The role of altered microRNA expression in premalignant and malignant head and neck lesions with epithelial origin.

Background and Aims: The premalignant lesions of the oral cavity carry a risk of transformation to malignancy. Hence, early diagnosis followed by timely intervention remarkably affects the prognosis of patients. During tumorigenesis, particular microRNAs (miRNAs) show altered expressions and because of their post transcriptionally regulatory role could provide favorable diagnostic, therapeutic, or prognostic values in head and neck cancers. Methods: In this review, we have demonstrated diagnostic, prognostic, and potential therapeutic roles of some miRNAs associated with oral premalignant and malignant lesions based on previous validate studies. Results: It is previously documented that dysregulation of miRNAs contributes to cancer development and progression. MiRNAs could be tumor suppressors that normally suppress cell proliferation, differentiation, and apoptosis or play as oncogenes that improved tumorigenesis process. Altered expression of miRNAs has also been reported in premalignant oral epithelial lesions such as leukoplakia, oral submucous fibrosis, oral lichen planus and some malignant carcinoma like oral squamous cell, verrucous, spindle cell, Merkel cell carcinoma and basal cell. Conclusion: Some of miRNAs could be new therapeutic candidates in miRNA-based target gene therapy. Although more investigations are required to identify the most favorable miRNA candidate, altered expression of some miRNAs could be used as biomarkers in premalignant lesions and oral cancers with high sensitivity and specificity.

Seroprevalence of Hepatitis A and Hepatitis E Viruses among Pregnant Women in Northern Iran.

Background: Hepatitis A (HAV) and hepatitis E viruses (HEV) are endemic in Iran and are known major causes of acute viral hepatitis. Also, during pregnancy, they are associated with severe outcomes. Therefore, it is vital to evaluate the antibody levels against HAV and HEV in pregnant women to avoid severe outcomes incidence. Study design and methods. A total of 247 pregnant women were enrolled in this prospective cross-sectional study. In addition to completing the questionnaire and interviewing all participants, the serum samples were tested for anti-HAV and anti-HEV IgG using the enzyme-linked immunosorbent assay (ELISA). The association between anti-HAV and anti-HEV antibodies status and risk factors was evaluated. Results: The mean age of patients was 28.06 ± 5.29 years. Anti-HAV antibody was found in 111 patients (44.9%), while anti-HEV antibody was detected in only two pregnant women (0.8%). The seroprevalence of HAV was inversely related to the level of education. There was no significant correlation between HAV antibody levels and age, marital status, residence location, and pregnancy trimesters. Conclusion: Considering many complications of these diseases in pregnancy, the detection of enteroviral hepatitis, especially HAV in pregnant women, is necessary, and therefore, proactive measures, such as promoting education, improving people awareness, and vaccination, are recommended.

Integron and its role in antimicrobial resistance: A literature review on some bacterial pathogens.

In recent years, different acquired resistance mechanisms, including transposons, bacteriophages, plasmids, and integrons have been identified as involved in the spread of resistance genes in bacteria. The role of integrons as mobile genetic elements playing a central role in antibiotic resistance has been well studied and documented. Integrons are the ancient structures that mediate the evolution of bacteria by acquiring, storing, disposing, and resorting to the reading frameworks in gene cassettes. The term integron describes a large family of genetic elements, all of which are able to capture gene cassettes. Integrons were classified into three important classes based on integrase intI gene sequence. Integrons can carry and spread the antibiotic resistance genes among bacteria and are among the most significant routes of distribution of resistance genes via horizontal transfer. All integrons have three essential core features. The first feature is intI, the second one is an integron-associated recombination site, attI, and an integron-associated promoter, Pc, is the last feature. Among them, the class 1 integron is a major player in the dissemination of antibiotic resistance genes across pathogens and commensals. Various classes of integrons possessing a wide variety of gene cassettes are distributed in bacteria throughout the world. This review thus focuses on the distribution of integrons among important bacteria.

Class I integrons among multidrug resistant Enterobacter spp. isolates from hospitalized patients in Babol, North of Iran.

BACKGROUND: Multidrug resistance (MDR) in Enterobacter spp. has created therapeutic challenges all over the world. The present study was conducted for evaluating the prevalence of class I integron, determining the gene cassettes and antimicrobial resistance profile of Enterobacter spp. isolates from clinical samples in Babol, North of Iran. METHODS: During a 13-month period, 30 Enterobacter spp. isolates were collected from Ayatollah Rouhani Hospital, Babol, Iran. Various types of antimicrobial agents were used to determine the resistance pattern. Class I integron and associated gene cassettes were detected by PCR assay. RESULTS: The resistance rates to AP, CPM, CTX, TM, NI, IMI, AK, CIP and GM antimicrobials were 100%, 93.3%, 33.3%, 33.3%, 30%, 20%, 20%, 20% and 13.3%, respectively. The distribution results of int genes showed that 63.3% of isolates carried the intI genes. Also, the prevalence of aadB, dfrA1, bla OXA30 and bla PSE1 genes were estimated at 36.6%%, 33.3%, 6.6% and 0%, respectively. CONCLUSION: Our results showed that class I integrons have a widespread distribution among the Enterobacter spp. isolates and have clinical relevance to MDR isolates. The results confirmed the necessity for uninterrupted monitoring to prevent distribution of multidrug resistance among Enterobacter spp. strains in Iran.

Neonatal sepsis in Iran: A systematic review and meta-analysis on national prevalence and causative pathogens.

BACKGROUND: Neonatal sepsis is accounted for 30-50% of annual neonatal deaths in developing countries. We performed a systematic review and meta-analysis study to evaluate the national prevalence and identification of the etiological pathogens of neonatal sepsis in Iran. METHODS: A comprehensive literature search was done on the national and international databases for studies published between 2000 and 2019. The DerSimonian and Laird random-effects model was used to calculate pooled prevalence estimates, with 95% confidence intervals (CIs). Subgroup analyses and meta-regressions regarding the gender, type of sepsis and time during were also performed. Data were extracted, analyzed, and presented according to PRISMA guideline. RESULTS: Of 944 publications identified, 22 studies containing 14,683 neonates met the eligibility criteria. The pooled national prevalence of sepsis in Iran was 15.98% (95%CI, 11.96-20.46%; 1,367/14,683). Prevalence rate in boys (20.42%; 95%CI, 9.03-34.8%) was slightly higher than girls (18.5%; 95%CI, 7.4-32.8). A decreasing trend in prevalence of neonatal sepsis was found in recent years, although not statistically significant (c = -0.005; P value = 0.4). The most prevalent causative bacterial pathogens were Enterobacter spp. (23.04%), followed by Klebsiella pneumoniae (17.54%), coagulase-negative Staphylococci (14.06%), Escherichia coli (13.92%), Pseudomonas aeruginosa (12.67%), and Staphylococcus aureus (11.48%). CONCLUSION: Our findings showed a high prevalence of neonatal sepsis in suspected neonates, suggesting the need to implement preventive measures, routine assessment, and close monitoring of neonates. Also, Enterobacter spp. and Klebsiella pneumoniae were identified as the principal bacterial pathogens responsible for neonatal septicemia in Iran.

Helicobacter pylori infection in children: an overview of diagnostic methods.

Children differ from adults regarding Helicobacter pylori (H. pylori) infection in many terms. H. pylori infection represents a key factor in the pathogenesis of duodenal ulcer and chronic gastritis in children. H. pylori infection causes some extraintestinal diseases as well as gastrointestinal diseases. Although, among these illnesses in children, symptoms like recurrent abdominal pain are not specific. Moreover, the role of the pathogen in the growth faltering, iron deficiency anemia, and asthma still remains controversial. A reliable method to detect H. pylori infection is a crucial issue, sand is still a matter of active debate. The tests applied for H. pylori diagnosis are grouped as either invasive or non-invasive methods. Invasive methods consist of endoscopic evaluation, the rapid urease test (RUT), histology, and bacterial culture. Non-invasive tests include the urea breath test (UBT), stool antigen test (SAT), serology, and molecular diagnostic approaches. Use of endoscopy is a pre-requisite for all invasive methods and poses difficulties in children as it is a difficult procedure and requires patient's cooperation. For this reason, the non-invasive tests have been commonly used in children, although their accuracy is not very reliable in some cases. Invasive tests may be opted to confirm the diagnosis as and when needed. This review presents the diagnostic tests used to detect H. pylori infection in children.

Influenza Vaccination and Guillain-Barré Syndrome: Reality or Fear.

Guillain-Barré syndrome (GBS) is an inflammatory disorder and an acute immune-mediated demyelinating neuropathy that causes reduced signal transmissions, progressive muscle weakness, and paralysis. The etiology of the syndrome still remains controversial and uncertain. GBS can be initiated and triggered by respiratory tract infections such as influenza, and intestinal infections such as Campylobacter jejuni. In addition, there is considerable evidence suggesting links between influenza vaccination and GBS. As reported previously, the incidence of GBS in individuals receiving swine flu vaccine was about one to two cases per million. Despite the influenza vaccine efficacy, its association with an immune-mediated demyelinating process can be challenging as millions of people get vaccinated every year. In this review we will discuss the association between influenza infection and vaccination with GBS by focusing on the possible immunopathological mechanisms.

The global and regional prevalence, burden, and risk factors for methicillin-resistant Staphylococcus aureus colonization in HIV-infected people: A systematic review and meta-analysis.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is among the most important opportunistic pathogens in HIV+ patients, resulting in considerable morbidity and mortality. METHODS: The MEDLINE, Scopus, Web of Science, and EMBASE databases were comprehensively searched for studies that investigated the prevalence of MRSA colonization in HIV+ patients. We used a random effects model to calculate pooled prevalence estimates with 95% confidence intervals (CI) and analyzed data based on World Health Organization regions. RESULTS: Among 9,772 records identified, 69 were included in the meta-analysis, comprising 30,050 HIV+ patients from 21 countries. We estimated the pooled worldwide prevalence of MRSA in people living with HIV to be 7% (95% CI 5%-9%, 1,623/30,050), with the highest prevalence in Southeast Asia (16%, 95% CI 9%-24%) and the region of the Americas (10%; 95% CI 7%-13%) and lowest prevalence in the European region (1%; 95% CI 0%-1%). Globally, we estimated approximately 2,659,000 (95% CI 1,835,000-3,303,000) HIV+ patients with colonized MRSA. Potential risk factors for MRSA colonization in HIV+ patients included previous MRSA infection (OR, 7.5; 95% CI, 3.91-14.37), hospitalization in the past year (OR, 1.87; 95% CI 1.11-3.16), and use of antibiotics (OR, 2.52; 95% CI 1.39-4.58). CONCLUSIONS: Our findings emphasize the importance of routine screening for MRSA among all HIV+ patients throughout the world, especially in regions that have a high burden of disease.

Diagnostic methods for Helicobacter pylori infection: ideals, options, and limitations.

Helicobacter pylori (H. pylori) resides in the stomach, colonizes gastric epithelium, and causes several digestive system diseases. Several diagnostic methods utilizing invasive or non-invasive techniques with varying levels of sensitivity and specificity are developed to detect H. pylori infection. Selection of one or more diagnostic tests will depend on the clinical conditions, the experience of the clinician, cost, sensitivity, and specificity. Invasive methods require endoscopy with biopsies of gastric tissues for the histology, culture, and rapid urease test. Among non-invasive tests, urea breath test and fecal antigen tests are a quick diagnostic procedure with comparable accuracy to biopsy-based techniques and are methods of choice in the test and treatment setting. Other techniques such as serological methods to detect immunoglobulin G antibodies to H. pylori can show high accuracy as other non-invasive and invasive biopsies, but do not differentiate between current or past H. pylori infections. Polymerase chain reaction (PCR) is an emerging option that can be categorized as invasive and non-invasive tests. PCR method is beneficial to detect H. pylori from gastric biopsies without the need for the cultures. There is no other chronic gastrointestinal infection such as H. pylori with a set of comparable diagnostic methodologies. Despite the availability of multiple diagnostic methods, it remains unclear on the choice of any one method as the gold standard for detecting H. pylori infection, especially in epidemiological studies. In this work, we review the principal diagnostic methods used to detect H. pylori infection and their advantages and disadvantages, and applications in clinical practice.

The significance role of regulatory T cells in the persistence of infections by intracellular bacteria.

Regulatory T cells (Treg cells), are considered as effective immune cells playing a key role in immune response during cancers, autoimmune and infectious diseases. Regulatory T lymphocytes are divided into two main subgroups: natural Treg cells that generated during maturation in the thymus and have the suppressive activity that is critical for the establishment and maintenance of homeostasis in the body and induced Treg cells (iTreg) that are originated from naive T cells following the self-antigen recognition. In recent years, the roles of Treg in immune responses to microbial infections have received increased attention in researches. Several reports suggested the pivotal role of Treg cells in controlling responses to bacterial infections and demonstrated the impact of regulatory cells on one or more stages in the pathogenesis of bacterial infections. In this review, we describe the significance of regulatory T cells in the immunopathology of bacterial infections by focusing on specific bacterial infections including Mycobacteria, Listeria monocytogenes, and Bordetella pertussis. Moreover, suppressive mechanisms of regulatory T cells during bacterial infection including cell-cell contact, local secretion of inhibitory cytokines and local competition for growth factors will be discussed.

Molecular characterization of Staphylococcus aureus strains isolated among hospital staff nasal carriers of Babol, Iran.

BACKGROUND: Staphylococcus aureus (s. aureus) nasal carriers, particularly the healthcare staff can be considered as a potential source for the spread of resistant strains. The aim of this study was to determine the molecular characterization of S. aureus strains isolated among the staff nasal carriers in one of the teaching hospitals in Babol. METHODS: A total of 120 nasal swabs were taken from the staff of Ayatollah Rouhani Hospital Babol during 2016. The antibiotic resistance pattern was performed by disc diffusion method for 13 antibiotics, including cefoxitin, cephalothin, teicoplanin, vancomycin, daptomycin, oxacillin, amoxicillin, amikacin, linezolid, ciprofloxacin, levofloxacin, erythromycin, rifampin, according to the CLSI 2015. Polymerase chain reaction (PCR) was used to detect mecA and pvl genes. Finally, the different SCCmec types were determined by multiplex- PCR method. RESULTS: Among the 120 collected specimens, 40(33.3%) S. aureus isolates were approved. 28(70%) of strains were identified as methicillin-resistant Staphylococcus aureus (MRSA) and the frequency of pvl gene was confirmed 2(5%). Based on the multiplex PCR assay, four different SCCmec types were detected as 35.7% type I, 14.2% type III, 7.1% type II and 3.5% type IV. By a disc diffusion method, no resistance pattern was observed to vancomycin, while 100% of strains were resistant to amoxicillin. CONCLUSION: Consequently our results illustrated that isolated S. aureus strains among the staff nasal carriers via mentioned molecular characterization may lead to increase the nosocomial persistent infections in hospitalized patients and also health care workers.