Jundishapur Journal of Microbiology
Volume:17 Issue: 10, Oct 2024

Clinical studies have shown that variations in the ACE2 gene can influence susceptibility to and the severity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections. Although the evidence is not conclusive, recent studies have suggested a potential link between the ACE2 rs2285666 polymorphism and COVID-19.

This multicentric clinical study, conducted in Lorestan and Golestan provinces, aimed to examine the association between the ACE2 rs2285666 polymorphism and COVID-19 in Iranians of various ethnicities, including Fars, Lur, Turkmen, and Balooch.

A total of 372 participants were evaluated, with 201 testing positive for SARS-CoV-2 and 171 negative. The PCR-based restriction fragment length polymorphism (PCR-RFLP) technique, using the AluI enzyme, was employed to identify the polymorphism. Demographic and clinical data were analyzed using IBM SPSS. Hazards were assessed through odds ratio analysis, while Hardy-Weinberg equilibrium (HWE) and genotype variations were evaluated using SNPSTATS.

PCR-RFLP analysis indicated that the AA genotype may increase susceptibility to COVID-19. Among female COVID-19-positive patients, 56%, 29%, and 15% exhibited GG, GA, and AA genotypes, respectively, compared to 61%, 35%, and 4% in the control group. In male individuals, the frequencies of G and A genotypes were 89% and 11% in the healthy group, while they were 25% and 75%, respectively, in the patient group. Polymorphism frequencies were not in HWE in both the positive and negative groups (P < 0.05). Logistic regression analysis showed that the AA genotype differed in co-dominant and recessive inheritance models, with odds ratios (OR) of OR = 4.06 (1.10 - 15.00) and OR = 4.21 (1.16 - 15.24). The ACE2 rs2285666 AA or A genotype was strongly associated with an increased risk of COVID-19 in this study.

A significant difference in the distribution of the AA and A genotypes was observed in COVID-19 patients. Further studies involving larger and more diverse populations are necessary to explore the impact of this polymorphism on the susceptibility to and severity of COVID-19.

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has become a major global concern. Quorum sensing (QS) regulates the expression of biofilm formation genes and virulence factors. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) is widely used in epidemiological molecular studies.

The purpose of the present study was to determine the QS characteristics and genetic relatedness of CRPA.

A total of 57 non-duplicative CRPA isolates were collected. A microtiter plate assay was used to assess biofilm formation. After DNA extraction, PCR was performed to detect resistance elements and QS-encoded genes. Enterobacterial repetitive intergenic ERIC-PCR was conducted using specific primers.

The biofilm formation assay revealed that 10.5%, 19.3%, and 70.2% of isolates formed weak, moderate, and strong biofilms, respectively. Of the isolates, 75.4%, 64.9%, 12.3%, and 8.7% carried the bla IMP , bla VIM , bla NDM , and bla KPC genes, respectively. Additionally, 73.7%, 7.0%, and 1.7% of CRPA isolates carried the bla OXA-48-like , bla OXA-23-like , and bla OXA-20/40-like genes, respectively. The prevalence of the lasR , lasI , rhlI , rhlR , aprR , aprA , and rhlAB genes were 100%, 96.5%, 92.9%, 89.5%, 84.2%, 73.6%, and 63.2%, respectively. Enterobacterial repetitive intergenic ERIC-PCR revealed eight distinct clusters (A, B, C, D, E, F, G, and H) using a similarity cut-off of ≥ 60%.

The findings indicate a high prevalence of strong biofilm formation and quorum-sensing genes among CRPA isolates. The study highlights the importance of biofilm production and genetic diversity in CRPA isolates, underscoring the challenges in infection control and treatment strategies.

Human papillomavirus (HPV) is the most prevalent sexually transmitted infection, especially among sexually active individuals.

This study aimed to determine the prevalence of HPV infection among males and females in Southern Iran. Although previous studies have explored HPV prevalence in various provinces across Iran, this research is unique as the first to examine a four-type sample within this region.

This cross-sectional study involved a sample of residents from Southern Iran, comprising 82 females (71.9%) and 32 males (28.1%), aged between 13 and 74 years, most of whom were sexually active. The main focus of the research was to investigate HPV infection across various anatomical sites in both healthy women and those with external genital warts (eGW).

The anatomical sites assessed included the oral, anal, vaginal, and urinary areas. Out of the total sample, 79 individuals (69.3%) tested positive for HPV. Within this group, 65 individuals (81.3%) were from the eGW group, while 14 individuals (41.2%) belonged to the normal population. A statistically significant difference (P ≤ 0.1) was observed in the prevalence of HPV in oral samples between the two groups. In the eGW group, 61 participants were positive for low-risk HPV (LR-HPV) genotypes, and 4 tested positive for HPV-18. Among the normal population, 14 individuals tested positive for LR-HPV genotypes. Notably, a higher proportion of positive HPV results—approximately 29%—was identified in anal and urinary samples compared to vaginal samples from females in the normal population.

Significant differences in HPV prevalence were noted between individuals with eGW and those in the normal population. Overall, the prevalence of HPV among eGW individuals was approximately twice that of the normal population across the four anatomical sites. Further research is warranted to better understand the association between HPV infection, eGW, and various sociodemographic factors.

The rising prevalence of microbial resistance in Acinetobacter baumannii infections has become a significant public health concern. Researchers are exploring antimicrobial peptides (AMPs) as promising alternatives to traditional antibiotics. Among these, Ib-AMP 4 and Oncorhyncin II have shown notable antibacterial properties.

The primary objective of this study was to produce recombinant peptides for Ib-AMP 4 and Oncorhyncin II. Additionally, the study aimed to investigate their combined effects against A. baumannii (ATCC 19606).

The study focused on the self-directed expression of synthetic genes encoding Ib-AMP 4 and Oncorhyncin II within the Escherichia coli BL21 (DE3) pLysS host expression system. Following purification and optimization, the peptides' biological effectiveness against A. baumannii (ATCC 19606) was evaluated through various assays, including minimum inhibitory concentration (MIC), time-kill, and growth kinetic assessments.

The MIC assay confirmed the ability of Ib-AMP 4 and Oncorhyncin II to inhibit the growth of A. baumannii , with effective concentrations at 111 µg/mL and 80.25 µg/mL, respectively. Moreover, a synergistic effect was observed when Ib-AMP 4 and Oncorhyncin II were combined at 2 × MIC, as demonstrated by the checkerboard method, leading to a rapid reduction in viable cell count. Growth kinetic analysis further revealed a 95% reduction in bacterial turbidity within 5 hours of exposure to the peptide combination.

The production of recombinant Ib-AMP 4 and Oncorhyncin II peptides showed significant efficacy against A. baumannii . Checkerboard, time-kill, and growth kinetic assays consistently demonstrated their synergistic effects. These findings highlight the potential of combining these peptides as an effective strategy to combat A. baumannii infections.

After Aspergillus fumigatus , A. flavus is the second leading cause of invasive and non-invasive aspergillosis. These fungi are of significant epidemiological importance in provinces with dry and hot climates.

In the present study, antifungal susceptibility testing (AFST) and genotyping of sixty-five A. flavus clinical isolates originating from patients in Mazandaran and Tehran were performed.

Antifungal susceptibility testing of 65 clinical isolates of A. flavus was conducted against amphotericin B (AMB), itraconazole (ITR), voriconazole (VOR), posaconazole (POS), isavuconazole (ISA), luliconazole (LUL), lanoconazole (LAN), and 5-fluorocytosine according to the Clinical Laboratory Standards Institute (CLSI) method (M38-A2). The minimum inhibitory concentrations (MICs) were determined for each antifungal drug against all strains. Additionally, microsatellite typing using six variable number tandem repeat (VNTR) markers was performed to assess the genetic diversity and potential relationships among the clinical strains.

Luliconazole had the lowest geometric mean MIC (0.020 μg/mL), followed by LAN (0.021 μg/mL), POS (0.089 μg/mL), ISA (0.115 μg/mL), ITR (0.220 μg/mL), VOR (0.244 μg/mL), AMB (0.870 μg/mL), and 5-fluorocytosine (58.76 μg/mL). Microsatellite typing revealed sixty-five distinct sequence genotypes. Statistically, there was no significant relationship between genotypes and AFST profiles (P ≥ 0.05).

Luliconazole and lanoconazole demonstrated the greatest in vitro activity among all tested antifungals. However, most A. flavus strains exhibited reduced sensitivity to AMB. Microsatellite genotyping indicated no genetic similarity among the clinical strains, revealing high genetic diversity among A. flavus isolates obtained from clinical samples.

The COVID-19 pandemic underscores the need for effective models to study SARS-CoV-2 infection and evaluate antiviral therapies.

This study aimed to develop a human nasal organoid model to assess susceptibility to SARS-CoV-2 and its variants and to evaluate the antiviral effects of compounds such as camostat, remdesivir, and bergamottin.

Nasal organoids were infected with SARS-CoV-2 and HCoV-OC43 pseudoviruses, followed by wild-type and variant strains in a BSL-3 laboratory. Viral content was measured at 2, 24, and 48 hours post-infection using qPCR, and infected cells were identified via immunofluorescence.

The organoids demonstrated susceptibility to SARS-CoV-2 and HCoV-OC43 pseudoviruses (P < 0.001) and were effectively infected with SARS-CoV-2 variants. Remdesivir, hesperidin, and bergamottin exhibited dose-dependent antiviral effects (P < 0.0001).

Human nasal organoids represent a valuable model for studying SARS-CoV-2 infection and evaluating antiviral drugs, particularly for nasal applications in vitro .