European Journal of Microbiology & Immunology最新文献

Glyphosate, the active compound of Roundup, is one of the most used pesticides in the world. Its residues are often detected in animal feed, but the impact on the animal gut microbiota and on pathogens of the intestine has not intensively been investigated. In this study, we analyzed the minimum inhibitory concentration (MIC) of glyphosate isopropylamine salt and a common glyphosate-containing herbicide formulation in 225 Salmonella enterica isolates by broth microdilution. A bacteriostatic effect of glyphosate on Salmonella growth was detected at the concentration range of 10 to 80 mg/mL for both the active ingredient and the ready-to-use formulation. Time/year of isolation, host species, and serovars revealed a statistically significant influence on MIC values. Recently collected Salmonella isolates had significantly higher MIC values for glyphosate and the glyphosate-containing product compared with isolates collected between 1981 and 1990. Isolates from pigs showed significantly higher MIC values compared with isolates from poultry, and isolates of the Salmonella serovar Typhimurium had significantly higher MIC values than Salmonella Enteritidis and Infantis isolates.

Trichomoniasis, a common curable sexually transmitted infection caused by the protozoan Trichomonas vaginalis (TV), is usually asymptomatic. However, symptomatic women may experience vaginal discharge and/or vulvar irritation. This study evaluated cobas^® TV/ Mycoplasma genitalium (MG) (Conformité Européene marking for in vitro diagnostic medical devices [CE-IVD]) against other nucleic acid amplification tests (NAATs) for detecting TV in female urogenital specimens. Matched de-identified specimens from 412 females were collected. cobas^® TV/MG results were compared against a composite reference (CR) of 3 different NAATs for TV (Aptima TV, modified S-DiaMGTV™, and a laboratory-developed test). The overall TV prevalence rate was 6.2%, based on cobas^® TV/MG results. Relative to the CR, cobas^® TV/MG sensitivity/specificity for the specimen types were endocervical swabs (ES) 100%/99.2%, vaginal swabs (VS) 100%/99.7%, urine (U) 100%/99.7%, and cervical specimens in PreservCyt^® solution (PC) 100%/99.5%. There was no significant statistical difference between clinician-collected and self-collected VS (p = 0.28). Correlation of cobas^® TV/MG vs. Aptima TV demonstrated the following positive, negative, and overall percent agreements, respectively: ES 69.0%, 98.7%, and 96.6%; VS 88.9%, 99.5%, and 98.8%; U 100%, 100%, and 100%; and PC 95.5%, 99.0%, and 98.8%. Detection of TV with cobas^® TV/MG for use on the cobas^® 6800/8800 systems demonstrated excellent performance in female urogenital specimens (overall sensitivity/specificity of 100%≥99.2%).

Our research group has recently shown that Borrelia burgdorferi, the Lyme disease bacterium, is capable of forming biofilms in Borrelia-infected human skin lesions called Borrelia lymphocytoma (BL). Biofilm structures often contain multiple organisms in a symbiotic relationship, with the goal of providing shelter from environmental stressors such as antimicrobial agents. Because multiple co-infections are common in Lyme disease, the main questions of this study were whether BL tissues contained other pathogenic species and/or whether there is any co-existence with Borrelia biofilms. Recent reports suggested Chlamydia-like organisms in ticks and Borrelia-infected human skin tissues; therefore, Chlamydia-specific polymerase chain reaction (PCR) analyses were performed in Borrelia-positive BL tissues. Analyses of the sequence of the positive PCR bands revealed that Chlamydia spp. DNAs are indeed present in these tissues, and their sequences have the best identity match to Chlamydophila pneumoniae and Chlamydia trachomatis. Fluorescent immunohistochemical and in situ hybridization methods demonstrated the presence of Chlamydia antigen and DNA in 84% of Borrelia biofilms. Confocal microscopy revealed that Chlamydia locates in the center of Borrelia biofilms, and together, they form a well-organized mixed pathogenic structure. In summary, our study is the first to show Borrelia-Chlamydia mixed biofilms in infected human skin tissues, which raises the questions of whether these human pathogens have developed a symbiotic relationship for their mutual survival.

Salmonella is a major cause of morbidity and mortality in humans worldwide, and the infection with multidrug-resistant strains can cause severe diseases. This study was designed to evaluate the antimicrobial resistance, to detect the virulence genes, and to study the genetic diversity of isolated Salmonella strains using 16S rRNA sequences. For this, 34 Salmonella strains isolated from sausages were identified using biochemical and serological methods. Molecular tools were used to evaluate the presence of virulence genes (orgA, sitC, sipB, spiA, iroN, and sifA) using simplex and multiplex polymerase chain reaction (PCR) and to sequence 16S rRNA genes for phylogenetic analysis. The susceptibility to 24 selected antibiotics was also studied. The results of this study showed that all isolated Salmonella were positive for targeted virulence genes and were resistant to at least one antibiotic. However, the multidrug resistance was observed in 44% of isolated strains. The phylogenetic analysis of 16S rRNA sequences highlighted that Salmonella isolates were divided into 3 clusters and 3 sub-clusters, with a ≥98% similarity to Salmonella enterica species. From this study, we conclude that sausages are considered as a potential source of Salmonella, which could be a major risk to public health.

Intestinal carriage of multi-drug resistant (MDR) Gram-negative bacteria including Pseudomonas aeruginosa (Psae) constitutes a pivotal prerequisite for subsequent fatal endogenous infections in patients at risk. We here addressed whether fecal microbiota transplantation (FMT) could effectively combat MDR-Psae carriage. Therefore, secondary abiotic mice were challenged with MDR-Psae by gavage. One week later, mice were subjected to peroral FMT from either murine or human donors on 3 consecutive days. Irrespective of murine or human origin of fecal transplant, intestinal MDR-Psae loads decreased as early as 24 h after the initial FMT. Remarkably, the murine FMT could lower intestinal MDR-Psae burdens by approximately 4 log orders of magnitude within 1 week. In another intervention study, mice harboring a human gut microbiota were perorally challenged with MDR-Psae and subjected to murine FMT on 3 consecutive days, 1 week later. Strikingly, within 5 days, murine FMT resulted in lower loads and carrier rates of MDR-Psae in mice with a human gut microbiota. In conclusion, FMT might be a promising antibiotics-independent option to combat intestinal MDR-Psae carriage and thus prevent from future endogenous infections of patients at risk.

Background: Carbapenem-resistance is frequently detected in Enterobacteriaceae isolated from patients in Tunisia. The study was performed to identify frequent carbapenemases in Tunisian isolates.

Methods: Between May 2014 and January 2018, 197 ertapenem-resistant Enterobacteriaceae were isolated at the microbiological department of the Military Hospital of Tunis. The strains were phenotypically characterized and then subjected to in-house polymerase chain reaction (PCR) targeting the carbapenemase genes bla_IMP, bla_VIM, bla_NDM, bla_SPM, bla_AIM, bla_DIM,bla_GIM, bla_SIM, bla_KPC, bla_BIC , and bla_OXA-48.

Results: The assessed 197 ertapenem-resistant Enterobacteriaceae from Tunis comprised 170 Klebsiella pneumoniae, 19 Enterobacter cloacae, 6 Escherichia coli, 1 Citrobacter sedlakii, and 1 Enterobacter asburiae. Thereby, 55 out of 197 isolates (27.9%) were from blood cultures, suggesting a systemic disease. The carbapenemase gene bla_OXA-48 quantitatively dominated by far with 153 detections, followed by bla_NDM with 14 detections, which were distributed about the whole study interval. In contrast, bla_BIC and bla_VIM were only infrequently identified in 5 and 3 cases, respectively, while the other carbapenamases were not observed.

Conclusions: The carbapenemase gene bla_OXA-48 was identified in the vast majority of ertapenem-resistant Tunisian Enterobacteriaceae while all other assessed carbapenemases were much less abundant. In a quantitatively relevant minority of isolates, the applied PCR-based screening approach did not identify any carbapenemases.

Nowadays, multidrug-resistant bacteria are considered as an increasing serious threat to public health worldwide. Global and local surveillance data are helpful in the application of the most efficient antimicrobial agent in bacterial infections. In the current study, we aimed to analyze the activity of the previously cleared agent ceftolozane/ tazobactam (C/T) in African and European multidrug-resistant Gram-negative bacteria. Susceptibility testing was performed on 147 extended-spectrum β-lactamase (107 Escherichia coli and 40 Klebsiella pneumoniae) and 103 carbapenemase-producing Gram-negative bacteria using Etest according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints. Among the extended-spectrum β-lactamase producing isolates, 91 Escherichia coli isolates (85%) and 23 Klebsiella pneumoniae isolates (57.5%) were susceptible towards C/T whereas out of the 103 carbapenemase-producing isolates 102 (99.0%) were C/T-resistant. C/T should be included in susceptibility testing to fairly administer this antimicrobial agent in infections caused by multidrug-resistant bacteria. It may be considered as a therapy option for infections caused by extended-spectrum β-lactamase-producing bacteria once susceptibility to this antimicrobial combination has been confirmed.

Setting: A survey of the prevalence of drug-resistant tuberculosis (DR-TB) in new and previously treated patients (PTPs) was performed in Burkina Faso from 2016 to 2017.

Design: In this cross-sectional survey, a structured questionnaire was administered to eligible smear-positive patients in all 86 diagnostic and treatment centers of the country to collect their socio-demographic characteristics and medical histories. Their sputa were tested using the Mycobacterium tuberculosis/rifampicin (MTB/RIF) Xpert assay. Those which were found to be positive for TB and rifampicin-resistant were also tested with GenoType MTBDRplus2.0 and MTBDRsl2.0. Univariate and multivariate logistic regressions were performed to determine risk factors associated with rifampicin resistance.

Results: Of the 1140 smear-positive patients enrolled, 995 new and 145 PTPs were positive for MTB complex by Xpert. Of these, 2.0% (20/995, 95% confidence interval (CI): 1.1-2.9) of the new cases and 14.5% (95% CI: 14.2-20.2) of the PTPs were resistant to rifampicin; 83% of them has multidrug-resistant tuberculosis (MDR-TB). None were pre-extensively drug-resistant TB (pre-XDR-TB) or XDR-TB. Only the previous treatment was significantly associated with rifampicin resistance, p < 0.0001.

Conclusion: Similar to global trends, rifampicin resistance was significantly higher in patients with prior TB treatment (14.5%) than in naïve patients (2.0%). These percentages are slightly below the global averages, but nonetheless suggest the need for continued vigilance. Extending the use of Xpert testing should strengthen the surveillance of DR-TB in Burkina Faso.

Purpose: We aimed to determine the association between Chlamydia trachomatis infection and female sex work, and the association between sociodemographic, obstetric, and behavioral characteristics of female sex workers and C. trachomatis infection.

Methods: Through a case-control study design, we studied 201 female sex workers and 201 age-matched women without sex work in Durango City, Mexico. C. trachomatis DNA was detected in cervical swab samples using polymerase chain reaction.

Results: C. trachomatis DNA was detected in 32 (15.9%) of the 201 cases and in 6 (3.0%) of the 201 controls (odds ratio [OR] = 6.15; 95% confidence interval [CI]: 2.5-15.0; P < 0.001). The frequency of infection with C. trachomatis in female sex workers did not vary (P > 0.05) regardless of the history of pregnancies, deliveries, cesarean sections, or miscarriages. Regression analysis of the behavioral characteristics showed that infection with C. trachomatis was associated only with consumption of alcohol (OR = 2.39; 95% CI: 1.0-5.71; P = 0.04). Conclusions: We conclude that C. trachomatis infection is associated with female sex work in Durango City, Mexico. This is the first age-matched case-control study on the prevalence of C. trachomatis infection in female sex workers in Mexico using detection of C. trachomatis DNA in cervical samples.

A subgroup of oropharyngeal squamous cell carcinomas (OSCCs) are causally linked to infection with high-risk human papillomaviruses (HR-HPVs). To evaluate the prevalence of simultaneous oral HPV infection in females with cervical high-grade squamous intraepithelial lesions (HSIL), tonsillar- and cervical smears were collected simultaneously from 73 patients and analyzed for HPV using two commercial assays, PapilloCheck (Greiner-Bio-One) and Linear Array (Roche). Only 3/73 (4.1%) tonsillar smears were HPV positive (HPV+), with HPV types 16, 35, and 45, respectively, detected by both assays (100% agreement). Concordant results were also found in 60/66 (91%) evaluable cervical smears. Of specimens, positive by both assays, typing results completely coincide in 71% (all types are identical) and partially coincide in 27% (at least one type is identical). Taken together, results of HPV detection and typing by PapilloCheck and Linear Array are highly congruent and confirm the low prevalence of HR-HPV in tonsillar smears of patients with HSIL of the uterine cervix. Our data indicate low prevalence of oropharyngeal HPV infection in patients with high-grade cervical dysplasia. The low detection rate was confirmed by using two different commercial assays with largely consistent results of HPV detection and typing, but with some variation for particular HPV types. Comparative testing of larger numbers is required to identify the HPV types prone to escape detection with particular assays.