Kirby-Bauer Disc Diffusion Method Research Articles

Profiling of antimicrobial resistance (AMR) and multi drug resistance (MDR) of <em>Escherichia coli</em> isolates from livestock, wild animals and an ornamental fish farm in Polgahawela, Sri Lanka

The pattern of antimicrobial resistance (AMR) and the prevalence of multi drug resistance (MDR) of Escherichia coli (E. coli) isolates from livestock, wild animals and an ornamental fish farm were investigated in a selected area in Polgahawela, Sri Lanka. Sampling area of one square Km containing an ornamental fish farm, a broiler farm, cattle, goat, and backyard poultry which are located separately within the sampling area but not in an integrated farming system with its associated wildlife was mapped using GPS. Faecal samples were examined from 89 wild animals (terrestrial and avian species), 28 livestock animals (including poultry) as well as 40 samples from an ornamental fish farm (fish faecal material, pond water and pond sediment). E. coli was isolated using standard methods and AMR profiles were investigated for 12 antimicrobials using Kirby-Bauer disc diffusion method. Sixty nine percent (62/89) of wild animals and 86% (24/28) of livestock samples were positive for E. coli whereas the isolation rate was 17.5% (7/40) in the samples from the ornamental fish farm. A maximum of two randomly selected E. coli isolates from each sample, making a total of 164 isolates were tested for AMR of which 114, 43 and 7 were from wild animals, livestock and the ornamental fish farm, respectively. The E. coli isolates tested against 12 antimicrobials reflected that the proportions of E. coli isolates resistant to at least one antimicrobial were 30%, 63% and 71% in wild animals, livestock and the ornamental fish farm, respectively. Multidrug-resistant E. coli isolates were detected in wild animals, livestock and the samples from ornamental fish farm. Overall, according to the statistical analysis, E. coli isolated from livestock and the ornamental fish farm reflected a significantly higher chance of carrying AMR compared with E. coli from wild animals.

Antimicrobial sensitivity pattern of aerobic bacteria isolated from hunting dogs in Maiduguri, Nigeria

Hunting dogs may be a potential source of transmission of pathogenic, zoonotic, or drug-resistant bacteria to people since they may carry the pathogenic bacteria in their oral cavities. As a result of clinic-based cross-sectional study conducted to evaluate the level of multidrug resistant bacteria, colonization of the bacteria in the oral cavities of hunting dogs that appeared apparently healthy were found in Maiduguri. Oral swab samples were taken from one hundred and ninety-three (193) apparently healthy hunting dogs. Using colony morphology and oxidase, catalase, starch hydrolysis, casein hydrolysis, indole, methyl-red and Voges-Proskauer test (MR-VP) the bacteria were isolated and identified. The isolates were tested for antibiotic susceptibility to ten (10) different antibiotics using the Kirby-Bauer disk diffusion method in accordance with standard procedure. Escherichia coli (E. coli) accounted for the greater proportion of 100 (51.8%) of the isolates. Others were Staphylococcus spp. 19 (18.8%), Klebsiella spp. 13 (6.7%), and Streptococcus spp. 7 (3.6%). Escherichia coli isolates were highly resistant to Penicillin 100 (100%), Ceftriaxone (100%) and Tetracycline (80%) while Klebsiella spp. was found resistant to Amikacin (100%), Gentamicin (100%) and Ceftriaxone (100 %). Similarly, Staphylococcus spp. obtained in the current study was found to be resistant to Ciprofloxacin (100%), Gentamicin (100%) and Amikacin (100%) while Streptococcus isolates were resistant to Tetracycline (100%), Penicillin (100%) and Chloramphenicol (100%). Susceptibility of the isolates were E. coli 100 (100%) for Chloramphenicol. Owners of dogs should refrain from using antibiotics indiscriminately. In conclusion, the study revealed the presence of dissimilar bacteria in the oral cavities of hunting dogs using cultural isolation, biochemical and antibiotics sensitivity tests in the study area.

Comparative Antimicrobial Activity of Lactobacillus acidophilus and Lactobacillus rhamnosus on Clinically Isolated Escherichia coli: An In vitro Study

Aim: The aim of present study is to evaluate the comparative antimicrobial activity of Lactobacillus acidophilus and Lactobacillus rhamnosus on clinical isolates of Escherichia coli.
 Study Design: Cross-sectional observational study.
 Place and Duration of Study: This study was conducted in Department of Medical Microbiology, School of Medical Education between January 2023 to September 2023.
 Methodology: A total of 100 E. coli isolates collected from various diagnostic laboratories were included in the sample population and the prevalence of XDR, MDR, and non MDR isolates among them were determined by Kirby-Bauer disk diffusion method. The inhibitory activity of untreated and treated (pH adjusted) suspension of standard strains of L. acidophilus and L. rhamnosus on E. coli were determined by agar overlay method and the data was statistically analysed using ANOVA single-factor.
 Results: The antimicrobial activity was confirmed for untreated and treated suspension of Lactobacillus spp. by measuring the zone of inhibition surrounding E. coli strains spotted on MRS medium but treated suspension exerted greater inhibitory activity than untreated suspensions of both Lactobacillus spp. and among the treated suspension L. rhamnosus exhibit greater inhibitory activity. Statistical analysis of this data using ANOVA single-factor was found to be not significant (P >0.05), that is treated suspension of both L. acidophilus and L. rhamnosus has the independent activity against E. coli. While untreated suspensions of both L. acidophilus and L. rhamnosus was significant (P =0.03), that is untreated suspension of L. rhamnosus (mean inhibition of 12.19 mm) has greater inhibitory activity than untreated cell cultures of L. acidophilus (mean inhibition of 11.39 mm).
 Conclusion: This result, disclosed that even if both Lactobacillus spp. exhibit antimicrobial activity against E. coli, L. rhamnosus showed greater inhibition than L. acidophilus. The study suggested the use probiotic Lactobacillus as a biotherapeutic in antibiotic resistant E. coli infection and should be further studied for their human health benefits.

Recovery of Methicillin Resistant Staphylococci from Public Vehicles in Kathmandu

Objectives: The purpose of this study was to determine the extent of staphylococcal contamination in public vehicles in Kathmandu and to determine the antibiotic susceptibility pattern of the isolates. Methods: This cross-sectional study was conducted from December 2022 to May 2023 in the Microbiological laboratory of Padma Kanya Multiple Campus, Kathmandu. A total of 120 swab (sterile cotton swab moistened with sterile normal saline) samples were collected by gently rubbing the surfaces from 19 different micro-buses during the time of heavy passenger flow (office time) and transported to the laboratory maintaining a cold chain. Staphylococcus aureus and Coagulase negative Staphylococci (CoNS) were identified by their characteristic yellow pigmented colonies on Mannitol Salt Agar (MSA) and the ability of S. aureus to produce coagulase enzyme. Kirby-Bauer disc diffusion method was employed to test the antibiotic susceptibility pattern of isolates. MRSA were identified on the basis of the zone of inhibition (<21 mm diameter) against Cefoxitin 30mcg disc. Results: Out of 41 Staphylococcal isolates, 46.36% were S. aureus, among which 84.21% exhibited methicillin resistance (MRSA). All Coagulase Negative Staphylococci (CoNS) isolates (n=22) were resistant to methicillin (MRCoNS). MRSA and MRCoNS isolates were also resistant to antibiotics like Penicillin and Erythromycin. Conclusion: This study reports relatively high occurrence of MRSA in environmental samples, predominantly in areas frequently touched by people indicating the possibility of easy spread of these organisms and subsequent opportunistic infections.

Assessment of antibiotic resistant profile of coliform and Staphylococcus spp. isolated from milk from Kathmandu valley

Antimicrobial resistance (AMR) among milk pathogens is increasing, which is a serious threat to consumers’ health. Therefore, this study aims to assess the current antibiotic profile of coliforms and Staphylococcus spp. in milk samples. For this, thirty milk samples were collected from various locations in Kathmandu district. Isolation and enumeration were done on selective media using streak-plate and pour-plate techniques, respectively. Antibiotic susceptibility testing (AST) was done by the Kirby-Bauer disk diffusion method. A total of 48 bacteria were isolated, of which 31 were coliform and 17 Staphylococcus spp. Among the coliforms, Klebsiella spp. (n=17, 54.84%) was the most predominant in both raw (n=12, 70.6%) and pasteurized milk (n=5, 29.4%), followed by E. coli and Citrobacter spp. While for Staphylococcus spp., 15 (88.24%) were S. aureus and 2 (11.76%) were coagulase negative Staphylococcus (CONS). S. aureus was dominant in raw milk (n=13) rather than pasteurized milk (n=2). The AST of coliforms showed higher resistance towards ampicillin (96.75%), followed by cefoxitin, ciprofloxacin, nalidixic acid, nitrofurantoin, piperacillin, co-trimoxazole, ceftriaxone, chloramphenicol, and amikacin in descending order. In the case of S. aureus, higher resistance was observed for penicillin G (100.00%), followed by cefoxitin, ampicillin, ceftriaxone, tetracycline, ciprofloxacin, and amikacin. Further, 12 (70.53%) S. aureus were confirmed as methicillin-resistant S. aureus (MRSA). And a total of 10 (32.25%) coliforms and 9 (52.95%) S. aureus were identified as multiple drug resistant (MDR) strains. Thus, it can be concluded that antibiotic resistance among milk isolates of the coliform and Staphylococcus spp. is highly prevalent, and these can be a potential source of incurable milk-borne infections. Thus, routine assessment of microbial quality as well as AMR surveillance should be done on milk isolates to ensure the safety of consumer’s health.

Antibiotic Resistance in Escherichia Coli Bacteria Isolated from Water Sources and Waste Disposal in Livestock Farms in East Lombok

Poor antimicrobial stewardship in livestock farms will lead to the emergence of bacterial resistance to antibiotics. Dug wells as a water source and waste disposal on livestock farms have a close distance, allowing transmission of Escherichia coli-resistant bacteria through soil absorption and fecal contamination. This study aims to isolate Escherichia coli from water sources and livestock waste disposal in East Lombok Regency and determine their sensitivity to several antibiotics. The type of this research is a descriptive cross-sectional survey using four water wells and four waste disposals with a criterion of < 10m range. Escherichia coli bacteria were isolated using culture techniques on Eosin Methylene Blue Agar, and identification was carried out using gram staining and biochemical tests. Determining sensitivity to antibiotics was performed using the Kirby-Bauer disk-diffusion method. The results showed that Escherichia coli bacteria have been isolated from water sources and waste disposal on livestock farms in East Lombok Regency. 100 % Escherichia coli isolates sensitive to Gentamicin, Ciprofloxacin, and Cefotaxime. 87.5% Escherichia coli isolates sensitive to Oxytetracycline, 12.5% ​​Escherichia coli isolates resistant to Oxytetracycline, 100% Escherichia coli isolates resistant to Penicillin G. Escherichia coli bacteria isolated from water sources and waste disposal at a livestock farm in East Lombok.

Bacterial Uropathogens causing Urinary Tract Infection at Hetauda Hospital

Introduction: Urinary tract infection is the infection of the uroepithelium that mainly affects kidney, ureter, urinary bladder and urethra. The causative agents of urinary tract infections are bacteria and fungi. Among these, bacteria are the most causative uropathogens of urinary tract infections. Objectives: The objective of this study is to isolate, identify, characterized and perform antibiotic sensitivity test from the bacterial isolates. Methods: A descriptive cross-sectional study was conducted from March 2023 to May 2023. Ethical approval was obtained from Institutional Review Committee (IRC), Madan Bhandari Academy of Health Sciences, IRC-32-079. Total of 1120 urine samples were collected during this study. Convenient sampling technique was used for this study. Clean catch or mid-stream urine was collected in a sterile container. All urine samples were submitted to Department of Microbiology for culture. A set of biochemical tests were done for bacterial identification. Antibiotic sensitivity test was performed by Kirby-Bauer disk diffusion method. Results: Total of 1120 urine samples were collected from patients suspected to Urinary Tract Infections. Total urine culture positive was 340 (30.36%). Of these bacterial isolates, Escherichia coli (248, 73%) was the most common species, followed by Klebsiella species (26, 7.6%), Staphylococcus saprophyticus (23, 6.76%) and Enterococcus fecalis (18, 5.3%). Conclusion: As prevalence of bacteria causing urinary tract infections is increasing day by day; so its proper isolation, identification, characterization with their antibiotic profile is necessary as it forms the base line for the clinicians to choose appropriate antimicrobial agents for empirical as well as rational treatment for UTIs.

Characterization and multilocus sequence typing of Clostridium perfringens isolated from patients with diarrhoea and food poisoning in Tai'an region, China

ObjectivesClostridium perfringens (C. perfringens) is a significant opportunistic pathogen. This study aims to examine the occurrence of C. perfringens in patients with diarrhoea and food poisoning and compare the genetic similarities with strains found in poultry retail markets and poultry farms in the same city (Tai'an, China). MethodsClostridium perfringens was isolated from 30 human faecal samples and genotyped using multiplex PCR. The antimicrobial susceptibility test was conducted using the Kirby-Bauer disk diffusion method. Genetic relationships were analysed through Multi-locus sequence typing (MLST) and Phylogenetic analysis. ResultsThe positive rate of C. perfringens was found to be 96.67%. Among the positive samples, 91.67% of the faecal samples from patients with food poisoning contained type F strains of C. perfringens, while only 16.67% of the samples from diarrhoea cases contained type F. The drug susceptibility test revealed that the majority of isolates displayed broad-spectrum antimicrobial resistance. Out of the 57 isolates tested for drug susceptibility, 89.47% demonstrated resistance to at least three antibiotics. The MLST results indicated that strains originating from the same host and environment tended to be more closely related. However, certain strains associated with food poisoning and diarrhoea in patients shared the same ST and CC as some strains found in the retail market. These strains were also found to be phylogenetically similar to some retail market strains, suggesting potential risks to human health. ConclusionsTherefore, it is crucial to enhance the management of poultry retail markets in order to mitigate these associated risks.

Antibiotic susceptibility patterns of pathogens isolated from hospitalized patients with advanced HIV disease (AHD) in Bihar, India.

To describe the prevalence of common bacterial pathogens and antibiotic susceptibility patterns amongst advanced HIV disease (AHD) patients admitted between May 2019 and March 2021 to a Médecins Sans Frontières (MSF)-supported AHD inpatient unit in Bihar, India. A retrospective analysis of routinely collected demographic, clinical and microbiological data. Antibacterial susceptibility testing was done by an accredited referral laboratory using the modified Kirby-Bauer disc diffusion method. A total of 238 isolates from 577 patients were identified through culture testing. Patient median (IQR) age was 38 (31-45) years, and 75% were male. Predominant sample types included blood (600; 38%), urine (266; 17%) and sputum (178; 11%). Of the isolated bacteria, Escherichia coli (80; 13.9%) was the most prevalent, followed by Klebsiella pneumonia (54; 9.4%), Pseudomonas aeruginosa (22; 3.8%), Klebsiella oxytoca (10; 1.7%), Proteus mirabilis (9; 1.6%), and Acinetobacter baumannii (7; 1.2%). The resistance pattern showed that most bacterial isolates were highly resistant to commonly prescribed antibiotics such as third-generation cephalosporins, fluoroquinolones and co-trimoxazole. Most pathogens were moderately resistant to antibiotics from the WHO Watch group, such as meropenem and piperacillin/tazobactam. In contrast, isolates were more susceptible to aminoglycosides, such as amikacin, gentamicin and nitrofurantoin. In Bihar, inpatients with AHD displayed a concerning array of antibiotic-resistant infections. This study provides a starting point from which further work on antimicrobial resistance in this vulnerable cohort of patients can be conducted.

Bacterial resistance of the most locally isolated pathogens to commonly used antibiotics in Kerbala/Iraq

Antibiotics are one of the biggest threats to human health. Antibiotics remain the most critical resource in the worldwide management of infections. Identifying the causative agent in an infectious disease is vital to determine their antimicrobial susceptibility. The susceptibility of pathogenic microbes has a critical role in deciding the morbidity and mortality rates of these diseases—the aim of the current study is to investigate the antimicrobial susceptibility of common pathogens in Karbala. The specimens were collected from 370 patients diagnosed with bacterial infections from Al-Hindiya Hospital in 2022. Standard microbiological techniques were implemented. Identification of microorganisms was made using biochemical tests. A pure culture was prepared for antimicrobial susceptibility testing. Antibiotic sensitivity testing was performed using the Kirby-Bauer disk diffusion method, and the results were interpreted. Using the standard operating procedure and the standard bacteriological procedures, we found that the most common pathological microorganisms predominance was Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus spp. And Shigella spp. The antimicrobial patterns were: Escherichia coli strains were found to be highly sensitive to meropenem (84%) with excellent sensitivity to Levofloxacin (68%) and Nitrofurantoin (64 %) while it highly resistant to Amoxicillin, Erythromycin, Vancomycin, Novobiocin, Trimethoprim-sulfamethoxazole, Cefotaxime, Cefepime and Tetracycline and moderate to Ciprofloxacin, Azithromycin, and Gentamicin. The most common causative agent of urinary tract infections (which are the most common infections in the population studied) was Escherichia coli. Meropenem was a broad-spectrum antimicrobial that many bacterial spp were susceptible to.

THE ETHANOL EXTRACT OF JUKUT PENDUL (KYLLINGA NEMORALIS) EXHIBITS INHIBITORY ACTIVITY AGAINST THE GROWTH OF STAPHYLOCOCCUS AUREUS

Staphylococcus aureus is a pathogenic bacteria that is often found to have resistance to antibiotics. Jukut pendul (Kyllinga nemoralis) extract is known to have antibacterial compounds such as flavonoids, tannins, saponins, and steroids. The purpose of this study was to determine the inhibitory ability of jukut pendul ethanol extract against Staphylococcus aureus bacteria. This research used the Kirby-Bauer disc diffusion method with five treatments within five repetitions. Data analysis was carried out using One Way Anova variance analysis. The variation in extract concentration tested was 5, 10, 20, and 40% with 96% ethanol as the control group and Ciprofloxacin as the work control. The results showed that extract concentrations of 5, 10, 20, and 40% were able to inhibit Staphylococcus aureus bacteria with an average inhibitory zone of 9,36; 10,85; 11,64; and 12.15 mm, respectively. The inhibitory zone formed indicates that jukut pendul ethanol extract has moderate to strong inhibitory ability in inhibiting the growth of Staphylococcus aureus bacteria.

Isolation, identification, and characterization of resistant bacteria to antibiotics from pharmaceutical effluent and study of their antibiotic resistance.

Pharmaceutical effluents primarily enter aquatic environments through the discharge of treated and untreated wastewater from various sources, including hospitals, pharmaceutical manufacturing facilities, and households. Microbes sourced from pharmaceutical effluents such as Pseudomonas spp. pose a significant public health concern because of their high levels of resistance to multiple drugs and extreme multidrug resistance. Therefore, the present study was conducted for the isolation, identification, and molecular characterization of selected isolates from pharmaceutical effluents and also determined their antibiotic sensitivity patterns. From June 2016 to March 2017, a study was conducted on four well-known pharmaceutical companies specializing in antibiotic production in Dhaka and Gazipur. Four wastewater samples were collected from various origins and then brought to the Bacteriology laboratory for microbiological examination. Twelve pure isolates were obtained and characterized through cultural and biochemical tests while molecular identification of Pseudomonas spp. was performed using the 16S rRNA gene sequence. Twelve commercially available antibiotics were used for antibiotic sensitivity tests using Kirby-Bauer disk diffusion methods. We isolated the most predominant isolates, Pseudomonas aeruginosa (41.67%), followed by Bacillus spp. (33.33%) and Staphylococcus spp. (25%) respectively. Among 12 antibiotics, ciprofloxacin is 100% sensitive against P. aeruginosa, while the remaining 11 antibiotics are 100% resistant. Bacillus spp. showed 100% resistance to all antibiotics while 50% sensitive to vancomycin and 100% to chloramphenicol, respectively. Staphylococcus spp. was 100% resistant to all antibiotics. Our research suggested that P. aeruginosa is the reservoir of antibiotic resistance genes and spreads disease to humans from the environment. The findings of this study, i.e., the isolation, identification, and characterization of antibiotic-resistant bacteria from pharmaceutical effluent have highlighted, comprehended, and mitigated the dissemination of antibiotic resistance and opportunistic bacteria.

Secondary Metabolites Production of Bacillus spp. Isolated from Sea Cucumbers (Holothuria scabra) and their Activity against Mycobacterium smegmatis

New anti-tuberculosis agents are very important due to Multidrug-Resistant and Extensively Drug-Resistant Tuberculosis problems. Mycobacterium smegmatis can be used to replace Mycobacterium tuberculosis as bacteria test to increase the velocity of anti-tuberculosis screening. To answer the need for new drugs, exploration of secondary metabolites from Bacillus spp. can be conducted. Bacillus spp. are known to produce antimicrobials, including discovery of iturins, fengycins, and pumilacidins. This study explored the Bacillus spp. isolated from fermented intestines of Holothuria scabra. The production of Bacillus sp. Holothuria scabra Fermented Intestine (HSFI) secondary metabolites was done using culture media containing starch as a carbon source, as well as yeast and peptone as a nitrogen source. Production capacity of secondary metabolites of Bacillus sp. HSFI was calculated, to determine its potential as an antibacterial producer. Inhibition testing of secondary metabolites of Bacillus sp. HSFI against M. smegmatis was performed using the Kirby-Bauer disk diffusion method. Based on the results of the inhibition test, it was concluded that Bacillus sp. HSFI-9 has the greatest potential to inhibit the growth of M. smegmatis, with a moderate inhibition (7.67 mm). Production of secondary metabolites from Bacillus sp. HSFI-9 is exceptionally good with an extract production capacity of 24.6 mg/L.

Isolation and Identification of Antibiotic-Susceptible Bacteria from Abattoir Effluent in Port Harcourt, Rivers State, Nigeria

Abattoir environment can become a significant reservoir for antibiotic resistance bacteria, particularly in abattoirs that do not treat their waste before discharge. This study seeks to verify the antibiotics susceptibility profile of bacteria isolated from abattoir wastewater in Port Harcourt, River State, Nigeria. The bacteria were isolated from the wastewater using a standard plating technique. The antibiotics sensitivity pattern of all bacterial isolates was determined by the Kirby-Bauer disk diffusion method. Isolates with high multiple antibiotic resistance (MAR) index (≥0.5) were screened for genes for pathogenicity (icaC, adhesion gene) and antibiotic resistance (QnrA gene). The abattoir wastewaters were contaminated by bacteria resistant to no less than two of the antibiotics experimented with (MAR index range, 0.2-1.0). The isolates were identified as Acinetobacter brisouii, Bacillus altitudinis, Bacillus stratosphericus and Priestia flexa. Among these isolates, 2(50.0%) harboured the QnrA gene while 3(75.0%) harboured the icaC gene. The findings underscore the importance of abattoir wastewater as an environmental flashpoint for antibiotic resistance. Detection of bacteria with multiple antibiotic resistance in abattoir wastewater would inform cautious use of antibiotics, to check the spread of antibiotic resistance emanating from this source.

Detection of ESBLs in Pseudomonas aeruginosa Isolated from Different Body Fluids

Background: The present study was carried out in order to detect the production of ESBLS in Pseudomonas aeruginosa and their susceptibility pattern against different antibiotics.
 Materials and Methods: A total of 100 isolates of P. aeruginosa was analyzed for the production of ESBLs by using phenotypic confirmatory test and the results were determined. The antibiotic susceptibility against various antibiotics was performed by the Kirby-Bauer Disc diffusion method on Mueller-Hinton Agar.
 Results: Out of the 100 isolates tested 20 isolates were positive for the production of ESBLs, with a high prevalence of 36.3% found in the pus samples followed by the sputum (26%), blood (22.2%) and urine (5.4%), respectively. Imipenem was found to be the most effective antibiotic with 100 per cent susceptibility followed by Ofloxacin. A drug resistance of 57% for ceftazidime was noted against P. aeruginosa followed by cefotaxime. A high prevalence rate of P. aeruginosa was detected in males.
 Conclusion: This study showed the rising tendency of multidrug-resistant strains of the Enterobacteriaceae family, especially P. aeruginosa in the hospital settings, which is a great concern for clinicians and patients to treat these resistant strains.

Characterization of VIM, VEB and CTX-M Beta-lactamase Gene in Escherichia coli and Pseudomonas aeruginosa Isolated from Urine Samples of Patients Visiting a Tertiary Hospital in Abakaliki

The spread and convergence of multiple beta-lactamase genes across distinct resistant bacterial populations from various hosts and settings demonstrates increased risk of morbidity and mortality in humans. This study was undertaken to characterize blaVIM, blaVEB and blaCTX-M beta-lactamase gene in Escherichia coli and P. aeruginosa isolates from patients visiting a tertiary hospital in Abakaliki. A total of three hundred (300) urine samples were collected from patients and were subjected to bacteriological examination using culture, Gram staining and biochemical technique, for routine microbiological identification and further confirmed using the VITEK-2 Automated System (Biomerieux, France). Antimicrobial susceptibility studies were determined using the Kirby–Bauer disk diffusion method. All isolate were further screen for various beta-lactamase resistant gene by PCR using specific primer. Of the 300 urine samples collected, prevalence rate of 187 (62.3%) and 91 (30.3 %) E. coli and P. aeruginosa were recorded. The isolates exhibited 50.0-100% percentage of resistance to Amoxycillin-Clavulanic acid, Azetronam, Cefoxitin, Ceftriaxone and Piperacillin/tazobactam. The proportion of beta-lactamase gene in E. coli were as follows (VEB 143/76.5 %; CTX-M 175/93.5 %; VIM 77/41.2 %) while beta-lactamase gene in P. aeruginosa were as follows (VEB 91/100 %; CTX-M 63/69.2%; VIM 48/52.7 %). The presence of these gene in our study indicates the possibility of therapeutic failure, serious consequences for infection control and increased risk of morbidity and mortality in patients. Hence, continuous effort in hospital surveillance, infection control, and clinical audits must be conducted to fight against the rapid development and spread of antibiotic-resistant bacteria pathogens. Keywords: Beta-lactamase, Escherichia coli, Pseudomonas aeruginosa, VIM, VEB, CTX-M

Magnitude of extended-spectrum β-lactamase and carbapenemase producing Enterobacteriaceae among commonly vended street foods in Arba Minch town, southern Ethiopia

BackgroundThe rising prevalence of extended-spectrum beta-lactamase and carbapenemase-producing Enterobacteriaceae (ESβL-PE) in street foods poses a significant risk to human health due to its epidemiological significance. Thus, the aim of this study was to determine the magnitude of foodborne Enterobacteriaceae that produce carbapenemase and ESβL, as well as their patterns of antibiotic resistance, in the studied area.MethodsA community-based cross-sectional study was carried out from January 1st, 2023, to February 30th, 2023. One hundred randomly chosen street-vended food items (one hundred grams of each food item) were aseptically collected, and aliquots of 0.1 ml from the homogenized (25 g of samples into 225 ml of buffered peptone water (BPW)) were inoculated on MacConkey agar and Xylose Lysine Deoxycholate Agar (XLD). Enterobacteriaceae isolates were identified using various biochemical tests. ESβL and carbapenemase were first screened by indicator cephalosporins and carbapenem antibiotics, respectively. ESβL and carbapenemase were confirmed by a double-disc synergy test and modified carbapenem inactivation methods, respectively. Kirby-Bauer disc diffusion method was used for the antimicrobial-resistant test.ResultsA total of 112 Enterobacteriaceae belonging to six different genera were isolated. E. coli was attributed 39 (34.8%), followed by Citrobacter spp. 22 (19.6%) and K. pneumoniae 18 (16.1%), with only 8 (7.1%) isolated Salmonella spp. About 15.2% (n = 17) and 8.9% (n = 10) of Enterobacteriaceae were phenotypically confirmed to be extended-spectrum beta-lactamase (ESβL) and carbapenemase producers, respectively. The highest percentage of ESβL-producing isolates was attributed to K. pneumoniae (n = 5), E. coli (n = 4), and Enterobacter spp. (n = 3). Proteus spp. and Salmonella spp. isolates were carbapenemase-negative. All carbapenemase-positive isolates were found to be ESβL-producers. 70.6% (12/17) of ESβL-producing Enterobacteriaceae were found to be multidrug-resistant (MDR).ConclusionA considerable number of multidrug-resistant ESβL and carbapenemase-producing Enterobacteriaceae were identified, suggesting that street foods may be a potential source of MDR foodborne infections. Consequently, it is important to conduct routine examinations of street food items and track trends in medication resistance.

Resistance to aminoglycoside and quinolone drugs among Klebsiella pneumoniae clinical isolates from northern Jordan

This study aimed to identify phenotypic and genotypic aminoglycoside and quinolone non-susceptibility and the prevalence of aminoglycoside-modifying enzymes and plasmid-mediated quinolone resistance genes among K. pneumoniae clinical isolates from northern Jordan. K. pneumoniae isolates (n = 183) were tested for antimicrobial susceptibility using the Kirby-Bauer disk diffusion method. The double-disk synergy test was used for the detection of the extended-spectrum beta-lactamase phenotype. Polymerase chain reaction was used to detect genes encoding aminoglycoside-modifying enzyme (aac (3′)-II, aac (6′)-II, aac (6′)-Ib, ant (3″)-I, aph (3′)-VI, armA, and rmtB), and plasmid-mediated quinolone resistance (qnrA, qnrB, qnrC, qnrD, qnrS, acc(6′)-Ib–cr, qepA, and oqxAB) genes. Multi-locus sequence typing was used to elucidate the genetic diversity of selected isolates. The non-susceptibility percentages to aminoglycosides and quinolones were 65.0 % and 61.7 %, respectively. The most frequent aminoglycoside-modifying enzyme gene was ant (3″)-I at 73.8 %, followed by aac (6′)-Ib at 25.1 %, aac (3′)-II at 17.5 %, aph (3′)-VI at 12.0 %, armA at 9.8 %, and rmtB at 0.5 %. Aac (6′)-II was not detected among the isolates. The most frequent plasmid-mediated quinolone resistance gene was oqxAB at 31.7 %, followed by qnrS at 26.2 %, qnrB at 25.7 %, and aac(6′)-Ib–cr at 25.7 %. QnrA, qnrD, qebA, and qnrC were not detected among the isolates. Aac (3′)-II, aac (6′)-Ib, aph (3′)-VI, armA, qnrB, qnrS, and acc(6′)-Ib–cr were significantly associated with non-susceptibility to aminoglycosides, quinolones, and beta-lactams. Among 27 randomly selected K. pneumoniae isolates, the most common sequence type was ST2096, followed by ST348 and ST1207. Overall, 19 sequence types were observed, confirming a high level of genetic diversity among the isolates. High percentages of non-susceptibility to the studied antimicrobials were found and were associated with the presence of several resistance genes. Similar studies should be periodically carried out to monitor changes in the prevalence of resistance phenotypes and genotypes of isolates.

Enterococcus species: insights into antimicrobial resistance and whole-genome features of isolates recovered from livestock and raw meat in Ghana.

Enterococcus spp. have gradually evolved from commensals to causing life-threatening hospital-acquired infections globally due to their inherent antimicrobial resistance ability and virulence potential. Enterococcus spp. recovered from livestock and raw meat samples were characterized using antimicrobial susceptibility testing and whole-genome sequencing. Isolates were confirmed using the MALDI-ToF mass spectrometer, and antimicrobial susceptibility was determined using the Kirby-Bauer disk diffusion method. Whole genome sequencing was performed on isolates resistant to two or more antibiotics. Bioinformatics analysis was performed to determine sequence types, resistance and virulence gene content and evolutionary relationships between isolates from meat and livestock samples, and other enterococci genomes curated by PATRIC. eBURST analysis was used to assign genomes to clonal complexes. Enterococcus spp. were predominantly E. faecalis (96/236; 41%) and E. faecium (89/236; 38%). Overall, isolates showed resistance to erythromycin (78/236; 33%), tetracycline (71/236; 30%), ciprofloxacin (20/236; 8%), chloramphenicol (12/236; 5%), linezolid (7/236; 3%), ampicillin (4/236; 2%) and vancomycin (1/236, 0.4%). Resistance to two or more antimicrobial agents was detected among 17% (n = 40) Enterococcus spp. Resistance genes for streptogramins [lsa(A), lsa(E), msr(C)], aminoglycosides [aac(6')-Ii, aph(3')-III, ant(6)-Ia, aac(6')-aph(2″), str], amphenicol [cat], macrolides [erm(B), erm(T), msr(C)], tetracyclines [tet(M), tet(L), tet(S)] and lincosamides [lsa(A), lsa(E), lnu(B)] were detected among the isolates. Genes for biofilm formation, adhesins, sex pheromones, cytolysins, hyaluronidase, oxidative stress resistance, quorum-sensing and anti-phagocytic activity were also identified. Potential plasmids with replicon sequences (rep1, rep2, repUS43, repUS47, rep9a, rep9b) and other mobile genetic elements (Tn917, cn_5536_ISEnfa1, Tn6009, ISEnfa1, ISEfa10) were detected. Clinically relevant E. faecium ST32 and ST416 clones were identified in meat samples. The occurrence of antimicrobial-resistant Enterococcus spp. in livestock and raw meat samples, carrying multiple resistance and virulence genes, including known clones associated with hospital-acquired infections, underscores the critical need for employing robust tools like whole genome sequencing. Such tools provide detailed data essential for ongoing surveillance efforts aimed at addressing the challenge of antimicrobial resistance with a focus on one health.

Phenotypic Characterization and Plasmid DNA Profiling of Multidrug-Resistant Escherichia coli and Staphylococcus aureus in Wastewater Effluents From Healthcare Environments in Lafia, Nigeria

Background: Multidrug-resistant Escherichia coli and Staphylococcus aureus are frequent culprits of severe healthcare-associated infections and have been identified as significant pollutants in hospital settings. The research into plasmids as potential carriers for transferring new resistance genes among clinical pathogens has been quite constrained. This study was conducted to determine the extent of multidrug resistance and the presence of plasmids in E. coli and S. aureus isolates derived from wastewater effluents at healthcare institutions in Lafia, Nigeria. Methods: A total of 231 effluent samples were collected from different units within the healthcare facilities and bacterial identification performed using standard CLSI identification techniques. Phenotypic multidrug resistance was analyzed using the Kirby-Bauer disc diffusion method while plasmid DNA was extracted by alkaline lysis and separated using 0.8% agarose gel electrophoresis. Results: A total of 167 (72.3%) and 175 (75.6%) samples were positive for E. coli and S. aureus, respectively. Both E. coli and S. aureus exhibited the greatest resistance to amoxicillin, with resistance rates of 79.0% and 66.3%, respectively. Conversely, the lowest resistance was observed for levofloxacin (26.3%) and cotrimoxazole (25.1%) in E. coli and S. aureus, respectively. The study did not find any significant correlation between the phenotypic antibiotic resistance profiles of the isolates and different wastewater discharge points (P>0.05). Out of the total isolates, 77 (46.1%) of E. coli and 51 (29.1%) of S. aureus were resistant to all tested antibiotics. A majority of these isolates exhibited multiple antibiotic resistance index (MARI) values greater than 0.5, with 87.4% of E. coli and 80.6% of S. aureus demonstrating multidrug resistance. Plasmid analysis for E. coli indicated that the largest proportion of the selected isolates (46.7%) carried double plasmids with sizes ranging from 1500 to 6000 base pairs (bp), and 6.7% had no plasmids. In the case of S. aureus, 53.3% of the isolates harbored a single plasmid with a size of 7500 bp, while 46.7% had no plasmids. Conclusion: The wastewater discharged from healthcare facilities in the examined community was found to be significantly contaminated with multidrug-resistant organisms carrying plasmids with resistance genes.