Genotypic Characterization of Aminoglycoside Resistance Genes from Bacteria Isolates in Selected Municipal Drinking Water Distribution Sources in Southwestern Nigeria

Abstract

BACKGROUND: Multi-drug Resistant (MDR) bacteria could lead to treatment failure of infectious diseases and could be transferred by non-potable water. Few studies have investigated occurrence of Antibiotic Resistance Genes (ARGs) among bacteria including Aminoglycoside Modifying Genes (AMGs) from Drinking Water Distribution Systems (DWDS) in Nigeria. Here, we aimed at characterization of AMGs from DWDS from selected states insouthwestern Nigeria.METHODS: One hundred and eighty one (181) MDR bacteria that had been previously characterized using 16S rDNA and showed resistance to at least one aminoglycoside antibiotic were selected from treated and untreated six water distribution systems in southwestern Nigeria. MDR bacteria were PCR genotyped for three AMGs:aph (3´´)c, ant (3´´)b and aph(6)-1dd.RESULTS: Out of 181 MDR bacteria genotyped, 69(38.12%) tested positive for at least one of the genotyped AMGs. Highest (50, 27.62%) detected gene was ant (3”)c followed by aph (3")c(33,18.23%). Combination of aph(3")c and ant (3")b in a single bacteria was observed as the highest (14, 7.73%) among the detected gene combination. Alcaligenes sp showed the highest (10/20) occurrence of ant (3")b while aph(3")c was the highest detected among Proteussp (11/22). Other bacteria that showed the presence of AMGs include: Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter and Serratia.CONCLUSIONS: High occurrence of ant (3”)c and aph (3”)c among these bacteria call for urgent attention among public health workers, because these genes can be easily disseminated to consumers of these water samples if present on mobile genetic elements like plasmids, integrons and transposons.

Taxonomic Identification of Different Species of the Genus Aeromonas by Whole-Genome Sequencing and Use of Their Species-Specific β-Lactamases as Phylogenetic Markers

“…carrying sul1 exhibited increased MICs for sulfamethoxazole treatments. Aminoglycoside resistance genes found in strain D549 [ aph(3 ′′ )1b and aph(3 ′′ )1d )] match previous reports on Aeromonas [ 24 , 40 ], whereas we were unable to find publications mentioning aadA2, as we found in strain D552.…”

“…However, we did not find any qnr -like genes among the resistant isolates D549-D553, correlating with the findings of Ghatak et al [ 27 ]. Additionally, we found D549-D552 to have point mutations in gyr A resulting in amino acid substitution (Ser83Ile) and par C (Ser80Ile), which are typically associated with quinolone-resistant aeromonads [ 40 , 41 ], as well as a mutation in gyrA : Ser83Arg in strain D553 not previously reported in Aeromonas spp.…”

Virulence and antimicrobial resistance potential ofAeromonasspp. associated with shellfish

“…Genes encoding aminoglycosides are one of the broadly variated gene groups that have been detected in Aeromonas spp. which possess the inhabitation of protein synthesis to perform antimicrobial activities in the bacteria (Timilehin et al 2019). Table 2 indicates some studies related to the prevalence of antimicrobial resistance genes in shellfish.…”

“…which possess the inhabitation of protein synthesis to perform antimicrobial activities in the bacteria (Timilehin et al . 2019). Table 2 indicates some studies related to the prevalence of antimicrobial resistance genes in shellfish.…”