SAGE Journals; Microbiology Insights "Characteristics of ..................................Kathmandu, Nepal)

 Characteristics of Staphylococcus aureus Isolated From Clinical Specimens in a Tertiary Care Hospital, Kathmandu, Nepal

Shesh Narayan Kandel¹†, Nabaraj Adhikari²†, Binod Dhungel², Upendra Thapa Shrestha², Khadga Bikram Angbuhang¹, Gayatri Karki³, Bipin Adhikari⁴, Megha Raj Banjara², Komal Raj Rijal², Prakash Ghimire²

¹Kantipur College of Medical Sciences, Tribhuvan University, Sitapaila, Kathmandu, Nepal

²Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal

³Himal Hospital, Naxal, Kathmandu, Nepal

⁴Nepal Community Health and Development Centre, Balaju, Kathmandu, Nepal

 

Citation: Kandel et al. Microbiology Insights, 2020, 13: 1–6. DOI: 10.1177/1178636120972695

Article first published online: November 11, 2020; Issue published: January 1, 2020
Received: April 27, 2020; Accepted: October 16, 2020

 

https://creativecommons.org/licenses/by-nc/4.0/This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).

 

 

Abstract

Introduction:

Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen associated with nosocomial and community infections. mecA gene is considered one of the important virulence factors of S. aureus responsible for acquiring resistance against methicillin. The main objective of this study was to explore the prevalence, antibiotic susceptibility pattern, and mec A gene.

Methods:

A total of 39 isolates of S. aureus were isolated from 954 clinical specimens processed in Microbiology laboratory of Himal Hospital, Kathmandu. Antimicrobial susceptibility test (AST) was performed by Kirby-Bauer disc diffusion method using cefoxitin, and performed Polymerase Chain Reaction (PCR) for amplification of mecA gene in MRSA isolates.

Results:

Out of 954 clinical samples, (16.2%; 153/954) samples had bacterial growth. Among 153 culture positive isolates, 25.5% (39/153) were positive for S. aureus. Among 39 S. aureus (61.5%; 24/39) were multiple drug resistant (MDR). On AST, amoxicillin was detected as the least effective while vancomycin was the most effective. The prevalence of methicillin resistance was 46% (18/39) of which 72.2% (13/18) were positive for mecA gene in PCR assay.

Conclusion:

One in 4 culture positive isolates from the clinical specimens were S. aureus, of which almost two-thirds were MDR. Around half of the MDR showed MRSA and significant proportion of them were positive for mecA gene. This study concludes that the mecA gene is solely dependent for methicillin resistance in S. aureus but the presence of gene is not obligatory. PCR detection of the mecA gene is reliable, valid and can be suggested for the routine use in diagnostic laboratories.

Keywords Staphylococcus aureus, MRSA, cefoxitin, mecA gene

 

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"Detection of ........... Infected Chicken Livers in Nepal", animals, an open access journal published by MDPI

 Open AccessArticle

Detection of Plasmid-Mediated Colistin Resistant mcr-1 Gene in Escherichia coli Isolated from Infected Chicken Livers in Nepal

Sayara Bista ^1,†,Upendra Thapa Shrestha ^1,†,Binod Dhungel ¹,Pragya Koirala ²,Tulsi Ram Gompo ²,Nabaraj Shrestha ²,Nabaraj Adhikari ¹,Dev Raj Joshi ¹,Megha Raj Banjara ¹,Bipin Adhikari ³,Komal Raj Rijal ^1,* andPrakash Ghimire ¹

 

¹Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu 44618, Nepal

²Central Veterinary Laboratory Ministry of Agriculture, Land Management and Cooperatives, Government of Nepal, Tripureshwor, Kathmandu 44618, Nepal

³Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 3SY, UK

 

^* Author to whom correspondence should be addressed.

^† These authors have equally contributed in this study.

 

Animals 2020, 10(11), 2060; https://doi.org/10.3390/ani10112060 (registering DOI)

Received: 30 August 2020 / Revised: 22 October 2020 / Accepted: 25 October 2020 / Published: 7 November 2020

(This article belongs to the Special Issue Poultry Microbiology and Immunology)

Simple Summary

The poultry industry is one of the top agribusinesses in Nepal. However, despite the government’s restriction on the use of antibiotics as growth promotors in animals, the overuse and misuse of antibiotics can be seen all over the country. Such inappropriate use of antibiotics has led to the rise of antibiotic resistance among treatment options for both human and animal pathogens. Several findings suggest the failure of colistin, a polymyxin E antibiotic (once regarded as the last resort drug), in the treatment of human bacterial infections is due to the emergence and spread of the plasmid-mediated colistin resistance gene (mcr-1) among Gram-negative bacterial pathogens. The emergence and rapid transfer of resistant strains in poultry farms are associated with unwanted loss of livestock, economic burden and spread of drug-resistance to other animals, humans and the environment, as well. In this study, we characterized the mcr-1 gene from infected chicken livers, where prevalence was found to be alarmingly high. This study identifies the result of regulatory failures. Therefore, this report provides valuable reference to the policy makers so that a more effective policy can be formulated and implemented to curb the spread of drug-resistant pathogens.

Abstract

Background: Plasmid-mediated resistance to the colistin in poultry is considered as an emerging problem worldwide. While poultry constitutes the major industry in Nepal, there is a paucity of evidence on colistin resistance in Escherichia coli isolates causing natural infections in poultry. This study aimed to explore the prevalence of plasmid-mediated colistin resistance gene, mcr-1 in E. coli isolated from liver samples of dead poultry suspected of E. coli infections. 

Methods: A total of two hundred and seventy liver samples (227 broilers and 43 layers) from dead poultry suspected of colibacillosis were collected from post-mortem in the Central Veterinary Laboratory (CVL), Kathmandu, between 1 February and 31 July 2019. The specimens were processed to isolate and identify E. coli; an antimicrobial susceptibility test (AST) using disk diffusion method was performed with 12 different antibiotics: Amikacin (30 µg), ampicillin (10 µg), ciprofloxacin (5 µg), chloramphenicol (30 µg), cefoxitin (30 µg), ceftazidime (30 µg), ceftriaxone (30 µg), cotrimoxazole (25 µg), gentamicin (10 µg), imipenem (10 µg), levofloxacin (5 µg) and tetracycline (30 µg). Colistin resistance was determined by agar dilution method and colistin-resistant strains were further screened for plasmid-mediated mcr-1 gene, using conventional polymerase chain reaction (PCR). 

Results: Out of 270 liver samples, 53.3% (144/270) showed growth of E. coli. The highest number (54%; 109/202) of E. coli isolates was obtained in the liver samples from poultry birds (of both types) aged less than forty days. In AST, 95.1% (137/144) and 82.6% (119/144) of E. coli isolates were resistant against tetracycline and ciprofloxacin, respectively, while 13.2% (19/144) and 25.7% (37/144) isolates were resistant to cefoxitin and imipenem, respectively. In the same assay, 76.4% (110/144) E. coli isolates were multi-drug resistant (MDR). The phenotypic prevalence of colistin resistance was 28.5% (41/144). In the PCR assay, 43.9% (18/41) of colistin-resistant isolates were screened positive for plasmid-mediated mcr-1. 

Conclusion: The high prevalence of mcr-1 in colistin-resistant E. coli isolates in our study is a cause of concern for the probable coming emergence of colistin resistance in human pathogens, due to horizontal transfer of resistant genes from poultry to human isolates.

 Keywords: Escherichia coli; colistin resistance; MDR; mcr-1

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Biofilm and MBL production among imipenem resistant Pseudomonas aeruginosa and Acinetobacter species

 

ISSN 2449-8947                   MicroMedicine                   Research Article

 

MicroMedicine 2020; 8(2): 63-73

 

DOI: http://dx.doi.org/10.5281/zenodo.4195479

 

Biofilm and MBL production among imipenem resistant Pseudomonas aeruginosa and Acinetobacter species

Yang Metok, Supram Hosuru Subramanya, Upendra Thapa Shrestha, Leandro Reus Rodrigues Perez, Nabaraj Adhikari, Niranjan Nayak

 

ABSTRACT:

 

Pseudomonas aeruginosa and Acinetobacter species are the primary cause of nosocomial infections. The advent of Metallo-beta-lactamase (MBL) and biofilm-producing bacterial strains poses a serious threat to reserve drugs such as carbapenem. The objective of this study was to determine the rate of MBL and biofilm production among imipenem resistant P. aeruginosa (IRPA) and imipenem resistant Acinetobacter spp. (IRAS) isolates. A total of 79 P. aeruginosa and 117 Acinetobacter spp. were isolated from various clinical specimens of patients from July 2016 to January 2017 at Manipal Teaching Hospital, Pokhara. MBL in IRPA and IRAS isolates were detected by Combined disc test and E-test. Biofilm production in imipenem resistant isolates was carried out by Microtitre plate assay. Fifteen (19%) P. aeruginosa and 57 (48.7%) Acinetobacter spp. were imipenem resistant isolates. MBL producers were found among 53.3% of IRPA and 38.6% of IRAS, whereas 100% of IRPA and 82.5% of IRAS were biofilm producers. All the biofilm producer IRPA isolates were Extensively Drug-Resistant (XDR), and a larger proportion of XDR IRAS strains were of high biofilm-producing phenotype. However, the majority of imipenem resistant (80% of IRPA and 49.1% of IRAS) and MBL producing (63%) isolates were weak biofilm formers. The study demonstrated the high capability of IRPA and IRAS to form a biofilm, which was strongly related to higher drug resistance. Nonetheless, imipenem resistant and MBL producer isolates showed an analogous association with the degree of biofilm formation. These MBL cum biofilm producer isolates were better susceptible to polymyxin B and ampicillin-sulbactam.

 

Keywords: Pseudomonas aeruginosa; Acinetobacter spp.; Imipenem-resistance; MBL; Biofilm.

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