-1B. The results of the time-killing experiments were summarized using an integrated pharmacokinetic/pharmacodynamics analysis as well as mathematical modelling to fully characterize the antibacterial pharmacodynamics. In the integrated analysis, the maximum killing of ampicillin (Emax) against both E. faecalis isolates was ≥ 4.11 during monoculture experiments or co-culture with β-lactamase-deficient E. coli, whereas the Emax was reduced to ≤ 1.54 during co-culture with β-lactamase-producing E. coli. In comparison to monoculture experiments, culturing S. aureus with KPC-producing E. coli resulted in reductions of the cefazolin Emax from 3.25 and 3.71 down to 2.02 and 2.98, respectively. Two mathematical models were created to describe the interactions between E. coli and either E. faecalis or S. aureus. When in co-culture with E. coli, S. aureus experienced a reduction in its cefazolin Kmax by 24.8% (23.1%RSE). Similarly, β-lactamase-producing E. coli preferentially protected the ampicillin-resistant E. faecalis subpopulation, reducing Kmax,r by 90.1% (14%RSE). β-lactamase-producing E. coli were capable of protecting S. aureus and E. faecalis from exposure to β-lactam antibacterials.