Distribution of Beta-Lactamase Producing Gram-Negative Bacterial Isolates in Isabela River of Santo Domingo, Dominican Republic

Abstract

Bacteria carrying antibiotic resistance genes (ARGs) are naturally prevalent in lotic ecosystems such as rivers. Their ability to spread in anthropogenic waters could lead to the emergence of multidrug-resistant bacteria of clinical importance. For this study, three regions of the Isabela river, an important urban river in the city of Santo Domingo, were evaluated for the presence of ARGs. The Isabela river is surrounded by communities that do not have access to proper sewage systems; furthermore, water from this river is consumed daily for many activities, including recreation and sanitation. To assess the state of antibiotic resistance dissemination in the Isabela river, nine samples were collected from these three bluedistinct sites in June 2019 and isolates obtained from these sites were selected based on resistance to beta-lactams. Physico-chemical and microbiological parameters were in accordance with the Dominican legislation. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses of ribosomal protein composition revealed a total of 8 different genera. Most common genera were as follows: Acinetobacter (44.6%) and Escherichia (18%). Twenty clinically important bacterial isolates were identified from urban regions of the river; these belonged to genera Escherichia (n = 9), Acinetobacter (n = 8), Enterobacter (n = 2), and Klebsiella (n = 1). Clinically important multi-resistant isolates were not obtained from rural areas. Fifteen isolates were selected for genome sequencing and analysis. Most isolates were resistant to at least three different families of antibiotics. Among beta-lactamase genes encountered, we found the presence of blaTEM, blaOXA, blaSHV, and blaKPC through both deep sequencing and PCR amplification. Bacteria found from genus Klebsiella and Enterobacter demonstrated ample repertoire of antibiotic resistance genes, including resistance from a family of last resort antibiotics reserved for dire infections: carbapenems. Some of the alleles found were KPC-3, OXA-1, OXA-72, OXA-132, CTX-M-55, CTX-M-15, and TEM-1.

Antimicrobial Susceptibility Profiles of Bacteria Isolated from The Ozama River in Santo Domingo, Dominican Republic

“…Also, these isolates tested positive for broad-spectrum beta-lactamase genetic markers. We found similar resistance diversity to those presented in previous studies based on antibiotic resistance assays performed with ciprofloxacin, gentamicin, and trimetho-prim/sulfamethoxazole (6).…”

“…Our sampling strategy and naming scheme consisted of three primary regions; s Submission Template mSystems Submission Template mSystems Submission Template mSystems Submission Template mSystems Submission Template mSystems Submission Te we named them: point A, corresponding to Cañada la Rubia, an area where a highly populated zone discharges waste; B, the river delta, near the confluence with Isabela River (6); and C, near its source. Each point was sampled three times, corresponding to replicas one, two, and three.…”

“…As a result, they have propelled their abundance in the environment (6). However, if performed irresponsibly, these practices lead to inadequate disposal of antibiotics and other pollutants directly to essential water sources.…”

“…The adoption of antibiotics to prevent and treat infections in the animal husbandry industry and their use at sub-therapeutic concentrations are growth promoters for agriculture (1, 2, 3, 4, 5). As a result, they have propelled their abundance in the environment (6). However, if performed irresponsibly, these practices lead to inadequate disposal of antibiotics and other pollutants directly to essential water sources.…”

“…A previous study (6), was examined the dissemination of resistance to beta-lactams in the bacterial communities present in the Isabela River, the main tributary of the Ozama River. This tributary is also highly impacted by anthropogenic action.…”