Characteristics of Streptococcus agalactiae causing urinary tract infections: Emergence of new sequence types ST74 and ST38 in Iran.

Objectives: Difficult-to-treat Streptococcus agalactiae infections are increasingly described in patients with urinary tract infections (UTIs). This occurrence could be due to the production of virulence determinants. This study aimed to characterize the molecular features of S. agalactiae responsible for UTIs. Materials and Methods: In this cross-sectional study, 70 S. agalactiae isolated from UTIs were examined. Antibiotic susceptibility testing was performed using the disk diffusion method. All S. agalactiae isolates were confirmed by atr and dltS PCR assays. Virulence, alpha protein-like, and pilus island genes were detected by PCR. Isolates were characterized using the multilocus sequence typing method. Results: Multidrug resistance was observed in 80% of isolates. Five virulence profiles were detected, wherein cylE, lmb, bca, rib (35.7%), cylE, lmb, alp3 (27.1%), and cylE, lmb, bac, rib, alp2 (21.4%) were the most frequent detected profiles. S. agalactiae was isolated and categorized within three clonal complexes (CCs) including CC22 (40%), CC17 (25.7%), and CC23 (20%). The main sequence types (STs) found were ST22 (27.1%), ST23 (17.1%), ST17 (12.9%), ST31 (8.7%), ST40 (8.7%), ST74 (7.1%), ST48 (4.3%), ST890 (4.3%), ST189 (2.8%), ST38 (2.8%), ST52 (2.8%), and ST155 (1.4%). ST74 and ST38 were reported for the first time in Tehran-Iran. Conclusion: This study highlights the predominance of the CC22 lineage among S. agalactiae strains isolated from UTIs in Tehran, Iran, and highlights the significant penetration of this lineage into hospitals. MDR patterns among these strains appear to be becoming a major concern in the management of infections.

Autophagy and unfolded protein response induction: a crosstalk between street rabies virus and the host.

The endoplasmic reticulum (ER) response mechanism to cellular stress is mediated by the unfolded protein response/ER-associated degradation (UPR/ERAD) pathway. A viral infection can trigger ER stress and engage some transcription factors, depending on the host cell and virus type, activating or inhibiting autophagy. The relationship between ER response and autophagy in rabies has not been investigated yet. In the present study, the mouse brain was infected with street rabies virus (SRABV). Total RNA was extracted from the brains of animals, and cDNA was synthesized. Next, real-time PCR assay was performed using specific primers. The expression of hypoxanthine-guanine phosphoribosyltransferase (Hprt), CCAAT/enhancer binding protein homologous protein (CHOP), apoptosis signal-regulating kinase 1 (ASK1), activating transcription factor 6 (ATF6), and caspase 3 (CASP3) genes was also investigated. Based on the results, SRABV caused significant changes in the mRNA expression of ATF6, CHOP, and ASK1 genes in the brains of infected mice in the control group (group V). Treatment of infected cells with the pIRES-EGFP-Beclin-1 vector and rapamycin caused changes in nearly most of the parameters. However, alterations in CASP3 gene expression were only observed when the vector and the virus were simultaneously injected into the cells. Overall, protection and autophagy against cell death induced by SRABV infection can be achieved by activating the ER stress pathway, followed by a marked increase in the expression of ATF6, CHOP, ASK1, and CASP3 genes.

In silico design and immunoinformatics analysis of a universal multi-epitope vaccine against monkeypox virus.

Monkeypox virus (MPXV) outbreaks have been reported in various countries worldwide; however, there is no specific vaccine against MPXV. In this study, therefore, we employed computational approaches to design a multi-epitope vaccine against MPXV. Initially, cytotoxic T lymphocyte (CTL), helper T lymphocyte (HTL), linear B lymphocytes (LBL) epitopes were predicted from the cell surface-binding protein and envelope protein A28 homolog, both of which play essential roles in MPXV pathogenesis. All of the predicted epitopes were evaluated using key parameters. A total of 7 CTL, 4 HTL, and 5 LBL epitopes were chosen and combined with appropriate linkers and adjuvant to construct a multi-epitope vaccine. The CTL and HTL epitopes of the vaccine construct cover 95.57% of the worldwide population. The designed vaccine construct was found to be highly antigenic, non-allergenic, soluble, and to have acceptable physicochemical properties. The 3D structure of the vaccine and its potential interaction with Toll-Like receptor-4 (TLR4) were predicted. Molecular dynamics (MD) simulation confirmed the vaccine's high stability in complex with TLR4. Finally, codon adaptation and in silico cloning confirmed the high expression rate of the vaccine constructs in strain K12 of Escherichia coli (E. coli). These findings are very encouraging; however, in vitro and animal studies are needed to ensure the potency and safety of this vaccine candidate.

The effects of nutrition bio-shield superfood powder on immune system function: A clinical trial study among patients with COVID-19.

The present study aimed to evaluate the effects of Nutrition Bio-shield Superfood (NBS) powder on the immune system function and clinical manifestations in patients with COVID-19. We compare the effects of NBS powder on the immune system function and clinical manifestations among two different groups: 1) intervention group receiving standard treatment scheduled according to treatment guidelines plus NBS powder, and 2) control group receiving only the same standard treatment. The serum levels of IL-2, IL-6, IL-17, IFNγ, and TNFα were determined after four weeks of treatment by specific ELISA kits according to the manufacturer's instructions. Finally, the level of immune system stimulation and inflammatory markers were compared at baseline and after intervention in both groups. Data were analyzed using SPSS (version 22). A p-value of ≤ 0.05 was set as significant. A total of 47 patients with COVID-19 (24 patients in the intervention group and 23 patients in the control group) were included in this study. Results showed that the differences in the mean decrease of IL-2, IL-6, and TNF-α in the intervention group in comparison to the control group were 0.93, 10.28, and 8.11 pg/ml, respectively (P<0.001). On the other hand, there was no difference in IL-17, IFNγ, monocytes, eosinophil, and other inflammatory indices between the intervention and control groups. Although NBS powder was able to significantly decrease the levels of some proinflammatory cytokines in patients with COVID-19, however, it is noteworthy that the course of the disease was to large part unaffected by NBS power and there was a reduction independent of treatment. The present study indicates that NBS powder could provide a beneficial anti-inflammatory effect in patients with COVID-19. Hence, NBS in treating patients with COVID-19 shows promise as an adjuvant to the current standard antiviral treatment of such patients. Clinical Trial Registration: https://www.irct.ir, identifier IRCT20200426047206N1.

Association between Influenza and COVID-19 Viruses and the Risk of Atherosclerosis: Meta-Analysis Study and Systematic Review.

There is a lot of evidence to suggest that patients infected with the COVID-19 and influenza viruses are at risk of atherosclerosis. Additionally, there are heterogeneous studies on the risk of arthrosclerosis in patients infected with the influenza and COVID-19 viruses. We conducted a case−control and cross-sectional study and examined the association between the risk of atherosclerosis, and influenza virus (IV-A and IV-B) and COVID-19 infections in this study. We searched for keywords such as influenza virus, COVID-19 and atherosclerosis in English and Persian in well-known databases such as PubMed, SID, Magiran and Google Scholar. In this study, we analyzed the information using a meta-analysis, the random effect model, the I2 index and STAT (version 11.2). The results from the analysis of ten studies on influenza virus and nine studies on COVID-19 reviewed individually (totaling 6428 samples for influenza virus infections and 10,785 samples for COVID-19 infections) demonstrated a risk of arthrosclerosis in patients with influenza and COVID-19 infections, with an OR (odds ratio) = 0.45 ((95% CI): 0.25 to 0.64) and an OR (odds ratio) = 1.04 ((95% CI): 0.82 to 1.26), respectively. The present study provides new insights into the risk of atherosclerosis in patients infected with the COVID-19 and influenza viruses. Therefore, it seems necessary to consider different strategies for managing and eradicating viral infections among individuals.

Mupirocin-Resistant Staphylococcus aureus in Iran: A Biofilm Production and Genetic Characteristics.

The spread of mupirocin-resistant Staphylococcus aureus strains in hospitals and communities is a universal challenge. Limited data is available on the genetic features of high-level mupirocin resistant- (HLMUPR-) S. aureus isolates in Tehran. In the present research, we investigated 48 high-level mupirocin resistance S. aureus by antimicrobial activity, virulence analysis, biofilm formation, multilocus sequence typing (MLST), and staphylocoagulase (SC) typing. All the HLMUPR strains were positive for mupA gene. The frequency of multidrug resistance was 97.9%. Twenty-one (43.8%) were toxinogenic with 14 producing pvl (29.2%), 5 tst (10.4%), and two eta (4.2%). Among the HLMUPR isolates, biofilm production was detected in 45 (89.6%) isolates with complete dominance clfB, clfA genes, and a noticeably high frequency fnbA (95.8%), followed by fnbB (93.8%), eno and icaD (each 83.3%), sdrC (81.3%), ebps (79.2%), icaA (75%), sdrD (66.7%), fib (60.4%), sdrE (50%), cna (41.7%), and bap (4.2%). Coagulase typing distinguished isolates into four genotypic patterns including III (50%), II (27.1%), and type IVa (22.9%). A total of three clonal complexes (CCs) and 4 sequence types (STs) including CC/ST22 as the most prevalent (52.1%), CC8/ST239 (20.8%), CC/ST8 (16.7%), and CC/ST5 (10.4%) were identified in current work. According to our analysis, nonbiofilm producer isolates belonged to CC8/ST239 (6.3%) and CC/ST8 (4.2%). Fusidic acid-resistant isolates belonged to CC/ST45 (n = 3) and CC8/ST239 (n = 1). Observations highlighted the circulation of the CC/ST22 HLMUPR S. aureus strains with strong biofilm-production ability in our hospitals, indicating the possibility of transmission of this type between community and hospital.

An Overview of Antiviral Properties of Bacteriophages with Emphasis on the Treatment of COVID-19 Infection.

Bacteriophages or phages are the most abundant organisms in the biosphere. Scientists considered phages an appropriate tool for understanding molecular biology, horizontal gene transfer vectors, stimulants of bacterial evolution, a source of diagnostic and genetic tools, and new therapeutic agents. Therefore, studying the biology of phages and their interactions with their hosts is crucial to gaining a deeper knowledge of biological systems. Numerous studies confirmed that bacteriophages are a genetic tool with high potential for treating infectious diseases, including bacterial, fungal, and viral infections. Therefore, phages may be used as an appropriate therapeutic target against some viruses, such as COVID-19 infection. In this study, we describe the role of phages in modulating the host immune system, the production of specific antibodies against the COVID-19 virus by the host immune system, and the minimization of damage caused by the COVID-19 virus to the host. Also, the present study expresses our understanding of the prospect of phage therapy as an adjunctive therapy.

Molecular characterization of invasive Staphylococcus aureus strains isolated from patients with diabetes in Iran: USA300 emerges as the major type.

There have been few studies focused on the molecular characterization of invasive Staphylococcus aureus strains in patients with diabetes in Iran. In the present study, 20 invasive S. aureus strains recovered from the patients with diabetes characterized by the virulence and resistance analysis, biofilm formation, staphylocoagulase (SC) typing, S. aureus protein A locus (spa) typing staphylococcal cassette chromosome mec (SCCmec) typing, and multilocus sequence typing (MLST). Virulence gene detection indicated a high prevalence of strains encoding the pvl genes (50%), a low prevalence of the tst and seg gene (each of them was 5%) and a markedly high prevalence of fnbB (95%), fnbA (85%), icaD (75%), icaA (65%). A total of 3 coagulase types (III, 85%; II, 10%; V, 5%), 2 agr types (I, 90%; II 10%) and 2 SCCmec types (IV, 65%; III, 35%) and four different clones namely ST8-MRSA-IV/t008 (50%) (USA300), ST239-MRSA-III/t030 (35%), ST5-MRSA-IV/t002 (10%), and ST45-MRSA-IV/t038 (5%) were detected in this study. Eighty-five percent of the isolates were biofilm producers. All the 4 high-level mupirocin resistance (HLMUPR) strains belonged to CC/ST8-MRSA-IV/t008 clone and carried mupA gene. Fusidic acid-resistant isolate belonged to ST239-SCCmec III/t030 clone. One vancomycin-intermediate resistance isolates was detected in our study, which belonged to ST5-MRSA-IVt002. Circulating clone in MRSA strains (USA300) isolated from the patients with diabetes highlighting the possibility of transmission of these microorganisms' clones between hospital, community, and environments. However, further studies require providing critical insights into the importance of continued controlling and treatment of S. aureus infections in patients with diabetes.

Genetic analysis of methicillin-susceptible Staphylococcus aureus clinical isolates: High prevalence of multidrug-resistant ST239 with strong biofilm-production ability.

BACKGROUND: The distributions of methicillin-susceptible Staphylococcus aureus (MSSA) are divers geographically with different genetic backgrounds. Data related to molecular characteristics of MSSA compare to methicillin-resistant Staphylococcus aureus (MRSA) is sparse. METHODS: In this cross-sectional study, antimicrobial susceptibility testing, virulence genes analysis, biofilm formation, accessory gene regulator (agr) typing, and multilocus sequence typing (MLST) characterized on 75 MSSA isolates. RESULTS: Multidrug-resistance MSSA was found to be 84%. Forty-eight (64%) isolates were toxinogenic with 34 and 14 isolates carrying pvl and tst representing 45.3% and 18.7%. The most common SE genes were sed (20%), sec (16%), and sea (16%). Fifty-five (73.3%) isolates were confirmed as biofilm producer with a markedly high prevalence of fnbA (93.3%), fnbB (86.7%), icaA (65.3%), icaD (53.3%), can (24%), ebp (10.7%), and bap (1.3%). A total of 3 agr types (I, 73.3%; III, 16%; II, 10.7%) and 4 clonal complexes (CCs) and sequence types (STs), namely CC8/ST293 (45.3%), CC/ST22 (28%), CC/ST30 (16%), and CC/ST5 (10.7%) were detected in this study. All the high and low-level mupirocin resistance strains belonged to ST239 and ST22 strains, respectively. All the fusidic acid-resistant isolates carried fusC and belonged to ST30. CONCLUSIONS: These findings indicated that ST239 with strong biofilm production ability is the most common type in MSSA strains isolated from patients. It seems that the antimicrobial resistance profiles, toxin, and biofilm formation were closely associated with specific STs. Further studies are required to identify and control of these clonal lineages in our area.

Prevalence, Genetic Diversity, and Temporary Shifts of Inducible Clindamycin Resistance Staphylococcus aureus Clones in Tehran, Iran: A Molecular-Epidemiological Analysis From 2013 to 2018.

The prevalence of Staphylococcus aureus as an aggressive pathogen resistant to multiple antibiotics causing nosocomial and community-acquired infections is increasing with limited therapeutic options. Macrolide-lincosamide streptogramin B (MLSB) family of antibiotics represents an important alternative therapy for staphylococcal infections. This study was conducted over a period of five years from August 2013 to July 2018 to investigate the prevalence and molecular epidemiology in Iran of inducible resistance in S. aureus. In the current study, 126 inducible methicillin-resistant S. aureus (MRSA) (n = 106) and methicillin-sensitive S. aureus (MSSA) (n = 20) isolates were characterized by in vitro susceptibility analysis, resistance and virulence encoding gene distribution, phenotypic and genotypic analysis of biofilm formation, prophage typing, S. aureus protein A locus (spa) typing, staphylocoagulase (SC) typing, staphylococcal cassette chromosome mec (SCCmec) typing, and multilocus sequence typing. Of the 126 isolates, 76 (60.3%) were classified as hospital onset, and 50 (39.7%) were classified as community onset (CO). Biofilm formation was observed in 97 strains (77%). A total of 14 sequence types (STs), 26 spa types, 7 coagulase types, 9 prophage types, 3 agr types (no agr IV), and 9 clonal complexes (CCs) were identified in this study. The prevalence of the inducible MLSB (iMLSB) S. aureus increased from 7.5% (25/335) to 21.7% (38/175) during the study period. The iMLSB MRSA isolates were distributed in nine CCs, whereas the MSSA isolates were less diverse, which mainly belonged to CC22 (7.95%) and CC30 (7.95%). High-level mupirocin-resistant strains belonged to ST85-SCCmec IV/t008 (n = 4), ST5-SCCmec IV/t002 (n = 4), ST239-SCCmec III/t631 (n = 2), and ST8-SCCmec IV/t064 (n = 2) clones, whereas low-level mupirocin-resistant strains belonged to ST15-SCCmec IV/t084 (n = 5), ST239-SCCmec III/t860 (n = 3), and ST22-SCCmec IV/t790 (n = 3) clones. All the fusidic acid-resistant iMLSB isolates were MRSA and belonged to ST15-SCCmec IV/t084 (n = 2), ST239-SCCmec III/t030 (n = 2), ST1-SCCmec V/t6811 (n = 1), ST80-SCCmec IV/t044 (n = 1), and ST59-SCCmec IV/t437 (n = 1). The CC22 that was predominant in 2013-2014 (36% of the isolates) had almost disappeared in 2017-2018, being replaced by the CC8, which represented 39.5% of the 2017-2018 isolates. This is the first description of temporal shifts of iMLSB S. aureus isolates in Iran that identifies predominant clones and treatment options for iMLSB S. aureus-related infections.

Molecular Characterization, Drug Resistance and Virulence Analysis of Constitutive and Inducible Clindamycin Resistance Staphylococcus aureus Strains Recovered from Clinical Samples, Tehran - Iran.

BACKGROUND: Macrolide-lincosamide streptogramin B family is one of the important alternative antibiotics for treating staphylococcal infections. The aim of this study was to determine the characteristics and prevalence of antibiotic resistance genes in different coagulase types of clinical Staphylococcus aureus strains. METHODS: In the present study, 86 isolates with different phenotypes of MLSB resistance were investigated. In vitro susceptibility was assessed by the disk diffusion and broth microdilution methods. PCR assays were used to detect resistance-related genes. Coagulase and SCCmec types were identified by multiplex PCR assay. RESULTS: The prevalences of constitutive MLSB, inducible MLSB, and MS phenotypes were found to be 23%, 14.2%, and 4.9%, respectively. The rates of resistance to mupirocin, fusidic acid, and tigecycline were found to be 9.3%, 4.6%, and 2.3%, respectively. The top three predominant resistance genes were mecA, tet(M), erm(C) representing 75.6, 50, and 40.7% of isolates. mupA (7%), fusB (3.5%), and fusC (1.2%) genes were also detected among tested isolates. Coagulase types were mainly type II (34.9%), followed by III (32.6%), V (20.9%), and I (11.6%). CONCLUSION: These findings indicated high resistance rate and low genetic variability with the prominence of coa type II, highlighting the particular importance of diagnosis of these strains to avoid treatment failure.

A phylogenetic study of new rabies virus strains in different regions of Iran.

Rabies is the most critical zoonotic disease in Iran, which imposes many extra costs on health care system in each country. The present study aimed to determine the molecular characteristics of the wild circulating strains of the rabies virus (RABV) collected in Iran during 2015-2017. Rabies-suspected samples were collected from different regions of Iran and identified for RABV antigen confirmation using fluorescent antibody tests. Polymerase chain reaction (PCR) was performed on positive samples and gene sequencing was done on rabies nucleoprotein and glycoprotein genes to determine the rabies molecular characteristics. Accordingly, nine street RABVes were isolated. Then, N (802 bp) and G (735 bp) genes were amplified with specific primers using PCR. The sequence of nine strains was determined and compared with another 50 close to them, and the phylogenetic tree was plotted using neighbor-joining method by Mega 7 software. The molecular characteristic results indicated that all new strains belong to RABV wild species. As a result, the most prevalent strains of RABV in northwest, west, center, and south of Iran were identified. The present study may provide a better insight into the identification of all RABV strains, and understanding the evolutionary nature of RABV and how its hosts change in the world over the centuries.

Comparison of Reverse Transcription Loop-Mediated Isothermal Amplification Method with SYBR Green Real-Time RT-PCR and Direct Fluorescent Antibody Test for Diagnosis of Rabies.

Rabies as an endemic disease in most Asian and African countries, especially in remote areas, and requires a reliable diagnostic method. This study aimed to develop a reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for rapid detection of rabies virus RNA in the brain samples, compared to SYBR Green real time RT-PCR test as a molecular technique and direct fluorescent antibody test as a serological method. In this study, RT-LAMP was developed to diagnose rabies. Six primers were designed based on the nucleoprotein (N) of rabies virus. The sensitivity and specificity of SYBR Green real-time RT-PCR and RT-LAMP methods were also determined.RT-LAMP was optimized at 58 ℃ for 60 min. The sensitivity and specificity of RT-LAMP and SYBR Green real-time RT-PCR were 91.2% and 84.2%, and 94.12% and 88.9%, respectively. The slight difference between the sensitivity and specificity of RT-LAMP and that of SYBR Green Real-Time RT-PCR demonstrated that RT-LAMP could be used as a reliable and cost-effective method for the diagnosis of rabies.

Genetic Variability of Methicillin Resistant Staphylococcus Aureus Strains Isolated from Burns Patients.

OBJECTIVES: Staphylococcus aureus is a nosocomial pathogen that provides a major challenge in the healthcare environment, especially in burns units where patients are particularly susceptible to infections. In this study, we sought to determine molecular types of S. aureus isolates collected from burns patients, based on staphylococcal protein A and coagulase gene polymorphisms. METHODS: Antibiotic susceptibility testing of 89 S. aureus strains isolated from burn wounds of patients was assessed using the Kirby-Bauer disk diffusion method. Strains were characterized by spa typing, coa typing, and resistance and toxin gene profiling. RESULTS: A total of 12 different spa types were identified with the majority being t790 (18%). Panton-Valentine leucocidin encoding genes were identified in spa types t044 (5.6%), t852 (2.2%) and t008 (2.2%). The most commonly detected antibiotic resistance gene was ant (4')-Ia (60.7%). Ten different coa types were detected and the majority of the tested isolates belonged to coa III (47.2%). All the high-level mupirocin-resistant and low-level mupirocin resistant strains belonged to coa type III. CONCLUSION: The present study illustrated that despite the high frequency of coa III and spa t790 types, the genetic background of S. aureus strains in Iranian burns patients was diverse. The findings obtained are valuable in creating awareness of S. aureus infections within burns units.

Genotype Distribution of Panton-Valentine Leukocidin (PVL)-Positive Staphylococcus aureus Strains Isolated from Wound-Related Infections: a Three-Year Multi-Center Study in Tehran, Iran.

The spread of Panton-Valentine leucocidin (PVL)-carrying S. aureus strains in patients with wound infections in both the community and hospitals is increasing in some areas of Iran. In the present study, we determined the molecular characteristics and distribution of PVL-producing S. aureus strains isolated from wound infections. Genes encoding resistance, toxins, and staphylococcal enterotoxins were analyzed by polymerase chain reaction assays. Genotyping was performed using multi-locus sequence typing. Aminoglycoside resistance genes including ant (4')-Ia (57.4%) and aac (6')-Ie/aph (2″) (45.7%) were the most prevalent genes in isolates. Staphylococcal enterotoxin type A, as the most frequent type, was present in 20.2% of isolates. Strains belonged to seven clonal complexes. The most frequent clonal complex was CC30 (ST30) (29.8%), followed by CC22 (ST22) (21.3%), CC8 (ST8 and ST931) (17%), CC88 (ST88) (10.6%), CC59 (ST59 and ST338) (8.5%), CC1 (ST772 and ST1) (7.5%), and CC15 (ST15) (5.3%). Our findings indicated an increasing trend of CC30, carrying a wide range of resistance and toxin genes, which could present an obstacle in the treatment of patients with wound infections. Further studies are required to investigate the carriage of resistance, the antibiotic susceptibility pattern, and toxins encoding genes in different molecular types.

Natural Infection with Rabies Virus: A Histopathological and Immunohistochemical Study of Human Brains.

OBJECTIVES: Despite all the efforts and increased knowledge of rabies, the exact mechanisms of infection and mortality from the rabies virus are not well understood. To understand the mechanisms underlying the pathogenicity of rabies virus infection, it is crucial to study the tissue that the rabies virus naturally infects in humans. METHODS: Cerebellum brain tissue from 9 human post mortem cases from Iran, who had been infected with rabies virus, were examined histopathologically and immunohistochemically to evaluate the innate immune responses against the rabies virus. RESULTS: Histopathological examination revealed inflammation of the infected cerebellum and immunohistochemical analyses showed an increased immunoreactivity of heat shock protein 70, interleukin-6, interleukin-1, tumor necrosis factor-alpha, caspase-3, caspase-9, toll-like receptor3 and toll-like receptor4 in the infected brain tissue. CONCLUSION: These results indicated the involvement of innate immunity in rabies infected human brain tissue, which may aggravate the progression of this deadly disease.

Genetic Diversity Analysis of Methicillin-resistant Staphylococcus aureus Strains Isolated from Intensive Care Unit in Iran.

OBJECTIVES: Staphylococcus aureus has emerged as a major public health concern. It is a common pathogen in high-risk hospital intensive care units (ICUs). We analyzed the molecular characteristics on the SCCmec and spa genes of S. aureus isolates gathered from ICUs. The antibiotic resistance patterns and carriage of resistance and virulence determinants were also identified. METHODS: In this cross-sectional study, 84 non-duplicated S. aureus strains isolated from ICU patients in were genotyped using SCCmec and spa typing. The Kirby-Bauer disk diffusion and micro-broth dilution methods were used to determine resistance patterns. Virulence and resistance gene profiling were also determined using the polymerase chain reaction technique. RESULTS: All isolates were methicillin-resistant S. aureus and belonged to seven spa types: t388 (36.9%), t852 (14.3%), t924 (13.1%), t790 (11.9%), t064 (10.7%), t037 (9.5%), and t084 (3.6%). They differed in the carriage of resistance and toxin genes. The most common SCCmec type was III detected in 50 isolates (59.5%), followed by type IV in 34 isolates (40.5%). The pvl gene was detected in 14.3% (n = 12) of isolates, of which 66.7% (n = 8) belonged to t852 and 33.3% (n = 4) belonged to t790. Among the tested strains, 9.5% (n = 8) carried the mupA gene and belonged to the t064 spa type. CONCLUSIONS: The data revealed a high resistance rate to antibiotics, which could be a threat to ICU patients. It is necessary to detect antimicrobial resistance and resistance and toxin-encoding of gene profiles in different molecular types.

Genetic diversity and biofilm formation analysis of Staphylococcus aureus causing urinary tract infections in Tehran, Iran.

INTRODUCTION: Over the past decades, prevalence of biofilm-forming Staphylococcus aureus strains has significantly increased in urinary tract infections. The aim of this study was to investigate prevalence of biofilm forming and adhesion encoding genes and to analyze distribution of different agr and spa types in S. aureus isolates. METHODOLOGY: In the present study, 75 S. aureus isolates obtained from patients with urinary tract infections were examined for susceptibility to antimicrobial agents. Adhesion, biofilm, and spa encoding genes were detected by PCR screening; agr types were determined using multiplex PCR. RESULTS: Among the 75 isolates, 72% were biofilm producers and 28% were non-biofilm producers. Notably, the ability to produce biofilm was higher among MRSA strains ompared to MSSA strains. The most prevalent biofilm forming gene was icaD (77.3%), followed by icaA (76%), icaB (57.3%) and icaC (50.7%). Adhesion genes clfA, clfB, fnbB, can, fnbA, ebp and bap were detected in 94.7%, 92%, 68%, 64%, 64%, 60% and 5.3% of the isolates, respectively. The spa types t426 and t7789 were found among the non-MDR isolates. It was found that t790, t084, t7789 and t325 spa types were biofilm producers, while t426 and t1339 spa types were non-biofilm producers. CONCLUSION: Biofilm encoding genes icaD and spa type t790 and agr type III were the most prevalent factors among MDR biofilm producer isolates. The study emphasized that identification of genes and characterization of molecular types involved in biofilm formation should be considered.

Genetic Diversity Analysis of Mupirocin-Resistant Staphylococcus aureus Clinical Isolates in Tehran Hospitals, Iran.

Few studies describe the molecular characterization of mupirocin resistance in Staphylococcus aureus strains. In this study, we evaluated the characteristics of mupirocin resistance in S. aureus isolates for 1-year period in Tehran, Iran. In a cross-sectional study, we collected 51 unique mupirocin-resistant strains obtained from 648 S. aureus isolates. High- and low-level resistance were determined by minimum inhibitory concentration with broth microdilution method. Presence of the genes for resistance to antibiotics and toxins was detected by polymerase chain reaction assays. Genotyping was performed by S. aureus protein A (spa) and staphylococcal cassette chromosome mec (SCCmec) typing, whereas clones were determined by multilocus sequence typing. Among mupirocin-resistant isolates, methicillin-resistant S. aureus (MRSA) 23 (45.1%) and 28 (54.9%) isolates were classified as high- and low-level mupirocin resistance, respectively. Among the 51 tested strains 25 (49%) isolates were positive for mupA genes. Seven different clones were detected in this study. High-level mupirocin-resistant (HLMUPR) strains belonged to ST8-SCCmec IV/t064 (n = 10, 19.6%), ST5-SCCmec IV/t002 (n = 5, 9.8%), ST8-SCCmec IV/t008 (n = 4, 7.8%), and ST239-SCCmec III/t631 (n = 4, 7.8%) clones, while low-level mupirocin-resistant (LLMUPR) strains belonged to ST22-SCCmec IV/t790 (n = 11, 21.6%), ST239-SCCmec III/t860 (n = 9, 17.7%), and ST15-SCCmec IV/t084 (n = 8, 15.7%) clones. Two strains belonged to ST22-SCCmec IV/t790 clone, despite carrying mupA gene, and demonstrated LLMUPR phenotype. One ST8-SCCmecIV/t008 strain with HLMUPR was confirmed as Vancomycin-intermediate S. aureus strain. Our data demonstrated the need for thorough epidemiological monitoring and a routine mupirocin testing program to prevent and detect mupirocin resistance in MRSA.

Ante-mortem Diagnosis of Human Rabies Cases Using SYBR Green Real-Time PCR.

BACKGROUND: Rabies, as the most important zoonotic disease, is transmitted through a bite or scratch by an infected domestic or wild carnivores and bats or contact of open wound with infected saliva. The fluorescent antibody test (FAT) is the "gold standard" diagnostic method for suspected brain samples. For close monitoring of unknown encephalitis, rabies surveillance, and also the limitations for post-mortem diagnosis of rabies in human and performing fast prophylactic measures for other individuals in contact with rabid patients, ante-mortem diagnosis based on molecular methods such as real-time polymerase chain reaction (PCR) seems to be more reliable. In this study, we detected 2 positive rabid cases using SYBR Green real-time PCR for the first time in Iran. METHODS: In this study, 3 saliva samples at intervals up to 6 hours were collected from any of the nine suspected patients with nonspecific symptoms between March 2016 and March 2017. Total RNA extraction, cDNA synthesis and real-time PCR were performed along with confirmed negative and positive controls. Then, we tracked the patients for follow-up and understanding of their status. On brain samples of patients who died, FAT and MIT (mouse inoculation test) were performed to obtain definitive results. RESULTS: In this study, the patients were 4 females and 5 males, between 8 and 80 years old from different geographical areas of Iran. The ante-mortem saliva samples of 2 out of nine patients who died were positive by SYBR Green real-time PCR. Positive results of FAT test on these samples confirmed the presence of rabies virus infection in their brains and also the ante-mortem diagnosis results. CONCLUSION: The results of this study suggest that SYBR Green real-time PCR technique on saliva sample can be used as an applicable method for ante-mortem diagnosis of rabies to avoid infection of other people such as the treating medical staff or family members of the patient.