ABSTRACT

       Background and Objective: Herpes simplex encephalitis is a life-threatening consequence of the central nervous system (CNS) infection with Herpes simplex virus (HSV). Although it is a rare disease, mortality rates reach 70% in the absence of therapy and only a minority of individuals can return to normal function. The aim of this study was to determine possible correlation between HSV infection and the incidence of encephalitis in patients with neurological signs.

        Methods: Overall, 152 CSF samples were tested from patients with neurological signs referred to Mahdieh Clinical Laboratory in Isfahan from 2010 to 2013. After cerebrospinal fluid (CSF) collection, DNA was extracted and real-time polymerase chain reaction (PCR) was performed for HSV detection.

          Results: Of 152 patients tested, 50 were diagnosed with encephalitis. HSV DNA was present in the CSF of 13 patients with encephalitis. HSV was significantly higher (p< 0.05) in patients with encephalitis, which shows the significance of infection as an etiological factor of this disease. About 60% of the encephalitis cases were in age range of 1-24 months.

         Conclusion: According to the findings of the present study, Cesarean section is recommended for HSV-positive mothers. A routine real-time PCR test is suggested for HSV detection in patients with encephalitis to avoid unnecessary antiviral treatments.

       

ABSTRACT
       Background and Objective: Escherichia coli is one of the most common causes of hospital-acquired infections. Extended-spectrum β-lactamase (ESBL)-producing E. coli strains are resistant to third-generation cephalosporins. The three main genes involved in ESBL production are TEM, SHV and CTX-M. Detection of ESBL-producing E. coli is of importance for infection control, reduction of excessive antibiotic use and epidemiological surveillance. This study aimed to detect ESBL-producing E. coli strains isolated from wound infections using phenotypic and molecular methods.
       Methods: During 2013- early 2015, 86 strains were collected from three hospitals in Isfahan, Iran. Antibiotic susceptibility testing was done using ceftazidime and ceftazidime + clavulanic acid discs. Polymerase chain reaction was used for the detection of the three resistance genes.
      Results: The resistance genes SHV, CTX-M and TEM were detected in 49 isolates (56.9%). In addition, 39 isolates (45%) were ESBL-producing strains. According to the results, 5 (5.8%), 14 (16.2%), 19 (22%) and 11 (12.7%) isolates contained the SHV, CTX-M, TEM and CTX-M + TEM genes, respectively. The frequency of CTX and TEM were significantly higher than that of SHV gene (P <0.05). Most of the isolated bacteria were resistant to cefazolin and sensitive to nitrofurantoin.
       Conclusions: There is a difference between the frequency of ESBL-positive isolates reported in the phenotypic and genotypic methods, which could be due to the lower sensitivity of the phenotypic method and impact of environmental factors on the emergence of antibiotic resistance.
       Keywords: Antibiotic resistance genes, ESBL, TEM, SHV, CTX-M, Escherichia coli.

ABSTRACT
          Three major hepatitis B virus (HBV) antigens include HBcAg, HBeAg and HBsAg. HBeAg is the extracellular form of HBcAg, and is seen almost exclusively in people who have circulating serum HBV DNA. Presence of HBsAg in serum indicates that the individual has contracted HBV infection. Chronic hepatitis HBeAg-negative/anti-HBe–positive is known as an important form of chronic hepatitis B in the Mediterranean region. In this report, we used Real-Time PCR and ELISA for detection of HBV and HBeAg/HbsAg, respectively. In our investigation on 4743 HBV cases referred to the Mahdieh Clinical Laboratory between 2008 and 2016, we found a 53-year-old man with clinical symptoms of hepatitis and abnormal molecular and serological features. Despite the presence of clinical symptoms and high viral load (128 × 10⁵ iu/ml), the patient was HBsAg-positive and HBeAg-negative. Identifying this type of HBV could indicate spread of this type of hepatitis in Isfahan, Iran.
           Keywords: Hepatitis B, HbsAg, HBeAg.

ABSTRACT
            Background and Objectives: Pseudomonas aeruginosa is an opportunistic pathogen resistant to various antibiotics. The aim of the present study was to study resistant patterns in clinical isolates of P. aeruginosa, classify them into pandrug resistance (PDR), extensive drug resistance (XDR) and multidrug resistance (MDR) groups, and identify extended-spectrum β-lactamase (ESBL)-positive isolates using the phenotypic and genotypic methods.
            Methods: This cross-sectional study was conducted on 161 P. aeruginosa isolates collected from the city of Isfahan, Iran. Antibiotic susceptibility tests were performed using 11 antimicrobial agents. ESBL-positive strains were identified using the phenotypic and genotypic methods.
            Results: The highest level of antibiotic resistance was observed against ceftazidime (77.64%). None of the isolates was resistant to polymyxin B. In the phenotypic method, 64 isolates (39.75%) were found as ESLB-positive, whereas 132 isolates (81.98%) were ESBL-positive in the genotypic method. The number of ESBL-positive isolates in the genotypic method was significantly higher than in the phenotypic method. The frequency of XDR and MDR isolates was 50.93% and 27.32%, respectively. None of the isolates was PDR. The frequency of the bla_TEM gene was significantly higher than other genes (P<0.0001).
            Conclusion: It was revealed that the genotypic method was much more accurate in identifying ESBL-positive strains than the phenotypic method. Therefore, use of the molecular method may increase the chance of successful treatment with antibiotics of the β-lactam family.
            Keywords: Drug Resistance,  β-lactamases, Pseudomonas aeruginosa.