Extended-Spectrum β-Lactamase-ProducingKlebsiella pneumoniaefrom Pharmaceutical Wastewaters in South-Western Nigeria

Abstract

Emergence and spread of Klebsiella pneumoniae isolates producing extended-spectrum β-lactamases (ESBLs) present a major threat to public health. In this study, we characterized β-lactam-resistant K. pneumoniae isolates from six wastewater samples obtained from two pharmaceutical industries located in Lagos and Ogun States, Nigeria. Bacteria were isolated by using MacConkey agar; species identification and antibacterial susceptibility testing were performed by Vitek 2. Etest was used for ESBL phenotype confirmation. The presence of β-lactamase genes was investigated by PCR and sequencing. Bacterial strain typing was done by XbaI-macrorestriction and subsequent pulsed-field gel electrophoresis (PFGE) as well as multilocus sequence typing (MLST). Thirty-five bacterial species were isolated from the six samples; among them, we identified seven K. pneumoniae isolates with resistance to β-lactams and co-resistance to fluoroquinolones, aminoglycosides, and folate pathway inhibitors. The ESBL phenotype was confirmed in six K. pneumoniae isolates that harbored ESBL genes bla (n = 5), bla (n = 1), and bla (n = 1). PFGE and MLST analysis revealed five clones belonging to four sequence types (ST11, ST15, ST37, ST101), and clone K. pneumoniae-ST101 was present in the wastewater samples from two different pharmaceutical industries. Additionally performed conjugation assays confirmed the location of β-lactamase genes on conjugative plasmids. This is the first confirmation of K. pneumoniae isolates producing CTX-M-15-ESBL from pharmaceutical wastewaters in Nigeria. The co-resistance observed might be a reflection of the different drugs produced by these industries. Continuous surveillance of the environmental reservoirs of multidrug-resistant bacteria is necessary to prevent their further spread.

A survey of extended-spectrum beta-lactamase-producing Enterobacteriaceae in urban wetlands in southwestern Nigeria as a step towards generating prevalence maps of antimicrobial resistance

“…Thirty-five of the isolated 3GC-RB tested positive for ESBL production and were identified by partial 16S rRNA sequencing as belonging to the Enterobacteriaceae genera Escherichia (7 strains), Enterobacter (4 strains), and Citrobacter (1 strain), and to the "Pseudomonas putida group" [42,43] (10 strains; all with >99% identity to P. monteilii, P. taiwanensis, and P. plecoglossicida), Caulobacter (9 strains; about 95% identity with C. segnis), Achromobacter (2 strains; 98.61% identity with A. insuavis, and 99.12% identity with A. spanius, respectively), and Stenotrophomonas (2 strains; >99% similarity with S. pavanii). ESBL-producing bacteria have been isolated from aquatic ecosystems in different parts of the world [44][45][46][47][48][49] including Nigeria [9,50], in particular from sites were insufficiently treated wastewater is released into the aquatic environment.…”

Whole genome sequencing snapshot of multi-drug resistant Klebsiella pneumoniae strains from hospitals and receiving wastewater treatment plants in Southern Romania

“…Our study reveals for the first time the presence of carbapenemases-producing K. pneumoniae ST35, ST219, ST364, ST395, ST485 and ST1878 in wastewaters, of which ST395 has clinical importance, while ST35 and ST485 are sporadically related to clinical cases. The other STs, with major clinical significance, have already been described in wastewaters: ST11 [5,41,42,43], ST17 [44], ST45 [45], ST101 [43,46,47,48], ST258 [49], ST307 [45,49,50,51], ST512 [52], and the minor clone ST1564 [45].…”

High abundances of class 1 integrase and sulfonamide resistance genes, and characterisation of class 1 integron gene cassettes in four urban wetlands in Nigeria

“…A few previous studies have reported the detection of clinically relevant ARG in cultivable bacteria isolated from environmental sources in Nigeria [28,29,30,31], but none that we know of used culture-independent quantification to assess the contamination of the Nigerian wetland ecosystems with ARGs. The purpose of this study was to quantify the copy numbers of sul1, sul2, and class 1 integrase gene (intI1) as markers for ARG contamination in the sediments of four polluted wetlands located in Lagos and Ibadan, two of Africa's most populous cities.…”