Jundishapur Journal of Microbiology
Volume:15 Issue: 5, May 2022

Commensal extended-spectrum β-lactamase (ESBL) producing Escherichia coli isolates in the gut can be the reservoir of virulence factors and resistance genes.

We investigated the molecular feature, risk factors, and quinolone/fluoroquinolone (Q/FQ) resistance in sequence type 131 (ST131) and non-ST131: ESBL-producing E. coli (EPE) isolates in healthy fecal carriers.

A total of 540 fecal samples and its demographic data were collected from healthy adults in Tehran in 2018. ST131 isolates were identified by multilocus sequence typing (MLST) analysis, and the characteristics of the virulence factor, phylogenic assay, and Q/FQ resistance genes in ST131 and non-ST131 were determined by polymerase chain reaction (PCR).

The EPE isolates mainly belonged to the commensal phylogenetic groups A (54.9%) and D (18.1%). The type 1 fimbriae (fimH; 89.6%) gene was the predominant virulence factor, and there was a significant correlation between ferric yersiniabactin uptake (fyuA; 52.9%), aerobactin receptor (iutA; 17.6%), and group II capsule synthesis (kpsMII; 35.3%) with ST131. In Q/FQ-resistant isolates, qnrS (19%) was the predominant gene, and mutations mostly occurred at codon S83 in GyrA The number of mutations in gyrA and parC genes was significantly higher in ST131 isolates than in non-ST131 isolates. There was a significant positive correlation between diabetes, male gender, and living in the south of the city with EPE carriage (P < 0.05).

Accumulation of multiple virulence factors and high- level resistance to Q/FQ in some phylogroups (B2 and D), particularly ST131 isolates, require to be considered in detecting resistant isolates in healthy carriers. According to the risk factor for spreading of EPE isolates (diabetes, living in low-income parts of the city, and male gender), the necessary strategies are required to be developed to control the dissemination of antimicrobial-resistant isolates in the community.

Quinolone resistant Salmonella serotypes have been reported in recent years and have become increasingly widespread worldwide.

We evaluated the molecular mechanism of quinolone resistance in non-typhoidal Salmonella strains isolated from clinical samples in Tehran, Iran.

The present study included the Salmonella isolates originated from hospitalized individuals and outpatients in Tehran, Iran. Serotyping of nalidixic acid-resistant Salmonella isolates was done by slide agglutination method. Then, the quinolone resistance-determining region (QRDR) of topoisomerase gene gyrA and the plasmid-mediated quinolone resistance (PMQR) determinants were detected using the polymerase chain reaction (PCR) method. Restriction fragment length polymorphism (RFLP) analysis was also employed to determine the possible mutation in the gyrA gene of those strains. Mutant strains were detected by enzymatic digestion, and their PCR products were sequenced immediately.

Amongst 141 isolates, 60% showed nalidixic acid resistance, whereas none of them were ciprofloxacin-resistant. The commonly prevalent serotypes were S. Enteritidis and S. Infantis. Of 85 nalidixic acid-resistant strains, 17 (20%) isolates harbored the qnrS gene. However, PCR analysis of the quinolone-resistant strains did not detect qnrA and qnrB genes. PCR-RFLP and sequencing analysis of the QRDRs of the gyrA gene indicated that 16 (18.8%) isolates had mutant patterns, and the most common point mutation was serine to phenylalanine at position 83.

Our results demonstrated that point mutations in gyrA and the existence of plasmid-mediated gene qnrS were important mechanisms of quinolone resistance in non-typhoidal Salmonella strains isolated from human origin. Other alternative mechanisms of resistance, such as alterations in the expression of efflux pumps, should be studied to provide greater insight into the molecular mechanism of quinolone-resistant non-typhoidal Salmonella isolates.

Helicobacter pylori colonizes gastric tissue in obese patients and mostly remains undetected clinically, as histological and molecular analysis is seldom ordered in such cases.

This study aimed to detect the frequency of H. pylori using different techniques in sleeve gastrectomy specimens of obese patients with minimal or no symptoms suggestive of gastritis.

This longitudinal study was carried out at Farooq Hospital Westwood Lahore, Morbid Anatomy and Histopathology Department and Resource Laboratory at the University of Health Sciences, Lahore, Pakistan, from February 2021 to September 2021. This study selected 80 cases who underwent sleeve gastrectomy within six months. Helicobacter pylori was detected by rapid urease test (RUT), modified Giemsa staining, and polymerase chain reaction (PCR) techniques.

Most patients (83.7%) were clinically asymptomatic, while 10% had mild and 6.3% had moderate to severe gastritis symptoms. Of the asymptomatic patients, 56.7% of biopsies showed chronic gastritis. Rapid urease test and modified Giemsa staining showed positive evidence for H. pylori in 47.3% of cases, whereas an additional 13.2% of biopsies that were negative on conventional methods showed the amplification of H. pylori DNA by PCR. Patients were discharged with proton-pump inhibitors therapy (40 mg/day) that showed no adverse post-surgical event over a follow-up of six months.

Persistent obesity and other socioeconomic factors may lead to colonizing asymptomatic H. pylori infection. More sensitive techniques for detecting H. pylori may be employed in resource-constrained settings for better patient outcomes and to minimize the complications after sleeve gastrectomy.

Urinary tract infections represent a major expensive, common public health problem worldwide due to their high prevalence and the difficulties associated with their management.

This study aimed to characterize the Enterobacter cloacae strains isolated from urinary tract infections in the medical diagnostic laboratories of Shahrekord, Iran.

Urine samples from patients with urinary tract infections from the Shahrekord medical diagnostic laboratories located in Chaharmahal and Bakhtiari Province, Iran, were collected from June 2019 to February 2020. When the samples were cultured, the different isolates of E. cloacae were identified by biochemical tests. Biofilm production capacity was evaluated. Bacterial susceptibility to antibiotics was determined using the Kirby Bauer method, and antibiotic resistance genes were researched by the multiplex PCR technique.

In this study, 65 isolates of E. cloacae were obtained. The highest percentage of resistance was observed for co-trimoxazole (84.62%), ampicillin (76.93%), tetracycline (73.85%), and above half of the E. cloacae strain isolates (53,85%) were strongly involved in biofilm production. Some genes, including qnr A, qnr B, qnr S, tetA, tet B, sul1, bla CTXM, bla SHV, and(2)la, ant(3)la, and aac(3)IIa, were detected in the genome of these isolates.

The strains are multi-resistant, and their resistance has already reached the carbapenem class. This requires further investigation, and urgent measures must be adopted.

Clostridium spp. spores are resistant to many factors, including alcohol-based disinfectants. The presence of clostridial spores in a hospital environment may lead to infection outbreaks among patients and health care workers.

This study is aimed to detect clostridial spores in the aurology hospital using C diff Banana Broth™ and assess the antibiotic sensitivity and toxinotypes of isolates.

After diagnosing COVID-19 in medical staff and closing an 86-bed urology hospital in 2020 for H2O2 fogging, 58 swabs from the hospital environment were inoculated to C diff Banana Broth™, incubated at 37°C for 14 days, checked daily, and positive broths were sub-cultured anaerobically for 48 h at 37°C. After identification, multiplex PCR (mPCR) was performed for Clostridium perfringens, C. difficile toxin genes, and minimum inhibitory concentration (MIC) determination.

In this study, 16 out of 58 (~ 28%) strains of Clostridium spp. were cultured: 11 - C. perfringens, 2 - C. baratii, and 1 each of C. paraputrificum, C. difficile, and C. clostridioforme. 11 C. perfringens were positive for the cpa, 7 - the cpb2, 2 – cpiA, and 1 – cpb toxin genes. All isolates were sensitive to metronidazole, vancomycin, moxifloxacin, penicillin/tazobactam, and rifampicin. Two out of the 11 C. perfringens strains were resistant to erythromycin and clindamycin.

Regardless of the performed H2O2 fogging, antibiotic-resistant, toxigenic strains of C. perfringens (69%) obtained from the urology hospital environment were cultured using C diff Banana Broth™, indicating the need to develop the necessary sanitary and epidemiological procedures in this hospital.

One of the most prevalent infections in hospitalized patients is candiduria. As the prevalence of this infection is increasing, new epidemiologic and therapeutic data can be used as a guide for the management of patients.

This research aimed to determine the epidemiological and antifungal susceptibility profile of candiduria.

A total of 104 patients admitted to the nephrology and ICU wards of Bu Ali and Labbafinezhad hospitals in Tehran, Iran, were studied in this cross-sectional investigation. Urine samples were examined using direct smear, culture, and PCR-sequencing techniques. The culture plates were subjected to colony count. The clinical and laboratory standards institute (CLSI) document M27 4th ed was used to assess susceptibility to amphotericin B, itraconazole, caspofungin, and fluconazole.

Out of 104 patients, 26 (25%) were diagnosed with candiduria. Most patients were between the ages of 64 - 79 years (n = 9, 34.61%) and female (n = 17, 23.94%). Stroke and urinary catheterization were the most common underlying diseases. Candida glabrata (n = 10, 38.64%) was the most common cause of candiduria. Caspofungin and amphotericin B were the most effective antifungal medicines.

Candida glabrata has been identified as the most common cause of candiduria. Due to the increasing antifungal resistance in this species, proper treatment of patients is a crucial concern. Caspofungin exhibited potent antifungal activity against all tested isolates. Still, regardless of its favorable in vitro activity, due to its poor glomerular filtration or tubular secretion in vivo, it has sub-therapeutic antifungal concentrations in the urine.