<p>Virulence and Resistance Determinants of Uropathogenic <em>Escherichia coli</em> Strains Isolated from Pregnant and Non-Pregnant Women from Two States in Mexico</p>

Abstract

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-β-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 βlactam 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 nonpregnant Mexican women.

Bacterial Morphotypes as Important Trait for Uropathogenic E. coli Diagnostic; a Virulence-Phenotype-Phylogeny Study

“…In this study we found that the clinical isolates obtained were predominantly multidrug resistant (93%) and showed a high resistance to antibiotics implemented in the basic treatment of UTI, mainly aminoglycosides, β-lactams, and cotrimoxazole. These results are in agreement with those reported in previous studies [14,16] in Mexico, which highlights the urgent need to search for therapeutic alternatives for the treatment of UTI.…”

“…In Mexico, there are several reports demonstrating the high resistance of clinical isolates of UPEC to this antimicrobial agent which has led to considering its therapeutic efficacy. However, it would be important to continue with research focused on the determination of local susceptibility profiles for the antibiotics included in the basic treatment for UTI in Mexico, since it is known that resistance profiles can differ depending on the geographic area [14,16,[41][42][43][44][45].…”

“…Twenty-five microliters of a 24 h pre-culture in Luria-Bertani broth (LB) of each UPEC isolate were inoculated in a previously created well in 5% sheep blood agar plate and incubated for 24 h at 37 • C. The presence of hemolysis around the inoculated well was considered as a positive phenotype. Escherichia coli CFT073 was used as a positive control, while culture media without bacteria was used as a negative control [14].…”

“…Among these groups, B2 and D are those associated with pathogenic strains for humans, while groups A and B1 are related to both commensal and antibiotic resistance strains [12,13]. However, a high prevalence of UPEC belonging to phylogenetic groups considered to be non-pathogenic has been observed causing disease, which besides their multidrug resistance, also show a significant number of virulence associated genes [14][15][16].…”

Caracterización de cepas de Escherichia coli uropatógena aisladas del tracto urinario de mujeres durante el embarazo

“…Resultados similares fueron reportados por Forson et al (2018) quienes reportaron resistencia a ampicilina (79.3 %), tetraciclina (70.7 %) y trimetoprim/sulfametoxazol (49 %). En estudios previos realizados en México, se observan prevalencias de 100% de resistencia a ampicilina (Ordaz-López et al, 2016;Ballesteros-Monrreal et al, 2020). Diversos reportes en microorganimos Gramnegativos aislados de UTI han demostrado la presencia de β-lactamasas, lo cual se asocia a la alta resistencia a antibióticos β-lactámicos y, particularmente, a ampicilina, carbenicilina y cefalotina, similar a lo reportado en el presente estudio (Ramos et al, 2012;Ifeanyichukwu et al, 2017;Khoshnood et al, 2017;Forson et al, 2018).…”