Cervico-vaginopathogenic Escherichia coli in Iran: Serogroup distributions, virulence factors and antimicrobial resistance properties

Virulence gene transcription, phylogroups, and antibiotic resistance of cervico-vaginal pathogenic E. coli in Mexico

The pathogenicity of Escherichia coli strains that cause cervico-vaginal infections (CVI) is due to the presence of several virulence genes. The objective of this study was to define the variability regarding the genotype of antibiotic resistance, the transcription profiles of virulence genes after in vitro infection of the vaginal cell line A431 and the phylogroup composition of a group of cervico-vaginal E. coli strains (CVEC). A total of 200 E. coli strains isolated from Mexican women with CVI from two medical units of the Mexican Institute of Social Security were analysed. E. coli strains and antibiotic resistance genes were identified using conventional polymerase chain reaction (PCR), and phylogroups were identified using multiplex PCR. Virulence gene transcription was measured through reverse-transcriptase real-time PCR after infection of the vaginal cell line A431. The most common antibiotic resistance genes among the CVEC strains were aac(3)II, TEM, dfrA1, sul1, and qnrA. The predominant phylogroup was B2. The genes most frequently transcribed in these strains were fimH, papC, irp2, iroN, kpsMTII, cnf1, and ompT, mainly in CVEC strains isolated from chronic and occasional vaginal infections. The strains showed a large diversity of transcription of the virulence genes phenotype and antibiotic resistance genotype, especially in the strains of phylogroups, B2, A, and D. The strains formed 2 large clusters, which contained several subclusters. The genetic diversity of CVEC strains was high. These strains have a large number of transcription patterns of virulence genes, and one-third of them carry three to seven antibiotic resistance genes.

Prevalence of Escherichia coli K1 Rectovaginal Colonization Among Pregnant Women in Iran: Virulence Factors and Antibiotic Resistance Properties

Neonatal invasive infections caused by Escherichia coli K1 are still major health problems and effective preventive strategies at the maternal level can be a concern. The aim of this study was to determine the prevalence of rectovaginal colonization, related risk factors, virulence factors, and antibiotic resistance properties of E. coli K1 among pregnant women. In this cross-sectional study, vaginal and rectal swabs were collected from 400 pregnant women. The identification of E. coli isolates was performed by microbiological tests. A polymerase chain reaction (PCR) assay was used to identify the E. coli K1 strains. The antimicrobial susceptibility patterns were determined by the Kirby-Bauer disk diffusion. Two duplex PCR assays were developed separately to detect genes encoding virulence determinants (fimH, hlyF, ibeA, and iucC) in the E. coli strains. The vaginal and rectal maternal E. coli K1 colonization rates were 3.7% and 19.25%, respectively. There is no significant association between demographic-obstetric factors and vaginal E. coli colonization in pregnant women. The most effective antibiotics against E. coli K1 strains were imipenem, gentamycin, ciprofloxacin, and ceftazidime. In our study, the E. coli K1 strains were significantly more likely to possess the fimH (90.9% vs. 60.7%) and iucC (90.9% vs. 53.6%) than the E. coli non-K1 strains. This study demonstrates that E. coli K1 seems to be more virulent than non-K1 strains. Our findings highlight the importance of screening pregnant women for vaginal colonization by E. coli K1 and of the appropriate antibiotic prophylaxis for the prevention of early-onset E. coli neonatal infection and comorbidity.

Colonisation with extended-spectrum β-lactamase-producing Enterobacteriaceae in pregnant/post-partum women: Systematic review and meta-analysis

OBJECTIVES

Maternal colonisation with extended-spectrum β-lactamase (ESBL)-producing micro-organisms can lead to transmission of such pathogens to neonates, resulting in considerable morbidity. The aim of this study was to determine the global prevalence of maternal colonisation with ESBL-producing Enterobacteriaceae (ESBL-E).

METHODS

A systematic review of PubMed, Embase, Scopus, Web of Science and ProQuest databases as well as the grey literature was performed. Studies reporting the prevalence of ESBL-E colonisation during pregnancy or postpartum period were included. Prevalence data were grouped by geographic region. The pooled prevalence and 95% confidence interval (CI) was estimated by meta-analysis using a random-effects model.

RESULTS

Nineteen studies with reports from 16 countries (seven studies from Africa, one study from South America, two studies from Asia and nine studies from Europe) reporting data for 7352 pregnant/postpartum women were included. The pooled prevalence of ESBL-E colonisation was 8% (95% CI 5-10%). Prevalence estimates were 15% (95% CI 5-24%) in Africa, 6% (95% CI 4-10%) in South America, 5% (95% CI 4-6%) in Asia and 4% (95% CI 2-5%) in Europe. The pooled prevalence was higher in studies with low risk of bias (10%; 95% CI 7-13%) compared with those with high risk of bias (3%; 95% CI 2-3%).

CONCLUSION

There was heterogeneity regarding ESBL-E colonisation rates in different continents. The pooled prevalence rate was higher in Africa compared with other areas. Given that the highest rate was observed in Africa, implementing screening efforts for ESBL-E colonisation during pregnancy may be justified.

O-serogroups of multi-drug resistant cervicovaginal Escherichia coli harboring a battery of virulence genes

Multi-drug resistant cervicovaginal Escherichia coli (CVEC) infections are a serious health problem. The aim of this study is to determine the patterns of virulence genes, antibiotic resistance and O-serogroups of CVEC isolated in Mexico. Two hundred strains of CVEC were isolated from women attending two Clinics at the Instituto Mexicano del Seguro Social. E. coli O-serogroups and virulence markers were identified by PCR. Antibiotic susceptibility was determined using the Kirby-Bauer disc-diffusion method. Serogroups O25 (50%), O75 (9%) and O15 (7.5%) were the most frequent among the CVEC strains isolated. The frequencies for antibiotic resistance were ampicillin 97%, (n = 194); carbenicillin 93.5%, (n = 187); cefalotin 77%, (n = 154); and nitrofurantoin 71%, (n = 142). The frequency of multiresistant isolates (3-12 drugs) was 197 (98.5%). The most frequent virulence genes found were feoB (91.5%), fimH (89.5%), kpsMT11 (75%), iutA (66%), and iroN (59%). One hundred and four distinct patterns of virulence markers with antibiotic-resistance genes associated with O-serogroups were identified amongst CVEC isolates. In conclusion: most CVEC strains isolated were multiresistant to antibiotics, belonged to three O-serogroups, and possessed a battery of virulence factors. This knowledge may lead to improved guidelines and standards for treating cervicovaginal infections.

Detection of pap, sfa, afa, foc, and fim Adhesin-Encoding Operons in Uropathogenic Escherichia coli Isolates Collected From Patients With Urinary Tract Infection

Background:

Uropathogenic Escherichia coli (UPEC) with its virulence factors is the most prevalent cause of urinary tract infection (UTI).

Objectives;

This study aimed to determine the occurrence of fim, pap, sfa, and afa genes among 100 UPEC isolates collected from patients diagnosed with UTI.

Materials and Methods

A total of 100 UPEC isolates were obtained from urine samples of patients with UTI. The prevalence of 5 virulence genes encoding type 1 fimbriae (fimH), pili associated with pyelonephritis (pap), S and F1C fimbriae (sfa and foc) and afimbrial adhesins (afa) were determined through PCR method. We also investigated the phylogenetic background of all isolates. In addition, the distribution of adhesin-encoding operons between the phylogroups was assessed.

Results:

The prevalence of genes encoding for fimbrial adhesive systems was 95% for fim, 57% for pap, 16% for foc, and 81% for sfa. The operons encoding for afa afimbrial adhesins were identified in 12% of isolates. The various combinations of detected genes were designated as virulence patterns. The fim gene, which occurred in strains from all phylogenetic groups (A, B1, B2, and D) was evaluated and no significant differences were found among these groups. Conversely, significant differences were observed in relation to pap, afa, foc, and sfa operons.

Conclusions:

These results indicate that the PCR method is a powerful genotypic assay for the detection of adhesin-encoding operons. Thus, this assay can be recommended for clinical use to detect virulent urinary E. coli strains, as well as epidemiological studies.