Detection of Plasmid Borne Extended Spectrum Beta Lactamase Enzymes from Blood and Urine Isolates of Gram-Negative Bacteria from a University Teaching Hospital in Nigeria

Antibiogram and Molecular Characterization of AmpC and ESBL-Producing Gram-Negative Bacteria from Poultry and Abattoir Samples

BACKGROUND AND OBJECTIVE

The global antibiotic resistance threat posed by ESBL and AmpC-producing Gram-Negative Bacteria (GNB) is a public health menace that rolls back the gains of 'One Health'. This study investigated the antibiogram and prevalence of AmpC and ESBL genes in Escherichia coli, Klebsiella spp. and Pseudomonas spp. from poultry and abattoir milieus in Enugu and Ebonyi States, Nigeria.

MATERIALS AND METHODS

Isolation, identification and characterization of GNB from samples (150 abattoirs and 300 poultry) were done using standard microbiological techniques. Antimicrobial Susceptibility Testing (AST), as well as phenotypic screening for ESBL and AmpC enzymes, was performed using the Kirby-Bauer disc diffusion technique. PCR technique was used to screen isolated GNB for AmpC and ESBL genes.

RESULTS

Exactly 42 E. coli and 8 Klebsiella spp. isolate from poultry samples and another 5 P. aeruginosa isolates from abattoir samples were phenotypically confirmed to be ESBL-producers. AmpC enzymes were phenotypically detected in 8 E. coli and 13 P. aeruginosa isolates from poultry samples. All ESBL and AmpC-positive bacteria exhibited high resistance frequencies to tested antibiotics, especially to the carbapenems and cephalosporins. ESBL genes (CTX-M, SHV-1, TEM) and AmpC genes (ACC-M, MOX-M, DHA-M) were harbored by the isolated GNB in this study. Overall, the DHA-M and CTX-M genes, mediating AmpC and ESBL production respectively were the most prevalent genes harbored by the tested GNB.

CONCLUSION

This study reported that AmpC and ESBL genes are harbored by Gram-negative bacteria (E. coli, Klebsiella species and P. aeruginosa) that emanated from poultry and abattoir milieus.

A systematic review on the prevalence of extended-spectrum beta lactamase-producing Gram-negative bacteria in Nigeria

OBJECTIVE

There are numerous reported cases of extended-spectrum beta-lactamases (ESBLs) producing Enterobacteriaceae in Nigeria. Yet, there are regions in Nigeria where cases of ESBL were under-reported. The review aims to assess the prevalence of ESBL-producing Gram-negative bacteria in Nigeria and the genes involved.

METHODS

An extensive literature search was carried out through an electronic database including PubMed, Scopus, Google Scholar and African Journals Online (AJOL). Articles published between January 2004 and November 2019 were included in the study. The titles and abstracts of the retrieved articles were reviewed, and then the full texts of the selected articles were reviewed. Articles were divided according to geopolitical zones.

RESULTS

Among the 217 articles identified, 60 studies (10 from north-central, 4 from northeast, 7 from the northwest, 17 from the southeast, 10 from south-south, and 12 from southwest Nigeria) were included. The highest prevalence recorded was 82.3%, while the lowest was 7.5%. The genes TEM, SHV, and CTX-M were the predominant variant commonly found. The most frequently used phenotypic detection method is the double disc synergy test (DDST).

CONCLUSION

ESBL-producing Gram-negative bacteria in hospital and community settings in Nigeria were commonly found. The prevalence of ESBL is very high, with one of the geopolitical zones under-reported. Future research should be conducted in these zones where there are scant studies, and a holistic approach involving the clinicians, researchers, laboratory scientists, and patients will go a long way in reducing the dissemination of this resistance mechanism.

Characterization of enteropathogenic Escherichia coli of clinical origin from the pediatric population in Pakistan

BACKGROUND

Enteropathogenic Escherichia coli (EPEC) is one of the leading causes of watery diarrhea among children.

METHODS

In this study EPEC isolates from the pediatric population of Pakistan (2010-2012) were subjected to phylotyping, antibiotic susceptibility, extended-spectrum beta-lactamase (ESBL) profiling and evaluation of one representative strain from each panel of phylotypesin Galleria mellonella, infection model.

RESULTS

A total of 46/225 (20.4%) stool samples were positive for EPEC. Isolates mainly belong to D phylogroup (18, 39%) followed by nontypeable (10, 22%), B1 (9, 20%), B2 (8, 17%) and A (1, 2%). High resistance was observed for ampicillin (42, 91%), erythromycin (41, 89%), cefaclor (37, 80%), trimethoprim/sulfamethoxazole (36, 78%), tetracycline (36, 78%). Among nalidixic acid resistant isolates 13 (28%) showed presence of single nucleotide polymorphism (SNP) in parC (C330-T330) whereas 1 (2%) isolate showed gyrB (A660-T660) SNP. Furthermore, 27 (59%) isolates were ESBL producers. Representative isolates of phlyotypes A and B2 showed enhance killing of G. mellonella compared to ones belonging to phylotypes B1 and D.

CONCLUSIONS

Non-typeable EPEC strains were frequently observed. ESBL production in ESBL producers was found to be plasmid mediated. No significant association of antibiotic resistance profile with specific phylogroup of EPEC was found, however G. mellonella infection model differentiated representative phylotypes.

A Multicenter Study of Beta-Lactamase Resistant Escherichia coli and Klebsiella pneumoniae Reveals High Level Chromosome Mediated Extended Spectrum β Lactamase Resistance in Ogun State, Nigeria

As a result of the ever increasing problem of multiresistant bacteria, we instituted a surveillance program with the aim of identifying the basic molecular properties of ESBL in our environment. About 197 isolates of Escherichia coli and Klebsiella pneumoniae were selected and tested for ESBL production and antimicrobial susceptibility. Plasmid profiles were determined and curing ability was tested. ESBL prevalence was 26.4% for all isolates tested, with E. coli having a greater proportion. There was absolute resistance to ampicilin, tetracycline, and co-trimaxole among tested isolates. There was above average susceptibility to the 2nd and 3rd generation cephalosporins. Plasmid profiles of tested isolates ranged from 9 kbp to 26 kbp with average of 14.99 ± 2.3 kbp for E. coli and 20.98 ± 1.8 kbp K. pneumoniae, 9.6% of ESBL positive E. coli plasmids were cured, while 3.9% of K. pneumoniae plasmids were cured after treatment. The present study shows an upsurge in ESBL acquisition by gram negative bacteria and evidence of cocirculation of varying subtypes of ESBL with both plasmid transmissible and chromosome encoded subtypes. This calls for universal surveillance and more effort towards molecular epidemiology of this public health treatment.