Microbial Diversity and Antibiotic Susceptibility Pattern of Bacteria Associated with Motorcycle Helmets

Emergence of mcr-1 Gene in Colistin-Resistant Escherichia coli Isolates from Chicken in Chitwan, Nepal

The escalating prevalence of colistin-resistant Escherichia coli in poultry has emerged as a significant concern. This study aimed to assess the occurrence of the mcr-1 gene in colistin-resistant E. coli isolates from poultry samples. A cross-sectional study was conducted at National Avian Disease Investigation Laboratory, Nepal, on 210 chicken meat samples, including liver, heart, and spleen. E. coli was isolated and identified by conventional cultural methods. Antibiotic resistance pattern was assessed by the Kirby-Bauer disc diffusion method. The mcr-1 gene was detected by conventional polymerase chain reaction. The average viable count in chicken meat samples was log 6.01 CFU (colony-forming unit)/g, whereas the average coliform count was log 3.85 CFU/g. Coliforms were detected in at least one sample from 48.01% of total samples. The prevalence of E. coli in all meat samples was 39.52%. Liver accounted for the largest fraction of E. coli isolates (45.45%). Cefepime was the most effective antibiotic. Among all isolates, 45 (54.21%) were multidrug-resistant E. coli, 17 (20.48%) were colistin-resistant E. coli, and 11 (64.70%) harbored the mcr-1 gene. High prevalence of multidrug-resistant E. coli isolates, colistin-resistant isolates, and mcr-1 gene-carrying isolates indicates a serious concern, as it could potentially lead to colistin resistance in human pathogens through horizontal transfer of resistant genes from poultry to humans.

Multidrug resistance, biofilm formation and detection of bla CTX-M and bla VIM genes in E. coli and Salmonella isolates from chutney served at the street-food stalls of Bharatpur, Nepal

Antimicrobial resistance (AMR) amid the bacteria found in ready-to-eat foods is a grave concern today warranting an immediate intervention. The current study was undertaken to explore the status of AMR in E. coli and Salmonella species in ready-to-eat Chutney samples (n = 150) served at the street food stalls in Bharatpur, Nepal, with a major focus on detecting extended-spectrum β-lactamase (ESBL) and metallo β-lactamase (MBL) genes along with biofilm formation. Average viable counts, coliform counts, and Salmonella Shigella counts were 1.33 × 10⁶±141481.4, 1.83 × 10⁵±91303.6, and 1.24 × 10⁵±63933.19 respectively. Out of 150 samples, 41 (27.33%) harbored E. coli, of which 7 were E. coli O157:H7; whereas Salmonella spp. were found in 31 (20.67%) samples. Bacterial contamination of Chutney by E. coli and Salmonella and ESBL-production were both found significantly affected by different sources of water used, personal hygiene and literacy rate of the vendors as well as by the type of cleaning materials used to wash knives and chopping boards (P < 0.05). Antibiotic susceptibility testing revealed that imipenem was the most effective drug against both types of bacterial isolates. Additionally, 14 (45.16%) Salmonella isolates and 27 (65.85%) E. coli isolates were found to be multi-drug resistant (MDR). Total ESBL (bla _CTX-M) producers reported were 4 (12.90%) Salmonella spp. and 9 (21.95%) E. coli. Only 1 (3.23%) Salmonella spp. and 2 (4.88%) E. coli isolates were bla _VIM gene carriers. Dissemination of knowledge of personal hygiene amongst the street vendors and consumer awareness regarding ready-to-eat foods are crucial factors that can be suggested to curtail the emergence and transmission of food-borne pathogens.

Bacterial Assessment of Stethoscopes Used by Healthcare Workers at a Tertiary Care Government Hospital in Bharatpur, Nepal

The transmission of healthcare-associated infections (HCAIs) in healthcare settings is a serious challenge in the medical fraternity. Medical devices, such as stethoscopes used by healthcare workers (HCWs), are likely to harbor a considerable number of pathogenic microbes, which may result in the transmission of HCAIs. This study sought to investigate bacterial contamination of stethoscopes used by HCWs at Bharatpur Hospital, Nepal. During the study period of 3 months from December 2019 to February 2020, a total of 87 stethoscopes were examined; bacterial pathogens were isolated and identified by culture and biochemical tests, and their susceptibilities against different antibiotics were determined using standard protocols of the Clinical and Laboratory Standards Institute (CLSI). The disc diffusion method was used primarily to screen for extended-spectrum beta-lactamase (ESBL)- and metallo-beta-lactamase (MBL)-producing isolates, followed by their confirmation using cephalosporin/clavulanate combination discs and the disc potentiation methods, respectively. In addition, molecular detection of blaCTX-M and blaVIM genes was performed using conventional polymerase chain reaction (PCR). Of the 87 stethoscopes examined, more than a quarter (28.7%) were colonized with different pathogenic bacteria. Bacterial contamination of stethoscopes was found to be significantly associated with various factors, such as disinfecting routine, method of disinfection, and department of the hospital (p < 0.05). A higher rate of bacterial contamination was observed on the diaphragm of the stethoscope (12.64%) and among HCWs who overlooked hand hygiene practices (45.45%). The prevalence of methicillin-resistant S. aureus (MRSA) was 44.44%, and approximately half of the Gram-negative isolates (47%) were multidrug resistant (MDR). Imipenem (81.25%) and chloramphenicol (83.33%) were found to be the most effective antibiotics for Gram-negative and Gram-positive bacteria, respectively. Phenotypic screening showed that 43.75% of isolates were ESBL producers, and 18.75% were MBL producers, but blaCTX-M and blaVIM genes were detected in only 31.25% and 6.25% of isolates, respectively. The results of the study call for effective stethoscope disinfection practices along with the judicious use of antibiotics by HCWs in order to minimize cross-contamination, emergence of resistance, and spread of nosocomial infections in clinical settings.

Beta-Lactamase-Producing Gram-Negative Bacterial Isolates Among the Patients Attending a Tertiary Care Hospital, Kathmandu, Nepal

Over the times, carbapenems have been the choice of drug for treating multidrug-resistant (MDR) and extended spectrum beta-lactamase (ESBL)-producing organisms. The current study aimed at determining the occurrence of metallo beta-lactamase (MBL) and AmpC beta-lactamase (ABL) in gram negative bacteria isolated from clinical samples. A cross-sectional study was conducted amongst the patients visiting Manmohan Memorial Medical College and Teaching Hospital (MMTH), Kathmandu, Nepal from August 2017 to January 2018. A total of 4351 samples including urine, pus, wound swab, endotracheal tip, catheter tip, and blood were collected from the patients and processed by standard conventional microbiological methods. Antibiotic susceptibility testing (AST) of the isolates was performed by Kirby-Bauer disk diffusion method. Double disc synergy test was performed on carbapenem resistant organisms to detect production of MBL and inhibitor-based test was used for the detection of ABL production. Of the 4351 samples, 421 bacterial isolates belonging to 16 different genera were recovered, of which 303 (71.97%) were Gram negative bacilli (GNB). E. coli (189/303) and S. aureus (80/118) were the most prevalent among gram negatives and gram positives, respectively. Bacterial incidence was found significantly associated with gender, specimen type, and the department where the patients were enrolled. Colistin-sulfate and polymycin-B were the most effective drug against GNB, whereas imipenem against gram positives. Prevalence of MDR and methicillin-resistant S. aureus (MRSA) was 35.15% and 60%, respectively. The prevalence of MBL and ABL-producing isolate was 11(3.6%) and 13(4.3%), respectively. Pseudomonas aeruginosa (5/11) and E. coli (9/13) were the major MBL and ABL producers, respectively. MBL and ABL production was found to be significantly associated with the age of the patient and the specimen type. A regular antibiotic surveillance activity with screening for MBL and ABL-producing bacterial isolates in the hospital settings to curb the incidence and transmission of such difficult-to-treat pathogens.

Prevalence of CTX-M β-Lactamases Producing Multidrug Resistant Escherichia coli and Klebsiella pneumoniae among Patients Attending Bir Hospital, Nepal

The emergence of multidrug resistant (MDR) bacteria which is attributable to extended spectrum β-lactamases (ESBLs) production of CTX-M types is an obvious problem worldwide. This study is aimed at determining the prevalence of CTX-M β-lactamases producing multidrug resistant Escherichia coli and Klebsiella pneumoniae among patients attending Bir Hospital. A cross-sectional study was conducted between April and September 2019 at Bir Hospital, Kathmandu, and Department of Microbiology, National College, Kathmandu, Nepal. A total of 5,690 different clinical specimens were subjected to cultural, microscopic, and biochemical analyses for the identification of the isolates. Antimicrobial susceptibility testing of the isolates was done, and MDR isolates were selected and processed for further ESBL confirmation by the combination disks method. All confirmed ESBL isolates were screened for CTX-M type β-lactamases (bla _CTX-M) by PCR. Of the total 345 isolates (227 Escherichia coli and 118 Klebsiella pneumoniae), 232 were MDR. All 232 (67.24%) MDR isolates were suspected as ESBL producers on the screening test. However, on the phenotypic test, 135 (58.18%) of total MDR bacteria were confirmed as ESBL producers with the highest proportion in K. pneumoniae (59.37%). The major source of ESBL producers was urine. ESBL producing isolates were mostly identified from outpatients and patients belonging to age group 41-60. Gentamicin was found to be effective against ESBL producers. The prevalence of bla _CTX-M was (89.62%) with the highest frequency for E. coli (93.81%). High prevalence of ESBL of CTX-M types among MDR E. coli and K. pneumoniae was detected from clinical specimens of patients in Bir Hospital. This study warrants the need for the judicious use of antibiotics as well as emphasize the use of modern diagnostic tools for the early detection of MDR and ESBL producers to curb the emergence and spread of MDR and ESBL producing bacteria in the clinical settings of Nepal.