Antibiotic Resistance Patterns of Diverse Escherichia coli Phylogenetic Groups Isolated from the Al-Hillah River in Babylon Province, Iraq

A review of organophosphonates, their natural and anthropogenic sources, environmental fate and impact on microbial greenhouse gases emissions - Identifying knowledge gaps

Organophosphonates (OPs) are a unique group of natural and synthetic compounds, characterised by the presence of a stable, hard-to-cleave bond between the carbon and phosphorus atoms. OPs exhibit high resistance to abiotic degradation, excellent chelating properties and high biological activity. Despite the huge and increasing scale of OP production and use worldwide, little is known about their transportation and fate in the environment. Available data are dominated by information concerning the most recognised organophosphonate - the herbicide glyphosate - while other OPs have received little attention. In this paper, a comprehensive review of the current state of knowledge about natural and artificial OPs is presented (including glyphosate). Based on the available literature, a number of knowledge gaps have been identified that need to be filled in order to understand the environmental effects of these abundant compounds. Special attention has been given to GHG-related processes, with a particular focus on CH4. This stems from the recent discovery of OP-dependent CH4 production in aqueous environments under aerobic conditions. The process has changed the perception of the biogeochemical cycle of CH4, since it was previously thought that biological methane formation was only possible under anaerobic conditions. However, there is a lack of knowledge on whether OP-associated methane is also formed in soils. Moreover, it remains unclear whether anthropogenic OPs affect the CH4 cycle, a concern of significant importance in the context of the increasing rate of global warming. The literature examined in this review also calls for additional research into the date of OPs in waste and sewage and in their impact on environmental microbiomes.

Detection and genetic analysis of Escherichia coli from Tonle Sap Lake and its tributaries in Cambodia: Spatial distribution, seasonal variation, pathogenicity, and antimicrobial resistance

As an indicator of fecal contamination, Escherichia coli was monitored in Tonle Sap Lake, Cambodia, and its tributaries during low- and high-water seasons, focusing on the impacts on floating villagers inhabiting boathouses. E. coli concentrations in the floating villages (3.6 × 10³ and 5.7 × 10³ CFU/100 mL during the low- and high-water seasons, respectively) were significantly higher than those in other lake sites (4.0 × 10¹ and 7.0 × 10⁰ CFU/100 mL during the low- and high-water seasons, respectively) and rivers (3.3 × 10² and 8.9 × 10² CFU/100 mL during the low- and high-water seasons, respectively), most likely because fecal materials from the boathouses were discharged without treatment. At most of the lake sampling sites remote from the boathouses, the E. coli concentration was lower during the high-water season than that during the low-water season, due to dilution by lake water. E. coli colonies detected during monitoring were isolated for pathotyping, antimicrobial susceptibility testing, beta-lactamase gene detection, and multilocus sequencing typing (MLST). Of the 659 E. coli isolates, 101 (15.3%) were diarrheagenic E. coli (DEC). The prevalence of DEC (52.2%) in the floating villages during the low-water season was higher than that during the high-water season (4.2%) and that in other sites during both seasons (10.6-21.3%). The DEC isolates from the floating villages during the low-water season showed high antimicrobial resistance, including ampicillin (83.4%) and ciprofloxacin (83.4%), and frequently possessed a beta-lactamase gene (bla_TEM) (83.4%). MLST analysis indicated that the predominant sequence type (ST) of DEC isolates from the floating villages possibly originated from humans, whereas more diverse STs were detected in isolates from other sites. We revealed the wide presence of diarrheagenic and antimicrobial-resistant E. coli in Tonle Sap Lake and identified a considerable infection risk in floating villages, especially during the low-water season.

Characterization of Multidrug-Resistant Escherichia coli Isolated from Two Commercial Lettuce and Spinach Supply Chains

ABSTRACT

Leafy green vegetables have increasingly been reported as a reservoir of multidrug-resistant pathogenic Enterobacteriaceae, with Shiga toxin-producing Escherichia coli frequently implicated in disease outbreaks worldwide. This study examined the presence and characteristics of antibiotic resistance, diarrheagenic virulence genes, and phylogenetic groupings of E. coli isolates (n = 51) from commercially produced lettuce and spinach from farms, through processing, and at the point of sale. Multidrug resistance was observed in 33 (64.7%) of the 51 E. coli isolates, with 35.7% (10 of 28) being generic and 100% (23 of 23) being extended-spectrum β-lactamase/AmpC producing. Resistance of E. coli isolates was observed against neomycin (51 of 51, 100%), ampicillin (36 of 51, 70.6%), amoxicillin (35 of 51, 68.6%), tetracycline (23 of 51, 45%), trimethoprim-sulfamethoxazole (22 of 51, 43%), chloramphenicol (13 of 51, 25.5%), Augmentin (6 of 51, 11.8%), and gentamicin (4 of 51, 7.8%), with 100% (51 of 51) susceptibility to imipenem. Virulence gene eae was detected in two E. coli isolates from irrigation water sources only, whereas none of the other virulence genes for which we tested were detected. Most of the E. coli strains belonged to phylogenetic group B2 (25.5%; n = 13), B1 (19.6%; n = 10), and A (17.6%; n = 9), with D (5.9%; n = 3) less distributed. Although diarrheagenic E. coli was not detected, antibiotic resistance in E. coli prevalent in the supply chain was evident. In addition, a clear link between E. coli isolates from irrigation water sources and leafy green vegetables through DNA fingerprinting was established, indicating the potential transfer of E. coli from irrigation water to minimally processed leafy green vegetables.

HIGHLIGHTS

Quinolone resistance (qnrA) gene in isolates of Escherichia coli collected from the Al-Hillah River in Babylon Province, Iraq

Aquatic environment contamination remains a foremost global public health hazards, and symbolizes a significant reservoir of releasing antibiotic resistant bacteria. The survival of Escherichia coli in aquatic environments serves as a potential reservoir of antibiotic resistance, encompassing but not restricted to a plasmid-mediated quinolone resistance (PMQR) mechanism. The current study aimed to detect the presence of the PMQR-qnrA gene in quinolone-resistant E. coli isolates. Sixty-one waterborne E. coli with known phylogroups/subgroups isolated from the Al-Hillah River in Babylon Province, Iraq, were screened for the phenotypic resistance to third-generation quinolones (levofloxacin and ofloxacin) and were further analysed for the presence of the qnrA gene using polymerase chain reaction (PCR). Fifty-seven (93.4%) of 61 E. coli isolates were levofloxacin-resistant, and 55 (90.2%) were ofloxacin-resistant. Among the 57 quinolone-resistant E. coli, 40 (65.57%) isolates were found to carry the PMQR-qnrA gene. Among the 40 qnrA-positive E. coli, 22 (36.1%) isolates were in phylogroup B2, followed by 8 (13.1%) isolates in phylogroup D, 6 (9.8%) isolates in phylogroup B1, and 4 (6.6%) isolates in phylogroup A. The presence of the PMQR-qnrA gene in E. coli belonging to phylogroup B2 and D reflects the need for routine monitoring of antibiotic resistance genes (ARGs) in the Al-Hillah River.

Patterns of antimicrobial resistance observed in the Middle East: Environmental and health care retrospectives

Antimicrobial resistance is one of the biggest worldwide challenging problems that associates with high morbidity and mortality rates. The resistance of bacteria to various antibiotic classes results in difficulties in the treatment of infectious diseases caused by those bacteria. This paper highlights and provides a critical overview of observational and experimental studies investigating the presence of antibiotic resistant bacteria in different environments in Middle East countries and the mechanisms by which bacteria acquire and spread resistance. The data of this research considered the published papers within the last ten years (2010-2020) and was carried out using PubMed. A total of 66 articles were selected in this review. This review covered studies done on antibiotic resistant bacteria found in a wide range of environments including foods, animals, groundwater, aquatic environments as well as industrial and hospital wastewater. They acquire and achieve their resistance through several mechanisms such as antibiotic resistant genes, efflux pumps and enzymatic reactions. However, the dissemination and spread of antibiotic resistant bacteria is affected by several factors like anthropogenic, domestic, inappropriate use of antibiotics and the expulsion of wastewater containing antibiotic residues to the environments. Therefore, it is important to increase the awareness regarding these activities and their effect on the environment and eventually on health.