Iranian Journal of Microbiology最新文献

Background and objectives: Vitamin D deficiency in viral infection associated with autoimmune diseases is well documented. This study assessed the prevalence of JC virus in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and its correlation with vitamin D level.

Materials and methods: Serum and urine samples were collected from 50 patients with RA and SLE. DNA was extracted and subjected to PCR test. Positive PCR products were sequenced, phylogenetic tree was constructed to determine the JC virus genotype. The patient's vitamin D level was evaluated.

Results: Of 50 patients, 19 (38%) were diagnosed as RA, and 31 (62%) were identified as SLE. JC virus DNA was detected in 17 (34%) patients' urine samples including 5 (26.3%) RA and 12 (38.7%) SLE cases. JC virus DNA was detected 2 (4%) in patients' serum samples (one RA. and one SLE). JC virus genotype 3A was dominant. Interestingly, the SLE patients with positive JC virus showed lowered vitamin D compared to patients with negative JC virus (P<0.005).

Conclusion: Given the high rate of JC virus, DNA detection and susceptibility of patients for PML development, it is recommended that detection of JC virus DNA and vitamin D level should be implemented for patients with RA/SLE prior to treatment.

Background and objectives: Brucellosis, a zoonotic bacterial disease caused by Brucella, affects humans and domestic animals, leading to significant economic loss. This study examined suspected cases in North Khorasan, Iran, to understand the prevalence of infection and its characteristics in this region.

Materials and methods: Blood specimens were collected from 200 patients suspected of brucellosis after obtaining informed consent. Serum samples were tested using RBPT, Wright, and 2-ME agglutination tests. Blood samples were cultured on Brucella agar, and positive cultures underwent biotyping and PCR assays. A questionnaire identified correlated risk factors.

Results: RBPT, Wright, and 2-ME tests showed 25% brucellosis seroprevalence in symptomatic patients. In contrast, the prevalence was 2.5% among those with positive blood cultures. Notably, all culture-positive patients were also serologically positive, with titers exceeding 1:320 in Wright and 2-ME tests. Most positive cases were in people in their 30s, with B. melitensis biovar 1 identified as the causative agent, and the results were confirmed by multiplex PCR. Significant risk factors include contact with livestock and consumption of raw milk (P < 0.0001).

Conclusion: The findings highlighted the importance of comprehensive diagnostic approaches for accurate identification of brucellosis. Furthermore, education regarding close contact with animals and pasteurization of dairy products is essential for controlling human brucellosis.

Background and objectives: The biofilm formation has been widely recognized as one of the main mechanisms of antimicrobial resistance development in microorganisms. However, few studies are focusing on this phenomenon in Candida spp. in clinical settings, especially on immuno-compromised patients.

Materials and methods: In this study, both the rate of biofilm formation in those patients and its drug susceptibility in initial and mature biofilm were assessed using crystal violet assay and dilution method.

Results: The results demonstrated that the biofilm formation rate was similar between albicans and non-albicans Candida. However, the biofilm formation capacity was more pronounced in non-albicans Candida, especially, C. glabrata. As expected, there was a significant relationship between biofilm formation and drug resistance. In addition, our study reconfirmed that the age of high concentration of antifungal agents only affected Candida before its biofilm formation regardless of its biofilm formation capacity. In the contrary, once the biofilm was formed even elevated drug concentrations did not show sufficient efficacy, highlighting a need for high dosage at the early stage of treatment for those patients.

Conclusion: The results of this study highlighted the importance of using appropriate antifungal agents for Candida treatment before the formation of biofilm.

Background and objectives: The rapid spread of Newcastle disease (ND), driven by extensive commercial exchange in the poultry industry, necessitates urgent preventive measures. Although effective vaccines against the Newcastle disease virus (NDV) have been used since 1940, recent outbreaks and the limitations of current vaccines highlight the need for improved solutions. Advances in synthetic biology, reverse vaccinology, molecular biology, and recombinant DNA technology over the past 20 years have led to the development of recombinant vaccines, which offer enhanced protection and broader immunogenic coverage against NDV. This study aimed to express the immunogenic domains of Hemagglutinin Neuraminidase (HN) and Fusion (F) glycoproteins, linked to the heat-labile enterotoxin B subunit (LTB) bio-adjuvant, to develop an effective and reliable recombinant vaccine for NDV.

Materials and methods: In this study, the L(HN)2F protein, composed of the LTB bio-adjuvant and the immunogenic regions of the doubled Hemagglutinin Neuraminidase (HN-HN) and Fusion (F) epitope, was expressed in Escherichia coli. Subcutaneous injection was used to evaluate the humoral immune response in mice and the result was compared with B1 vaccine.

Results: The induction of strong humoral immune responses proved the strong immunoreactivity of the recombinant protein.

Conclusion: The IgG elicited by the recombinant proteins was comparable to that of the commercial B1 vaccine against NDV, indicating its potential as a viable candidate for further development and evaluation as a recombinant vaccine against NDV.

Background and objectives: Researchers have focused on Staphylococcus aureus because it is transmitted through food, such as milk and dairy products, and causes human diseases. Prevalence, antimicrobial resistance, presence, and distribution of methicillin-resistant S. aureus (MRSA) virulence genes isolated from raw milk and dairy products were evaluated.

Materials and methods: 300 samples of dairy products were collected from Shahrekord, Iran. S. aureus was identified using biochemical tests and screened for sensitivity to 13 antibiotics to identify resistance genes. In addition, SCCmec typing was performed.

Results: Out of 300, S. aureus was found in 82 samples. Raw milk had the highest contamination with S. aureus (60 of 82), followed by cheese (15 of 82), and butter (7 of 82). At least one resistance gene was present in every isolate of S. aureus. Virulence factors and enterotoxin-coding genes, such as sea, seb, sec, and sed were highly distributed.

Conclusion: The results of this study revealed the presence of toxin-producing MRSA strains in raw milk and dairy products. MRSA in dairy farms is an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for controlling the presence of S. aureus, especially MRSA, in dairy products.

Background and objectives: The capability to cause invasive infection, multi-drug resistance, and health care-associated outbreaks of Candida auris have made it a pathogen of great concern. Estimating how many patients in our intensive care unit had C. auris colonization and what characteristics put patients at risk for having Candida spp. colonization were the primary goals of the study.

Materials and methods: Swabs from axilla and groin were collected from 229 patients getting admitted to the ICU. Samples were inoculated into CHROMagar^TM Candida Plus medium. Colonies presumptively identified as C. auris by the presence of light blue with blue halo and were confirmed by VITEK-2.

Results: Our study showed that only one patient was colonized with C. auris. A total of 47 (20.5%) patients were colonized with Candida spp., of which Candida parapislosis was the predominant organism. History of antibiotic use and cerebrovascular accident were independent risk factors in Candida colonization.

Conclusion: Active screening for Candida auris in all patients is not required in our hospital as the prevalence was very low and not cost-effective. Therefore we plan to modify our screening strategy and use risk factors based surveillance strategy as it may serve as an ideal strategy.

Background and objectives: Healthcare workers in hospitals are exposed to infectious diseases that occur in the hospital making them a source of infection for the patients. It is interfaced as cross-contamination agents for MRSA and MR-CoNS, and preventive measures need to be adapted accordingly. The study aimed to assess Methicillin-Resistant Staphylococcus (MRS) on the skin and nasal cavities of healthcare workers (HCWs) and identifying isolates to the species level.

Materials and methods: Swab samples were cultured on mannitol salt agar (MSA) to obtain MRS and determine their ability to produce coagulase. Their susceptibility to antibiotics were determined by agar screening and disk diffusion methods and further identification was done at the species level.

Results: The highest percentage of methicillin resistant coagulase positive Staphylococci (MRCoPS) was reported among skins of male HCWs, (71.4%) were identified as MRSA. The highest levels of methicillin resistant coagulase negative Staphylococci (MRCoNS) were mainly detected in both nasal cavities, (75%) were identified as MRSE. MRSA was reported from doctors (p-value 0.033), whereas the highest incidence of MRSE was obtained from the nurses (p-value 0.048).

Conclusion: This study highlighted that incidence of MRSA was mainly detected in doctors and MRCoNS in both nasal cavities. The highest percentage of MRCoNS was recovered from the patients' room followed by the reception table. Moreover, vancomycin is suggested to be highly effective in managing and controlling S. aureus, MRSA- and MRSE related infections.

Background and objectives: Gastric cancer (GC) is the third most common cause of cancer-related mortality. Epstein-Barr virus (EBV) is associated with several human tumors. The present research was performed to investigate the prevalence of EBV-associated gastric cancer (EBVaGC) among Iranian patients.

Materials and methods: Seventy cases of gastric cancer and 30 cases of gastric ulcer, all preserved in formalin-fixed paraffin-embedded (FFPE), were examined in a case-control study conducted between 2011 and 2018. The specimens underwent analysis to detect the presence of the EBV genome using a Nested-PCR method targeting EBNA1. Subsequently, samples testing positive for the EBNA1 underwent further testing for the presence of the EBER gene using PCR. Finally, Positive samples were subjected to sequencing.

Results: Five out of 70 cases (7%) were found to be positive for EBV based on EBNA1 testing, while all EBNA1 positive samples were negative for EBER. Notably, EBV was not detected in patients with gastric ulcer. The mean age of EBV-positive gastric carcinomas pateints was 64.5 years. Within this group, 60% were male and 40% were female. A higher prevalence of EBV association was observed in diffuse-type cases, with 60% (3 out of 24) testing positive, compared to intestinal-type cases where 40% (2 out of 46) were EBV-positive. Most cases of EBVaGC belonged to grade Ⅰ.

Conclusion: This research demonstrates a low prevalence of EBVaGC in Iran. Discrepancies in EBVaGC occurrence among countries could be attributed to epidemiological variables and dietary practices. A comprehensive studies will provide significant contributions to understanding of its etiology.

Leprosy in children is considered as an indicator of active disease transmission in the community. We report about a seven-year-old male from Telangana, India, with anesthetic skin lesions and familial leprosy history. Clinical examination revealed multiple, dry, scaly, hypopigmented, well-defined, raised punched out anesthetic skin lesions all over the body with both ulnar nerves enlarged. On clinical and laboratory examination, the child was diagnosed with borderline-borderline (BB), multibacillary (MB) leprosy, and Type-1 reaction. The child received a weight-adjusted MB multidrug therapy regimen and corticosteroids for type-1 reactions. This case emphasizes the need for contact tracing and screening for early diagnosis of child leprosy to prevent complications like leprosy reactions which are the risk factors for disability.

Background and objectives: Graft-versus-host disease (GvHD) frequently complicates hematopoietic stem cell transplantation (HSCT). Emerging evidence suggests a correlation between gut microbiota and GvHD risk. This study aims to elucidate the microbiota profiles in HSCT patients before and after transplantation and their association with GvHD.

Materials and methods: This study, conducted from December 2022 to December 2023, involved the collection of 15 stool samples from HSCT patients. Bacterial content was quantified using real-time PCR, while interleukin-6 levels were assessed via ELISA.

Results: Among the 15 participants (8 male, 7 female), 9 underwent allogeneic HSCT (allo-HSCT) and 6 received autologous HSCT. In the aGvHD group, there was a significant reduction in the abundance of Bacteroides and Bifidobacterium compared to those without aGvHD. Additionally, declines were observed in Clostridium and Firmicutes populations. The genus Blautia also showed reduced prevalence in the aGvHD group, whereas no significant differences were noted in the uncomplicated group. ELISA analysis revealed that interleukin-6 levels remained within the normal range (30-960 pg/ml) with no significant elevation in the aGvHD group.

Conclusion: The study highlights a notable association between alterations in gut microbiota, specifically reductions in certain bacterial populations and the development of aGvHD following allo-HSCT.