Archives of Clinical Infectious Diseases
Volume:14 Issue: 5, Oct 2019

Multidrug-resistant tuberculosis (MDR-TB) is one of the main challenges to TB control, particularly in developing countries such as Iran. Continuous TB drug resistance surveillance is required for the effective management of TB patients.

The antibiotic susceptibility patterns of clinical Mycobacterium tuberculosis isolates were retrospectively analyzed from April 2012 to March 2018. Conventional and molecular methods were used for the identification and drug susceptibility testing (DST) of M. tuberculosis isolates.

A total of 3,012 clinical specimens were collected form TB-suspected patients. Of them, 100 (3.3%) were culture-positive and assigned as M. tuberculosis by phenotypic and molecular methods. According to DST, 17 (17%) isolates were MDR-TB.

Improved diagnosis and treatment of MDR-TB may lead to better control of the disease in Iran.

Helicobacter pylori is a spiral-shaped bacterium that chronically resides in the human gastric epithelium. Helicobacter pylori strains are genetically diverse organisms encoding informative genotypic polymorphisms that can reflect both ancestral and human migrations history.

In this study we aimed to investigate the phylogenetic diversity of Iranian H. pylori isolates by using multi-locus sequence typing (MLST).

A total of 37 H. pylori isolates cultured from biopsy specimens from patients who referred to endoscopy unit at Taleghani Hospital in Tehran during 2015 to 2016 were included in this study. The MLST was performed for all the isolates using seven housekeeping genes, including atpA, efp, mutY, ppa, trpC, ureI and yphC . Phylogenetic analysis was performed using sequence datasets of our H. pylori strains intermingled with MLST datasets of neighboring countries and global populations.

Our results showed that approximately 38% (14/37) of the Iranian H. pylori strains were identical in at least three gene loci, with the ureI gene (48.6%, 18/37) found as the most identical allele. Additionally, the phylogenetic analyses showed that Iranian strains fall into distinct clusters, and were intermingled mostly amongst the hpEurope isolates, including isolates from Turkey, Palestine, Israel, Lebanon, Egypt, Greece, Germany, Netherlands, Spain, UK, Finland, and Italy. The present study revealed that Iranian H. pylori strains are drastically diverse, and are originally comparable to the ancestry of the hpEurope populations.

In conclusion, although similarity of the Iranian H. pylori strains is shown in few gene loci comparable to those mostly find in the hpEurope population, diversity at nucleotide sequences and STs is common among them.

Psseudomonas aerugiona is a major cause of morbidity and mortality among hospitalized patients.

Because of increasing antibiotic resistance, this study investigated the prevalence of blaIMP, blaPER, blaVEB, blaGES, pmrA, pmrB, and mcr-1 genes in P. aeruginosa isolates among burn and CF (Cystic Fibrosis) patients in Tehran.

During 2016 - 2017, 80 and 41 isolates of P. aeruginosa were collected from burn and CF patients, respectively, in Shahid Motahhari and Mofid Children’s hospitals. Based on the CLSI protocol, an antibiotic susceptibility test was performed using the disk diffusion method. Then PCR and further sequencing were used to evaluate the frequency of the above-named genes.

In both groups, high rates of resistance to amikacin, cefepime, imipenem, ciprofloxacin, ceftazidime, aztreonam, piperacillin, gentamycin and piperacillin-tazobactam were detected. Colistin was determined to be the best choice for treatment. In burn patients, the highest frequency was detected for the blaVEB-1 (55%) gene and the frequencies of blaPER-1, blaIMP-1, and blaGES-1 were 27.5%, 25%, and 13.75%, respectively. In CF patients, the blaPER-1 gene was more common (12.19%), and the frequency rates of blaVEB-1 and blaIMP-1 were 2.43% each. The blaGES-1 gene was not detected. Despite the fact that all of the isolates in both groups had pmrA and pmrB genes, different mutations were detected by sequencing. The mcr-1 gene was not shown in all isolates.

Hopefully, by the low frequency of mcr-1 gene and the rate of mutation in pmrAB genes in this study, the rate of resistance can keep low with caution prescription to polymyxins.

Acute kidney injury (AKI) due to antibiotic nephrotoxicity is a complication that can be avoided or managed properly if diagnosed early.

We aimed to determine the incidence and risk factors of AKI and to assess the possible effects of nephrotoxic antibiotic therapy on its development in a large group of patients with infective endocarditis (IE).

Patients with definite or possible IE diagnosed based on the Duke criteria were included in this retrospective cohort study at a tertiary referral center from 2007 to 2017. Data were derived from the single-center Iranian Registry of Infective Endocarditis (IRIE). Baseline risk factors for AKI were assessed via repeated serum creatinine measurements. Patients (n = 22) with end-stage renal failure undergoing dialysis were excluded. AKI was defined and staged in accordance with the Kidney Disease: Improving Global Outcomes (KDIGO) classification.

Totally, 498 patients at a mean age of 45 ± 16 years were studied. The baseline creatinine level was 1.26 ± 0.72 mg/dL. AKI occurred in 126 (26.3%) patients 1 week after the initiation of antibiotic therapy. There was a significant relationship between AKI and the use of gentamicin (P = 0.01) and gentamicin and vancomycin concomitantly (P = 0.01). At the end of the treatment, after dose adjustment and additional treatments, the incidence of AKI decreased to 22.7%, whereas this improvement was less remarkable in the patients with prior renal failure. Some independent variables, including age (P = 0.04), diabetes (P < 0.0001), prior renal failure (creatinine > 2 mg/dL), anemia (P = 0.003), left-sided IE (P = 0.04), and positive blood cultures with Staphylococcus aureus (P = 0.04) had a statistically significant association with AKI.

Close monitoring of the renal function is essential in IE patients receiving treatment with nephrotoxic antibiotics, especially patients with advanced age, diabetes, chronic renal failure, anemia, and left-sided IE.

Toxoplasmosis is one of the common parasitic infections in the human population. It has been estimated that one out of every three persons is infected with this organism. The role of toxoplasmosis has been evaluated in neurological disorders such as migraine, schizophrenia, Parkinson, Alzheimer’s disease and recently, dementia. Dementia has a wide distribution in the elderly.

This study was conducted to determine the possible role of Toxoplasma infection in dementia patients in Arak and Hamadan cities, West of Iran.

In this case-control study, 100 dementia patients referring to hospital settings in Arak and Hamadan and 99 healthy controls were selected under the supervision of neurologists. Their blood samples were transferred to the Research Laboratory of Arak University of Medical Sciences under the cold chain. Serum specimens were isolated and frozen at -20°C until use. T. gondii IgG and IgM were analyzed in serum samples using Enzyme-Linked Immunosorbent assay.

The total prevalence of T. gondii infection among dementia patients and healthy controls were 59% (59/100) and 39.3% (39/99), respectively. A statistically significant difference was observed in the seroprevalence of toxoplasmosis between the case and control groups (P = 0.002). IgG seropositivity was higher among patients from Hamadan than among those from Arak (68% versus 50%). IgM seropositivity was determined in two patients from Arak. There was a significant correlation between the seroprevalence of toxoplasmosis and the presence of cats in their neighborhood and meat consumption.

The possible effect of T. gondii on dementia can lead to significantly higher seropositivity of IgG in dementia individuals than in controls. Control measures are essential to prevent toxoplasmosis, especially in people with dementia.

Urinary tract infection (UTI) is a common disease in hospitalized patients with indwelling devices especially in the intensive care units (ICUs). Candida species are the etiologic agents of 20% - 25% of UTI in ICUs, and the most common organisms after Escherichia coli. Although fungal UTIs are clearly rare in comparison with bacterial UTIs, however there has been an increase in the prevalence of Candida species since 1980s. Despite Candida albicans being a main etiologic agent of fungal UTI, non-albicans Candida species (NACs) such as C. krusei, and C. glabrata, are repeatedly isolated from clinical samples. Identification of Candida to the species level is crucial due to expanding resistance of NACs to the antifungal agents.

The present study aimed to identify the causative agents of fungal UTI among hospitalized patients at the ICU ward of Al-Zahra university hospital in Isfahan, Iran.

From March 2017 to October 2018, 100 ICU patients with positive urine cultures of Candida species were registered in Isfahan, Iran. All clinical isolates were sub-cultured on sabouraud dextrose agar, and CHROMagar Candida media and incubated at 37°C for 48 hours. Molecular identification was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique using specific primers.

Candida albicans was the most prevalent species among clinical isolates (94%) followed by Candida tropicalis (4%), Candida glabrata (1%), and Candida parapsilosis (1%). Most patients belonged to the age range of 71 - 80. Diabetes mellitus and neutropenia were the main risk factors among patients.

Since Candida albicans was the most prevalent species in the present study, and due to its various sensitivities to antifungal agents, antifungal susceptibility testing for clinical isolates is recommended for better management of Candida UTI.

Acinetobacter baumannii has gained attention for years as a significant clinical problem due to the increase of antibiotic-resistant strain. Indeed, A. baumannii OmpA is one of the highly conserved membrane proteins among Gram-negative bacteria that has multiple roles in interacting with the host during infection, thereby representing an effective target for the development of novel antibacterial or vaccination therapies. Nowadays, finding suitable epitope-specific antigens inside the conserved proteins such as OmpA is a promising method for successful vaccination programs. Therefore, in the present study, the coding sequence of the 240 to 356 amino acid residues of A. baumannii OmpA (AbOmpA240-356) was cloned into the vector pET-28a and purified using nickel affinity chromatography. In addition, the anti-His tag antibody is used to validate its production. This system of protein expression and purification may be useful for further characterization of AbOmpA240-356 protein fraction. Therefore, this study can lead to the introduction of suitable candidates for the development of an effective vaccine based on OmpA against this bacterium for further analysis