Resistance phenotype and virulence potential of Leclercia adecarboxylata strains isolated from different sources.

Introduction. Leclercia adecarboxylata is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted L. adecarboxylata as an emerging pathogen harbouring virulence and resistance determinants.Gap statement. Little information exists on virulence and resistance determinants in L. adecarboxylata strains isolated from environmental, food, and clinical samples.Aim. To determine the presence of resistance and virulence determinants and plasmid features in L. adecarboxylata strains isolated from environmental, food, and clinical samples, as well as their phylogenetic relationship.Results. All strains tested showed resistance to ß-lactams and quinolones but were sensitive to aminoglycosides and nitrofurans. However, even though fosfomycin resistance is considered a characteristic trait of L. adecarboxylata, the resistance phenotype was only observed in 50 % of the strains; bla TEM was the most prevalent BLEE gene (70 %), while the quinolone qnrB gene was observed in 60 % of the strains. Virulence genes were differentially observed in the strains, with adhesion-related genes being the most abundant, followed by toxin genes. Finally, all strains carried one to seven plasmid bands ranging from 7 to 125 kbps and harboured several plasmid addiction systems, such as ParDE, VagCD, and CcdAB in 80 % of the strains.Conclusions. L. adecarboxylata is an important emerging pathogen that may harbour resistance and virulence genes. Additionally, it has mobilizable genetic elements that may contribute to the dissemination of genetic determinants to other bacterial genera.

Uropathogenic Escherichia coli in Mexico, an Overview of Virulence and Resistance Determinants: Systematic Review and Meta-analysis.

BACKGROUND: Urinary tract infections (UTI) are one of the most common pathologies in Mexico and the majority are caused by uropathogenic Escherichia coli (UPEC). UPEC possesses virulence and resistance determinants that promote UTI development and affect diagnosis and treatment. This study aims to systematically review published reports of virulence genes, antibiotic resistance, and phylogenetic groups prevalent in clinical isolates of UPEC in the Mexican population. METHODS: Systematic review with meta-analysis was performed following PRISMA guidelines. Articles in both English and Spanish were included. Total prevalence with a 95% confidence interval of each characteristic was calculated. Heterogeneity between studies and geographical areas was assessed by the Cochran Q test (Q), I-square (I2), and H-square (H2). Egger's test was used for risk of bias in publications and asymmetry evaluations. RESULTS: Forty-two articles were analyzed. The most prevalent virulence genes were ecp (97.25%; n = 364) and fimH (82.34%; n = 1,422), which are associated with lower UTI, followed by papGII (40.98%; n = 810), fliC (38.87%; n = 319), hlyA (23.55%; n = 1,521), responsible for with upper UTI. More than 78.13% (n = 1,893) of the isolates were classified as multidrug-resistant, with a higher prevalence of resistance to those antibiotics that are implemented in the basic regimen in Mexico. The most frequently reported Extended Spectrum ß-Lactamase (ESBL) was CTX-M-1 (55.61%; n = 392), and the predominant phylogroup was B2 (35.94%; n = 1,725). CONCLUSION: UPEC strains are responsible for a large portion of both lower and upper UTI in Mexico, and their multi-drug resistance drastically reduces the number of therapeutic options available.

Prevalence of Antibiotic-Resistant E. coli Strains in a Local Farm and Packing Facilities of Honeydew Melon in Hermosillo, Sonora, Mexico.

Pathogenic strains of Escherichia coli threaten public health due to their virulence factors and antibiotic resistance. Additionally, the virulence of this bacterium varies by region depending on environmental conditions, agricultural practices, and the use of antibiotics and disinfectants. However, there is limited research on the prevalence of antibiotic-resistant E. coli in agriculture. Therefore, this research aimed to determine the antibiotic resistance of E. coli isolated from the Honeydew melon production system in Hermosillo, Sonora, Mexico. Thirty-two E. coli strains were isolated from 445 samples obtained from irrigation water, harvested melons, the hands of packaging workers, boxes, and discarded melons. The resistance profile of the E. coli strains was carried out to 12 antibiotics used in antimicrobial therapeutics against this bacterium; a high level of resistance to ertapenem (100%) was detected, followed by meropenem (97%), and ampicillin (94%); 47% of the strains were classified as multidrug-resistant. It was possible to identify the prevalence of the extended-spectrum ß-lactamase (ESBLs) gene blaTEM (15.6%), as well as the non-ESBL genes qepA (3.1%) and aac(6')lb-cr (3.1%). The E. coli strains isolated from irrigation water were significantly associated with resistance to aztreonam, cefuroxime, amikacin, and sulfamethoxazole/trimethoprim. Irrigation water, packing workers' hands, and discarded melons showed a higher prevalence of antibiotic-resistant, ESBL, and non-ESBL genes of E. coli strains in a farm and packing facility of Honeydew melon in Hermosillo, Sonora.

Characterization of Diarreaghenic Escherichia coli Strains Isolated from Healthy Donors, including a Triple Hybrid Strain.

Escherichia coli is a well-recognized inhabitant of the animal and human gut. Its presence represents an essential component of the microbiome. There are six pathogenic variants of E. coli associated with diarrheal processes, known as pathotypes. These harbor genetic determinants that allow them to be classified as such. In this work, we report the presence of diarrheagenic pathotypes of E. coli strains isolated from healthy donors. Ninety E. coli strains were analyzed, of which forty-six (51%) harbored virulence markers specifics for diarrheagenic pathotypes, including four hybrids (one of them with genetic determinants of three DEC pathotypes). We also identified phylogenetic groups with a higher prevalence of B2 (45.6%) and A (17.8%). In addition, resistance to sulfonamides (100%), and aminoglycosides (100%) was found in 100% of the strains, with a lower prevalence of resistance to cefotaxime (13.3%), ceftriaxone (12.2%), fosfomycin (10%), and meropenem (0%). All analyzed strains were classified as multidrug resistant. Virulence genes were also investigated, which led us to propose three new virotypes. Among the virulence traits observed, the ability to form biofilms stands out, which was superior to that of the E. coli and Staphylococcus aureus strains used as positive controls.

Relevance of tracking the diversity of Escherichia coli pathotypes to reinforce food safety.

Escherichia coli is among the most prevalent food contaminant microorganisms that have evolved, generating variants based on their effects on the host; these include commensals or pathobiont strains. The last classifications of E. coli intestinal pathobionts found in this review are enteroinvasive, enterohemorrhagic, enteropathogenic, enterotoxigenic, diffusely adherent, and enteroaggregative strains. Meanwhile, the most ancestral are enteropathogenic and enteroaggregative, and the most contemporaries are the enterotoxigenic and enteroinvasive strains. These pathobionts have been proposed based on their infective mechanisms, including toxin production, adherence effects, and tissue damage. It is also evidenced that environmental stresses, including bacterial exposition to antibiotics and disinfectants, contribute to this evolution. Therefore, new antibacterial and antivirulence agents are being explored, mainly from natural sources. In this context, this review discusses the diversity of E. coli pathobionts, their participation in foodborne outbreaks, and strategies to survey and control their spread and virulence.

Virulence and Resistance Determinants of Uropathogenic Escherichia coli Strains Isolated from Pregnant and Non-Pregnant Women from Two States in Mexico.

BACKGROUND/PURPOSE: Uropathogenic E. coli (UPEC) is the main cause of urinary tract infection (UTI) and it is known that pregnant women have a higher risk for UTI. UPEC has a variety of virulence and antibiotic resistance factors that facilitate its pathogenic success and it is crucial to know which are the susceptibility patterns, Extended-Spectrum-ß-Lactamase (ESBL) production, virulence genes, pathogenicity islands (PAI), phylogenetic groups and serotypes among strains isolated from pregnant and non-pregnant women. METHODS: One hundred fifty UPEC strains were isolated from pregnant and non-pregnant women from two different Mexican states (Sonora and Puebla). Strains were analyzed using the Kirby-Bauer method for the determination of antibiotic susceptibility and ESBL. Virulence genes, PAIs and phylogenetic groups were determined using a multiplex PCR. Strains were serotyped by an agglutination assay. Blood agar and CAS agar were used for phenotypic assays. RESULTS: 92.7% of UPEC strains showed multidrug-resistant (MDR), 6.7% extremely-resistant (XDR) and 0.6% pandrug-resistant (PDR). The highest resistance was determined to be for ß-lactam antibiotics (>72% in both states) and 44.5% of the UPEC strains were ESBL+. The predominant virulence genes found were fimH (100%), iucD (85%) and iha (60%). The strains isolated from pregnant women from Puebla presented a large percentage of genes associated with upper urinary tract infections. PAIs were found in 51% and 68% of the strains from Sonora and Puebla, respectively. All the strains were siderophores producers and 41.5% produced hemolysis. The serotypes found were diverse and belonged to phylogroups A, B2 and C. CONCLUSION: The UPEC strains from this study are MDR with tendency to XDR or PDR, they can cause upper UTIs and are serotypically and phylogenetically diverse, which supports the need to develop new strategies for UTI treatment in pregnant and non-pregnant Mexican women.