Jundishapur Journal of Microbiology
Volume:13 Issue: 2, Feb 2020

Rotavirus has been considered the main causal agent of gastroenteritis worldwide. However, after rotavirus vaccine implementation, new reports have revealed the prevalence of other viral gastroenteritis agents such as norovirus, adenovirus, astrovirus, and other rare rotaviruses. Their prevalence is increasing in both developed and developing countries and may become a serious public health problem.

The study aimed to determine the relationship between co-infections with enteric viruses and acute gastroenteritis in hospitalized children under five years of age.

A total of 57 stool samples were collected during 2010 - 2011 in two hospitals in Chihuahua, México, located in northern Mexico. The genotypic analysis was done using RT-PCR of specific regions of the viral enteric genome. In addition, phylogenetic analysis was developed by sequencing of the complete genome characteristic for the classification of enteric viruses by the neighbor-joining method.

Molecular detection revealed the presence of at least one viral agent in 61.4% (n = 35) of the total analyzed samples. Among the positive samples, rotavirus was identified in 49.12% (n = 21), adenovirus in 14% (n = 8), and a co-infection of norovirus and astrovirus in 3.5% (n = 2) of the samples. Rotavirus co-infection with another viral agent was identified in 14.28% (n = 5) of positive samples.

Viral gastroenteritis has been decreasing after the introduction of the rotavirus vaccine. However, the appearance of co-infections has significantly increased, as evidenced by the high prevalence of enteroviruses among hospitalized children in Chihuahua, Mexico.

 Pseudomonas aeruginosa is an opportunistic pathogen that causing high morbidity and mortality, and responsible for a high proportion of hospital infections. Recently, P. aeruginosa infections having carbapenem group antibiotic-resistant have been increasing and serious problems are being experienced in treatment. Carbapenem resistance mechanisms are the loss of OprD porin protein, excretion of drug with the efflux system and production of metallo-beta-lactamase (MBL).

 The aim of this study was to investigate the production of MBL in carbapenem resistant P. aeruginosa isolates phenotypically and genotypically. Study design: In this study, 58 P. aeruginosa isolates were included from various clinical samples between May 2014 and March 2015 at the Microbiology Laboratory of Tertiary Care Hospital of Mersin University, Faculty of Medicine.

 The strains were identified by automated system (Vitek 2, BioMerieux, France); and antibiotic susceptibilities were performed by using the disc diffusion method and the automated system (Vitek 2). Gradient test was performed for imipenem (IPM) and meropenem (MEM) to confirm the carbapenem resistance. Combined disc test (CDT) and MBL E-test were used for the detection of MLB phenotypically. The most common MBL genes, blaIMP-1, blaIMP-2, blaVIM1, blaVIM-2, blaSPM, blaGIM-1 were investigated with polymerase chain reaction (PCR). Direct DNA sequence analysis was performed to PCR positive isolates.

 Of the 58 isolates, 57 (99%) were found resistant to IPM, 43 (74%) to MEM, one was intermediate susceptible to IPM and 15 (25%) to MEM by automated system. Of the 58 isolates, 57 were found to be resistant and one was intermediate susceptible to IPM, 34 isolate were found to be resistant, 17 were intermediate susceptible and 7 were susceptible to MEM by gradient test. MBL positivity was detected on 37 (63.7%) isolates by CDT and 16 (27%) by E-test. MBL gene region was detected on 8 isolates (13.7%) by PCR and 6 isolates were found to be VIM-1 gene region positive and 2 isolates were GIM-1 gene region positive. This study is the first study showing the GIM-1 gene in P. aeruginosa in Turkey. DNA sequence analysis data was compared with the reference NCBI sequence data in the PubMed-BLAST program to confirm gene regions.

 Phenotypic tests can be used as screening test for the detection of MBL activity in carbapenem resistant P. aeruginosa isolates. However, confirmation of the results by molecular tests and determination of the gene regions responsible for resistance are very important epidemiologically.

 Shiga-toxigenic Escherichia coli (STEC) is an important foodborne pathogen and considered a worldwide problem. The infection can cause severe illnesses, including hemolytic uremic syndrome. Traditional methods for STEC detection are currently not done in clinical laboratories due to the cost and related long turnaround time, which necessitates the development of quick and reliable alternative detection methods.

 In this study, the application of PCR and real-time PCR methods for rapid detection of STEC in DNA extracts of stool samples was investigated.

 A synthetic control DNA vector, containing target genes of stx1, stx2, EhxA, and eae, was designed to evaluate the validity of these methods. Moreover, efficiency of primers targeting the genes, limit of detection, repeatability, sensitivity, and specificity of real-time PCR assay was compared with PCR results.

 Repeatability of real-time PCR assay showed percent coefficient of variation of 3.3% - 16.1% and sensitivity of 66% to 100%. Efficiency of all the primers was 100% with a detection limit of 103 copies of DNA per reaction for both of the two assays. Comparison of the results showed that real-time PCR was more sensitive than conventional PCR. The chimeric vector interfered with template DNA when it was used as an internal control in PCR and real-time PCR assays; however, its application as external control was approved for detection of all targeted genes in STEC.

 These results confirmed application of the chimeric vector as an external control in detection of STEC by both PCR and real-time PCR assays, but its usage as an internal control was not approved in this study.

Human enteroviruses (HEVs) cause various infections, especially in children. These viruses are common causes of aseptic meningitis worldwide.

Limited information about HEV-related aseptic meningitis is available in Isfahan/Iran. Therefore, this study was designed to evaluate HEV-related meningitis in this city.

In this cross-sectional study, 70 patients with the diagnosis of aseptic meningitis were enrolled and divided into 2 groups, including children and adults, in 2 centers of Alzahra and Imam Hossein hospitals from December 2016 to December 2017. Diagnosis of meningitis was made on clinical symptoms and lumbar puncture samples. The RNA of HEV was extracted with Roch extraction Kit and enteroviral infection was detected by real-time PCR test. Chi-square and descriptive statistics were used for data analysis.

Enteroviruses were detected in 2 cases out of 70 patients (2.8%). Two cases were in the children group (9.5%). The relationship between gender and prevalence was not significant. Two cases were found in summer and winter.

We found that the positive test results of enterovirus in lumbar puncture (LP) samples were significant in the children patients (9.5%, P value = 0.026) but the positive test results in adult patients were zero. So it makes sense to do PCR tests in children with signs or symptoms of meningitis. A well-designed study with more samples is recommended for better evaluation of HEV-related infections, especially aseptic meningitis in Iran. These types of studies help to find a good strategy for the management of HEV infections in Iran and, thereby reducing hospitalization and overuse of antibiotics.

 Hepatitis B virus (HBV) and hepatitis D virus (HDV) infections are known as major health concerns world-wide. Nucleoside analogs (NAs) are widely used in anti-HBV therapy. However, HBV resistance to Nas may result in disease recurrence.

 The present study aimed to evaluate the prevalence of HBV and HDV infections, and to investigate the presence of YMDD motif in HBV-infected patients.

 In this cross-sectional study, a total of 1600 blood specimens were collected from HBV-suspected patients, who referred to diagnostic centers in Qom Province, Iran from July 2018 to March 2019 before and after lamivudine therapy. The presence of HBV in the specimens was investigated using ELISA and nested PCR assays. Also, HDV and YMDD motif were detected in HBV-infected patients using the PCR technique. In order to confirm the presence of HDAg gene of HDV, the PCR products of some HBV/HDV-positive specimens were subjected to direct sequencing.

 The number of HBsAg positive patients was 180 (11.25%) (P < 0.05) according to ELISA and nested PCR assays; these patients were in the age range of 32 - 38 years. Also, 11 (6.1%) patients were infected with HBV/HDV. The frequency of lamivudine resistance mutation in the YMDD region was 28 (15.5%) among chronic HBV patients. The constructed phylogenetic trees for HDAg gene of HDV showed that most HBV/HDV isolates had similar sequences to the Iranian isolates.

 The present results showed that it is important to increase our knowledge about the frequency of chronic HBV and HDV infections. Also, development of new antiviral medications is important for prevention and prompt and appropriate treatment.

 Among different factors, middle ear infections are the most common causes of referral to an otolaryngologist. Currently, ciprofloxacin drops are an effective treatment for middle ear infections.

 The purpose of this study was to compare the therapeutic effects of ciprofloxacin drops and powder in chronic bacterial middle ear infections.

 The present randomized clinical trial was conducted at Ayatollah Rouhani Hospital in Babol, Iran. After suction clearance, the patients were randomly divided into two groups: the control group received ciprofloxacin drops and the case group received ciprofloxacin powder in the tympanic cavity. All patients were evaluated for improvement of symptoms after two weeks.

 Of the 125 patients, 60 (48%) had bacterial infection. There were 30 patients in the control and the case groups equally. Ear manipulation results showed that only 16.67% of the subjects had ear manipulation in the drop group, while that was 43.33% in the powder group. The frequency of itching, swelling and discharge was not significantly different between the two groups before the treatment, but this difference was significant after the treatment, especially in pain, swelling, and discharge. Overall, Pseudomonas aeruginosa, Enterobacteriaceae spp. and Staphylococcus epidermidis were the most common bacteria grown in culture.

 Owing to the better and more effective impact of ciprofloxacin drops than ciprofloxacin powder in improving the symptoms of patients, the use of ciprofloxacin powder is not recommended as a treatment for chronic bacterial infection of the middle ear.