Characterization of genotypes and antimicrobial resistance profiles of clinical isolates of Shigella from patients in the southern region of Iran.

BACKGROUND: Shigella spp., which are facultative anaerobic bacilli within the Enterobacteriaceae family, present a significant public health burden due to their role as prominent contributors to diarrheal diseases worldwide. A molecular analysis can facilitate the identification and assessment of outbreaks involving this bacterium. So, we aimed to investigate the antibiotic susceptibility pattern and clonal relatedness of clinical Shigella spp. isolates obtained from patients with diarrhea in Hormozgan province, South of Iran. METHODS: From 2019 to 2021, a cross-sectional investigation was conducted on 448 stool samples obtained from patients who were experiencing diarrhea, in the southern region of Iran. Shigella spp. isolates were identified based on biochemical and serological tests. All Shigella species were verified using species-specific polymerase chain reaction (PCR), followed by susceptibility testing to antimicrobial agents. Subsequently, genotyping of all Shigella species was conducted using ERIC-PCR. RESULTS: Out of a total of 448 stool samples, the presence of Shigella was detected in 62 cases, accounting for a prevalence rate of 13.84%. Among the identified isolates, the majority were attributed to S. flexneri, representing 53.23% of the cases. This was followed by S. sonnei at 24.19% and S. boydii at 22.58%. Notably, no instances of S. dysenteriae were found. The highest prevalence of Shigella isolates was observed in infants and children under the age of five. A significant proportion of the identified isolates demonstrated resistance to various antibiotics. Specifically, high resistance rates were noted for ampicillin (90.78%), piperacillin-tazobactam (87.1%), cefixime (83.87%), trimethoprim-sulfamethoxazole (83.87%), cefotaxime (82.26%), and ceftriaxone (80.65%). In addition, a substantial number (87.1%) of the isolates exhibited a multidrug-resistant (MDR) phenotype. Using the ERIC-PCR method, a total of 11 clusters and 6 distinct single types were identified among all the Shigella isolates. CONCLUSION: A notable occurrence of antibiotic-resistant Shigella species has been noted, with multi-drug resistant (MDR) strains presenting an increasing challenge for treating shigellosis worldwide, and this includes Iran. Techniques such as ERIC-PCR are useful for assessing the genetic variation and connections between Shigella strains, which indirectly contributes to understanding antimicrobial resistance patterns. Further research is needed to explore the specific correlation between resistance genes and ERIC genotyping patterns in Shigella strains.

The Role of Bacterial and Fungal Human Respiratory Microbiota in COVID-19 Patients.

Recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of coronavirus disease 2019 (COVID-19), has led to a worldwide pandemic with millions of infected patients. Alteration in humans' microbiota was also reported in COVID-19 patients. The alteration in human microbiota may contribute to bacterial or viral infections and affect the immune system. Moreover, human's microbiota can be altered due to SARS-CoV-2 infection, and these microbiota changes can indicate the progression of COVID-19. While current studies focus on the gut microbiota, it seems necessary to pay attention to the lung microbiota in COVID-19. This study is aimed at reviewing respiratory microbiota dysbiosis among COVID-19 patients to encourage further studies on the field for assessment of SARS-CoV-2 and respiratory microbiota interaction.

Molecular identification and distribution of non-tuberculous mycobacteria isolated from clinical specimens by PCR-sequencing method in West of Iran.

BACKGROUND AND AIMS: Infections by non-tuberculous mycobacteria (NTM) has rapidly increased in recent years, due to high infection rates related to the populations at risk like immunocompromised individuals, patients predisposed by prior pulmonary. The aim of this study was to investigate the presence of NTM in clinical samples and genetic diversity using 16S rRNA and rpoB sequence analysis. METHODS: A cross-sectional study was conducted on 45 diverse isolates collected from sputum in 2 years 2014-2015 using standard decontamination procedure. All mycobacterial isolates were grown on LJ medium and also conventional tests for preliminary identification of mycobacteria rely on traits and then DNA extraction. PCR was performed, and sequencing of 16S rRNA and rpoB genes was applied for NTM strains identification. RESULTS: A total of 45 isolates collected, 37 samples (83%) were evaluated as NTM. All NTM strains using molecular methods by sequencing 16S rRNA and rpoB gene were identified, by this way 12 different species have been identified which sequencing of rpoB was able to identify all species. The major species obtained were Mycobacterium simiae (22%), M. fortuitum (19%), and M. abscessus (13%). CONCLUSIONS: The results of our study showed that the patients were infected by a wide range of atypical mycobacteria. It was concluded that 16S rRNA gene sequencing coupled with rpoB marker is a high discriminatory power in identification of NTM. The presence of various species in clinical samples in Iran emphasizes the use of molecular method like sequence analysis of genes is necessary for reliable identification.