Infection Epidemiology and Microbiology
Year:2019 | Volume:5 | Issue:4|Papers Count:6

Aim: Group A Streptococcus (GAS) is the causative agent of several invasive and non-invasive diseases. Several virulence factors contribute to the pathogenesis of GAS, such as M protein, hemolysins, and extracellular enzymes. Due to the improper use of antibiotics, the resistance of these microorganisms to antibiotics is increasing. Bacteriocins as an alternative to antibiotics are of great importance. In this study, the effect of antimicrobial Bacteriocin nisin was investigated on the expression of smeZ gene. Materials & Methods: Samples were taken from the site of infection on the skin surface of the patients at the dermatology clinics of Tehran public hospitals. The specimen was immediately transferred to the primary culture medium or basal medium. Chromosomal DNA extraction was performed using the standard method for the extraction of Streptococcus pyogenes genomes. Multiplex PCR was performed to identify the presence of smeZ, speI, and speH genes in the isolates. The expression of smeZ gene was evaluated using the real-time PCR technique. Findings: The frequencies of smeZ, speI, and speH genes in 12 S. pyogenes isolates were 25, 8. 3, and 8. 3%, respectively. The fold change rate for smeZ gene was-1. 209, indicating that this gene was decreased 1. 209 folds in the treated group compared to the untreated group. Conclusion: Bacteriocin not only reduces the number of pathogens but may also affect the metabolism of the bacteria by producing toxins. The use of new antimicrobial agents in place of previous drugs for psoriasis patients could be considered as a way to treat the disease more effectively in the future.

Aims: Following the emergence of methicillin-resistant Staphylococcus aureus (MRSA) isolates, the use of other antibiotics especially vancomycin in S. aureus infections has become inevitable, leading to the emergence of vancomycin-resistant S. aureus (VRSA) strains, which is considered as a major public health concern. This study aimed to determine the vancomycin susceptibility patterns of S. aureus clinical isolates in order to evaluate the current status of vancomycin resistance in the southwest of Iran. Materials & Methods: In this study, 100 S. aureus clinical strains were collected from the hospitals of Khuzestan province in the southwest of Iran. Next, antibiotic susceptibility, vancomycin resistance, and the presence of mecA, vanA, vanB, vanC, and vanD genes were investigated in these isolates. Findings: It was found that 1 and 2 isolates were vancomycin-intermediate S. aureus (VISA) and VRSA, respectively. All three strains showed methicillin-resistance pattern and carried mecA gene. vanA gene was detected in VRSA strains, whereas vanB, vanC, and vanD genes were detected in none of these isolates. Conclusion: This study findings could be alarming regarding the emergence and spread of VRSA strains; therefore, the principles of infection control should be employed in the healthcare systems to prevent the spread of VRSA strains in healthcare facilities.

Background: Bacterial meningitis is a devastating infection associated with significant morbidity and mortality rate among neonates and young children. Early identification and treatment of the causative agents of meningitis is crucial due to high fatality rate in untreated cases. The present study aimed to investigate the common bacterial etiology and occurrence of antimicrobial resistance in patients suspected to meningitis in southwestern Iran. Materials & Methods: This retrospective cross-sectional study was conducted during a five-year period from January 2011 to January 2016 at two major hospitals in southwestern Iran. CSF samples were aseptically collected in BACTECTM, and conventional methods were used for the bacteria isolation and identification. Antimicrobial susceptibility tests were done using disk diffusion and E-test methods. Findings: Out of 89 CSF samples collected from children under 17 years, the number of culture positive specimens was 21 (23. 6%). The highest number of culture positive cases was observed in patients younger than 5 years (57. 1 %). The most frequent pathogens were Streptococcus pneumonia (N = 10, 47. 6%), followed by Haemophilus spp. (N = 3, 14. 3%), and Neisseria meningitidis (N = 3, 14. 3%). Antibacterial susceptibility testing results showed that S. pneumoniae isolates were mostly susceptible to vancomycin and chloramphenicol. Moreover, among N. meningitides and Haemophilus isolates, the most effective in vitro drug was ceftriaxone (100%). Conclusions: These results showed the promising activity of several locally available antibiotics against S. pneumoniae, Haemophilus spp. and N. meningitides, as the most common causative agents of bacterial meningitis in Iranian children. Therefore, such regional studies help prevent and control the burden of infections.

Objectives: The present study aimed to investigate the prevalence of Salmonella serotypes in slaughtered broilers in Kermanshah province and investigate the susceptibility of isolated Salmonella to antibiotics. Methods: In this cross-sectional, 10 carcasses were randomly selected from each of 25 slaughtered broiler flocks that were obtained from their cloacae. This study was conducted in 2014 in Kermanshah province. Samples were transferred into the Selenite F enrichment broth and incubated at 43 ° C for 12-18 h. Antibiotic susceptibility pattern of all isolates to be performed using the disk diffusion method. Also, the agglutination test on slide was performed on Salmonella isolates using the specific antisera to detect Salmonella serotypes. Findings: In the present study, 250 (33%) samples of Salmonella were isolated from 750 cloacal samples of broilers. After serotyping, the most frequent serotype was as follow: Enteritidis serotype (55. 2%), Infantis serotype (38%) and Typhimurium serotype (25. 6%). The results of antibiotic susceptibility pattern indicated that 100% of strains were susceptible to gentamicin, enrofloxacin, imipenem and ceftriaxone; and the highest resistance was observed to nalidixic acid and nitrofurantoin. Furthermore, 202 (80%) out of 250 Salmonella isolates had multiple resistance to three or more antibiotics and accounted as MDR isolates. Conclusion: According to the results of the present study, it is essential to detect pollution sources and pathogenic serotypes, the possibility of transferring Salmonella through poultry to humans and increasing the frequency of resistant isolates to antibiotics. It is strongly recommended to avoid the overuse of antibiotics without performing antibiotic susceptibility patterns.

Backgrounds: Sepsis is a systemic inflammatory response syndrome triggered by an infectious agent and an important cause of admission to intensive care units (ICU), especially in immunodeficient patients. The aim of this study was to determine the spectrum of bacterial etiology and antibacterial susceptibility pattern of sepsis and urinary tract infections (UTIs) in Iranian HIV-infected patients. Materials & Methods: This retrospective cross-sectional study was conducted on HIV/AIDS patients for a period of ten years from January 2005 to January 2015 at two major hospitals in southwestern Iran. Standard microbiological methods were used for the isolation and identification of bacteria from samples. Antimicrobial susceptibility tests were done using disk diffusion method. Findings: Out of 228 samples collected, the frequency of culture-positive blood and urine samples was 23. 2% (n = 53) and 9. 6% (n=22), respectively. Among culture-positive blood samples, Staphylococcus aureus (N = 17, 32. 1%) and Pseudomonas (N = 5, 9. 4%) were the main etiologic agents. While among 22 culture-positive urine samples, the predominant bacteria were Enterococci (N = 7, 31. 8%) and Escherichia coli (N = 5, 22. 7%). Antibacterial susceptibility testing results showed that Gram-positive bacteria were mostly susceptible to vancomycin, rifampin, and co-trimoxazole; meanwhile, Gram-negative bacteria were mostly susceptible against tobramycin, amoxicillin/clavulanate, and aztreonam. Conclusions: In summary, this study findings highlighted the emergence and spread of opportunistic infections and a high level of antibiotic resistance among HIV-infected patients; therefore, restricted infection control strategies must be pursued in these hospitals.

Aims: Influenza A virus subtype H1N1, known as H1N1 influenza virus, could cause moderate to severe swine influenza in humans. H1N1 influenza is associated with high mortality rate. Effective symptom management could significantly reduce the mortality rate. This study aimed to determine the clinical manifestations, outcomes, and predictors of mortality in patients with H1N1 influenza, admitted to hospitals during January to September 2016. Materials & Methods: This retrospective descriptive-analytical study was conducted during January to September 2016 in eight hospitals located in Razavi Khorasan province, northeastern Iran. The medical records of 65 patients were retrieved, and the necessary data were extracted from the records using a demographic questionnaire and a clinical manifestations checklist. The SPSS software Version 23. 0 was used to analyze the data via the measures of descriptive statistics and the logistic regression analysis with odds ratio. findings: The most common clinical manifestations of H1N1 influenza were headache (70. 8%), numbness in the extremities (63. 1%), myalgia (60%), cough (58. 5%), fever and shivering (53. 8%), and nausea (53. 8%). In total, 14 (21. 53%) patients had died due to H1N1 influenza. The significant predictors of death were dyspnea (OR: 13. 91, p: . 032), myalgia (OR: 0. 04. p: . 010), and age (OR: 1. 05, p: . 024) so that dyspnea and myalgia were associated with 13. 9 and 0. 04 times higher odds of death, respectively. Moreover, each one year increase in age was associated with 5% increase in the odds of experiencing death. Conclusions: In the case of H1N1 influenza epidemics, care services need to be allocated more to patients who have higher age and suffer from myalgia and dyspnea.