Iranian Journal of Microbiology最新文献

Background and objectives: The differential diagnosis of acute febrile illness (AFI) is influenced by the regional distribution of prevalent diseases. Hence, in our hospital-based data analysis, we evaluated the AFI cases presented to our center to raise awareness among clinicians and microbiologists regarding the percentage positivity of the prevailing diseases in the context of AFI based on serology, in and around the city of Dehradun.

Materials and methods: A total of 38,869 suspected AFI patients were enrolled in the study, and their specimens were analysed for infectious etiologies, including dengue, malaria, enteric fever, and scrub typhus by antigen-antibody based detection methods.

Results: Data analysis conducted from September 2021 to December 2022 among patients with AFI revealed that enteric fever, dengue, scrub typhus, and malaria accounted for 12.65%, 7.37%, 1.44%, and 0.18% of cases, respectively.

Conclusion: Since enteric fever followed by dengue was found to be contributing the maximum, mass education regarding safe drinking water, hygiene, sanitation, and strengthening of vector control measures is the need of the hour.

Background and objectives: Antibiotic-resistant bacteria are a growing global health concern, particularly in developing regions. Sulfonamides, once widely used, now face increasing resistance. This study assessed the prevalence, resistance profiles, and virulences traites of sulfonamide-resistant strains in Sétif, Algeria (2021-2023).

Materials and methods: A total of 215 clinical isolates were collected from patients aged 1 day to 96 years (mean 42.7). Most were community-acquired (77.2%), with urinary tract infections predominating (49.3% in women, 32.1% in men). Identification and susceptibility testing followed standard microbiological and Kirby-Bauer methods. Virulence factors (biofilm, hemolysin, protease, lecithinase, and lipase) were examined. Molecular docking compared sulfamethoxazole and trimethoprim binding to their enzymatic targets.

Results: Escherichia coli was the most frequent isolate (47.9%), followed by Enterobacter spp. (11.6%). Biofilm formation was common (88.8%), with complete production in Klebsiella, Citrobacter, Providencia, and Acinetobacter. Hemolysis patterns were α (30.7%), β (27.9%), and none (41.4%). Enzymatic activity included protease (48.8%), lecithinase (22.8%), and lipase (9.8%). High resistance was observed to penicillins (87.9%), cephalosporins (63.7%), and fluoroquinolones (56.3%). Resistance was lower to imipenem (33.0%) and amikacin (14.4%). Docking showed weaker sulfamethoxazole binding to DHPS than trimethoprim to DHFR.

Conclusion: The high prevalence of multidrug-resistant bacteria, especially E. coli, combined with biofilm and enzyme production, underscores the urgent need for careful antibiotic stewardship in this region.

Background and objectives: Pseudomonas aeruginosa, an opportunistic Gram-negative bacterium, is ubiquitous and represents one of the most challenging multidrug-resistant pathogens today. This multicenter study aimed to evaluate antibiotic resistance patterns, detect the cepA antibiotic resistance gene, and identify virulence factor genes (exoA, algD, lasB, and plcH) in clinical isolates of P. aeruginosa.

Materials and methods: This experimental study analyzed 74 P. aeruginosa isolates obtained from clinical samples at Imam Sajad (Yasuj) and Namazi (Shiraz) hospitals, including 74 clinical isolates and one standard reference strain. Bacterial identification was performed using standard biochemical tests. Antibiotic susceptibility was assessed by the disk diffusion method according to CLSI 2018 guidelines. Genomic DNA was extracted by means of boiling method, and PCR assays were applied to detect exoA, cepA, plcH, lasB, and algD genes. Data were analyzed with chi-square tests, considering p<0.05 as statistically significant.

Results: Among 74 P. aeruginosa isolates, all carried the exoA gene, while algD, plcH, cepA, and lasB were detected in 95.6%, 94.6%, 93.2%, and 91.9% of isolates, respectively. High resistance was observed to aztreonam and ticarcillin, while cefiderocol showed the greatest sensitivity. A significant correlation was found between the cepA gene and antibiotic resistance (P = 0.03).

Conclusion: This study reveals a high prevalence of virulence genes and increasing antibiotic resistance among P. aeruginosa clinical isolates, highlighting the urgent need for effective therapeutic strategies to combat this pathogen.

Background and objectives: Olfactory dysfunction is common in COVID-19 patients, with a pooled prevalence of up to 50%. This study investigated the efficacy of pulsed and continuous ultrasound treatment on olfactory disorders of these patients.

Materials and methods: Three groups of COVID-19 patients having anosmia were studied, each including 15 patients. Pulsed ultrasound and continuous ultrasound were used to evaluate their efficacy on anosmia recovery in two groups of patients. The patients were subjected to pulsed or continuous ultrasound intervention 10 times during two weeks (5 days per week). The control group received no intervention. The SIT (Smell Identification Test) was used to assess the severity of olfactory dysfunctions of all patients on days 0 and 14. Data analysis was done using MANCOVA test.

Results: Totally 20 (44.4%) and 25 (55.6%) patients were affected by Delta and Omicron variants of COVID-19 virus. The SIT test results showed a significant improvement in olfactory recovery of all 30 patients except one after ultrasound treatment (p < 0.05), but this was not observed in the control group. Pulsed and continuous ultrasound treatment showed an almost equal effect on olfaction status.

Conclusion: Although there was no difference in olfactory test results in the control group during intervention period, pulsed and continuous ultrasound interventions were significantly effective in improving patients' olfaction. Pulsed and continuous therapeutic ultrasound improved the COVID-19 related olfactory dysfunction and can be considered as a promising technique for postinfectious olfaction.

Background and objectives: Human papillomavirus (HPV) causes about 4.5% of all new human cancers. The purpose of this study was to look into the prevalence of various HPV types in patients with lung cancer.

Materials and methods: The study included a cohort of 61 individuals who had received treatment at Imam Khomeini Hospital in Ahvaz between 2011 and 2019. Paraffin-embedded tissues were used for molecular analysis. The primary goal was to assess the differences in HPV prevalence between lung cancer patients and a control group, using a Nested PCR assay followed by sequencing.

Results: Among the lung cancer patients, HPV DNA was detected in 10 individuals, while three individuals in the control group were also positive (16.3% versus 12.0%, P=0.65). Notably, every detected HPV variant was classified as the high-risk type 16. Additionally, the researchers investigated potential associations between age, sex, smoking habits, and lung cancer in both HPV-positive and negative patients. The study findings revealed that age, sex, and smoking habits did not show statistically significant associations with the presence of HPV (P>0.05). Moreover, Lung cancer incidence was not significantly correlated with HPV infection (P>0.05).

Conclusion: Therefore, according to the study's findings, smoking, HPV infection, and lung cancer prevalence were not significantly correlated in the population under investigation.

Background and objectives: Helicobacter pylori (H. pylori), as a Gram-negative pathogen plays a key role in causing gastritis, peptic ulcer disease, and gastric malignancies. The bacterial adhesin HopQ binds human CEACAM1, promoting adherence and CagA oncoprotein translocation. This study aimed to establish a yeast-based surface expression platform to investigate the HopQ-CEACAM1 interaction as a basis for future inhibitor screening.

Materials and methods: The N-terminal domain of human CEACAM1 (C1ND) was displayed on the surface of Saccharomyces cerevisiae BY4741 as C1ND or C1ND-EGFP via Aga2 fusion. Constructs were introduced by electroporation and confirmed by PCR. Protein expression and localization were validated by western blot, confocal microscopy, and flow cytometry. Binding assays involved GFP-tagged HopQ and GFP-expressing H. pylori.

Results: Western blot confirmed surface expression of C1ND and C1ND-EGFP. Confocal microscopy and flow cytometry showed strong fluorescence signals, with significantly higher mean fluorescence intensity and anti-GFP-positive yeast compared to controls (P < 0.01). Yeast-displayed C1ND specifically bound HopQ-GFP and GFP-expressing H. pylori.

Conclusion: Yeast surface display of CEACAM1's N-domain is an effective model for studying HopQ-CEACAM1 binding and offers potential for identifying inhibitors to block H. pylori adhesion and associated disorders.

Background and objectives: The emergence of plasmid-mediated resistance to quinolones is a growing global threat that complicates the control of multidrug-resistance (MDR) in Enterobacteriaceae. This study was conducted to determine the frequency of the qepA gene and its association with antibiotic resistance in Citrobacter freundii isolates from various clinical samples.

Materials and methods: To conduct this study, a total of 27 C. freundii isolates collected from urine, endotracheal aspirates, sputum, blood, and stool samples were identified using standard biochemical tests and culture methods. Their susceptibility to ciprofloxacin was determined via the MIC agar dilution method. Specific primers were used to confirm C. freundii and detect the qepA gene by PCR. Subsequently, DNA sequencing was performed using a capillary method, and the sequences were compared to similar genes available in GenBank.

Results: Among the isolated C. freundii strains, 77.78% were resistant to ciprofloxacin. Of these resistant isolates, 9.52% were found to harbor the qepA gene. Sequencing and BLAST analysis confirmed a 99% similarity to the Citrobacter koseri strain CD4359 plasmid pCD4359 (GenBank accession number KR259132.1) and revealed a point mutation at position 58.

Conclusion: This finding highlights the distribution of the qepA gene in clinical isolates, emphasizing the need for continuous molecular surveillance to screen PMQR determinants and to implement effective antimicrobial stewardship strategies.

Background and objectives: Coronavirus disease 2019 (COVID-19), due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has expanded rapidly to all over the world. Interleukin-17 is one of the inflammatory cytokines which is highly expressed in the blood of individuals with COVID-19. Our aim in the present survey was to assess the mRNA expression levels of cytokine IL-17A, IL-17F and TNF-α in the blood of COVID-19 patients compared with healthy control individuals.

Materials and methods: A total of 69 patients including 32 mild patients, 20 severe and 17 asymptomatic patients in comparison with 25 healthy controls were evaluated. To measure the expression profile of IL-17A and IL-17F in whole blood, quantitative PCR was used.

Results: Asymptomatic, mild, and severe SARS-CoV-2 infections were found to have significantly higher levels of IL-17A and IL-17F mRNAs than the healthy group (fold change IL-17A: 3.778; p= 0.002, 4.003; p= 0.001, 2.608; p= 0.0001 respectively, fold change IL-17F: 2.967; p= 0.003, 3.819; p= 0.001, 2.617; p= 0.0012 respectively). TNF-α mRNA expression was also measured, which shows an approximately similar increase compared to IL-17 (fold change: 2.726; p= 0.002, 2.383; P= 0.001, 2.631; p= 0.001, respectively).

Conclusion: SARS-CoV-2 infection severity was associated with blood levels of IL-17A and IL-17F mRNA.

Background and objectives: Actinobacteria are ubiquitous across diverse environmental niches. Brevibacterium strains within this phylum are widely distributed in both marine and terrestrial ecosystems worldwide. Marine environments are defined by distinct physicochemical properties-high salinity, alkaline pH, fluctuating O levels, and dynamic nutrient availability-which set them apart from terrestrial habitats. The broad ecological range of Brevibacterium strains raises questions about genome-encoded metabolic features that have evolved to adapt in marine environments.

Materials and methods: Genomics of Brevibacterium strains from various marine provinces was analyzed, focusing on core genome and pan-genome structure.

Results: Core genome and pan-genome derived phylograms reveal a distinct polyphyletic origin of marine strains, as evidenced by their phylogenetic proximity despite diverse species affiliations. Only 1.16% of gene clusters from the total nonredundant gene repertoire were part of the core genome. Core genome size is shaped by geographical distribution. Notably, when strains from localized regions are analyzed, the core genome expands, indicating specialized functional requirements of additional genes within that environment. In marine isolates, the core genome includes genes involved in nutrient uptake, osmoregulation, and resistance to sediment genotoxicity. Additionally, a marine province-specific core genome analysis reveals genomic adaptations essential for acclimatization across different environments, regardless of species-level taxonomy.

Conclusion: Microbial genome evolution is shaped by ecological niche differentiation. The emergence and spread of habitats driven by tectonic plate movements may contribute to province-specific genomic divergence in Brevibacterium. This hypothesis merits further investigation, particularly as genomic data from deeper, geologically stable environments such as marine sediments become more accessible.

Background and objectives: The presence of the BK virus in wastewater indicates pollution, as it is shed in the urine of infected individuals. Over fifty percent of the human population remains asymptomatic for the BK virus. Reactivation of the BK virus in immunosuppressed individuals can lead to serious health issues, including cystic hemorrhagic, nephritis, and kidney graft rejection. The BK virus is associated with various cancers, such as head and neck, prostate, bladder, and colorectal cancers. The urban wastewater inlets into the Karun River cause the river contamination. This study focused on detecting the BK virus in wastewater inlet in Karun River, Ahvaz city, Iran.

Materials and methods: Sixty raw wastewater samples were collected from diverse urban sources and concentrated using polyethylene glycol 6000 to isolate BK virus. The BK virus isolates were analyzed for genotypes and the non-coding control region (NCCR).

Results: The Nested PCR results indicated that thirty-two out of sixty samples (53.33%) were positive for the BK virus. The phylogenetic analysis revealed the dominance of BK virus genotype Ib2, followed by genotype 4. The BK virus non-coding control region (NCCR) analysis identified an archetype strain.

Conclusion: The sewage plant treatment should be implemented to remove pathogenic viruses specially BK virus and to curb the circulating of BK virus in human and environment.