Probiotics: truths and illusions

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Investigation of Carbapenem-Resistant AcinetobacterBaumannii Resistance Rate in Clinical Specimens of Newborns at Imam Khomeini Hospital in Tehran

Background: Carbapenem-resistant Acinetobacter Baumannii (CRAB) hospital infection poses a serious threat to the health of the newborns in neonatal intensive care units (NICU). The present study was conducted to evaluate the prevalence and resistance of hospital infections in the NICU ward at Imam Khomeini hospital in Tehran.Materials and Methods: The blaOXA-51 like gene was investigated with polymerase chain reaction (PCR). Then, sensitivity of isolates to different antibiotics was assessed using disc diffusion method and broth micro dilutions to determine the minimum inhibitory concentrations (MICs). Pulsed field gel electrophoresis (PFGE) was used for typing of randomly collected CRAB infection at different wards of this hospital. Results: A total of 10 CRAB infections were isolatedduringthe6-month study period, and it was found that 100% of them were positive forblaOXA-51-like gene in PCR assay.  All  isolates were resistant to all tested antibiotics, except colistin, polymyxin B, and tigecycline. CRAB isolates had a high MIC values for imipenem, cefotaxim, and amikacin, showing multidrug resistant (MDR) phenotype. According to PFGE analysis,3palsotypes including clone A (7%), clone B (2%), and clone D (1%) were seen in the 10 CRAB isolates. Clone A was a dominant clone and spread in different wards of the hospital, especially in other ICUs and the emergency ward. Moreover, the similarity between the palsotypes showed the ability of transferring CRAB infection from different wards of the hospital to the NICU.Conclusions: Based on the results of this study, CRAB infection, with a high resistance rate, has the ability to enter into important wards such as NICU, and thus it is highly important to control the presence of these isolates in different parts of the hospital

Therapeutic effects of probiotics and herbal medications on oxalate nephrolithiasis: a mini systematic review

Background and Objectives: The majority of all kidney stone cases are oxalate urolithiasis with a high risk of recurrence. Beside its widespread occurrence, kidney stones are characterized by severe complications and high treatment costs. Probiotics and herbal medications could be forthcoming therapeutic interventions in the management of oxalate kidney stones. Materials and Methods: The PubMed/MEDLINE database was searched for keywords “Oxalobacter formigenes” AND “Oxalate” OR “oxalate degradation” AND “Lactobacillus” OR “Bifidobacterium” OR “recombinant Lactobacillus” OR “Bacillus subtilis”, and “urolithiasis” AND “herbal extract”. The search returned 253 results, 38 of which were included in the review. Results: Most of the oxalate-degrading probiotics belong to the Oxalobacter formigenes, Lactobacillus, Bifidobacterium, and Bacillus genus with a minimum dosage of 107 CFU in the form of capsules, sachets, and lyophilized powder. Oxalate concentration in media was 5-50mM with an incubation time ranging from 24h to 14 days. The majority of the studies suggested that probiotic supplementation might be useful for reducing urinary excretion of oxalate and urea and alleviation of stone formation. Different herbal extracts were used on murine models of nephrolithiasis (induced by 0.5-3% ethylene glycol) with reduction of renal inflammation and urinary parameters, and calcium oxalate crystals. Conclusion: Several strains of probiotics and herbal extracts confer protective effects against kidney stone/nephrolithiasis, indicating their promising nature for being considered as elements of preventive / adjuvant therapeutic strategies

Distribution of ciprofloxacin-resistance genes among ST131 and non-ST131 clones of Escherichia coli isolates with ESBL phenotypes isolated from women with urinary tract infection

Background and Objectives: Escherichia coli (E. coli) sequence type 131 (ST131) is associated with extended-spectrum beta-lactamase (ESBL) production and fluoroquinolone resistance. This study aimed to investigate the prevalence of ST131, ESBL, and plasmid-mediated quinolone resistance (PMQR) genes in the ciprofloxacin-resistant (CIPR) and ESBL producers from women with UTI. Materials and Methods: The CIP-resistant ESBL producing (CIPR/ESBL+) E. coli isolates were screened for ST131-by specific PCR of mdh and gyrB. The ESBL and PMQR genes were screened by single PCR. The ST131 and non-ST131 isolates were selected to determine the mutations of gyrA and parC using PCR and sequencing, and also their genetic background by the Pasteur-MLST scheme. Results: Overall, 55% (33/60) CIPR/ESBL+ isolates were identified as ST131 (94% O25b-ST131). Resistance rate to ampicillin-sulbactam (70%), aztreonam (97%) and gentamicin (61%), the prevalence of aac(6′)-Ib-cr (66%), blaCTX-M-15 (82%), the profile of qnrS+aac(6′)-Ib-cr (30%), and the double mutation in the parC was significantly higher in ST131 than non-ST131 isolates. The coexistence of PMQR and ESBL genes was found in more than 50% of ST131 and non-ST131 isolates. ST131 isolates differentiated into PST43 and PST506. Conclusion: Management of women with UTI caused by the CIPR/ESBL+ isolates (ST131) co-harbored PMQR, ESBL, and chromosomal mutations, is important for their effective therapy

Cloning of the Recombinant Cytochrome P450 Cyp141 Protein of Mycobacterium tuberculosis as a Diagnostic Target and Vaccine Candidate

Background: Tuberculosis has been announced as a global emergency by World Health Organization and the second infectious agent of mortality worldwide. The general policy in the development of new vaccines is to develop some vaccines with higher efficiency not only for infants but also for adults compared with the Bacillus Calmette-Guerin vaccine. Recently, cytochrome P450 cyp141 has been introduced as a new target for detecting Mycobacterium tuberculosis from clinical samples. Objectives: The aim of this study was to clone this gene in order to pave the way for more evaluation. Materials and Methods: M. tuberculosis H37Rv DNA was extracted by a standard phenol-chlorophorm protocol. After designing the specific primers, P450 cyp141 gene was replicated by PCR. The purified PCR products were then subcloned into the pTZ57R/T plasmid vector. After extraction, enzyme digestion, and recombinant pTZ57R/T-cyp141 plasmid vector sequencing, the aforementioned products were cloned into a pET-26b plasmid vector. Then, the recombinant pET26b-cyp141 plasmid molecules were transformed to Escherichia coli strain BL21 (DE3) using the transformation method. Next, the recombinant pET26b-cyp141 plasmids were purified and evaluated by the enzyme digestion analysis. Results: The cloning of P450 cyp141 gene was confirmed by the enzyme digestion and sequencing of the recombinant pTZ57R/T-cyp141 and pET26b-cyp141 plasmid vectors. Conclusions: The results of this study demonstrated that the P450 cyp141 gene was successfully cloned into a pET26b plasmid vector as an expression vector. In this paper, for the first time in Iran, this gene was cloned for more purposes, including the expression and purification of the recombinant cytochrome P450 cyp141 protein

Anti-microbial Resistance Pattern of Uropathogens Isolated from Hospitalized Patients in Imam Khomeini hospital, Tehran, Iran

Background: Urinary tract infection (UTI) is one of the most common type of bacterial infectious diseases which occurs in all age groups. The aim of this study was to determine anti-microbial resistance pattern of bacterial pathogens causing UTIs in hospitalized patients at the Imam Khomeini Hospital, Tehran, Iran.Material and Methods: Urine samples were collected from 11157 hospitalized patients at different wards of Imam Khomeini Hospital in Tehran, between January 2015 and December 2015.The cultured plates were assessed for significant bacterial growth. Anti-microbial susceptibility test was performed using standard disk diffusion method.Results: Out of the 11157 collected urine samples, significant bacterial growth of 25.38% was observed. The most common cause of UTI was gram-negative bacteria (82.2%). More than 50% of the gram-negative bacteria were resistant to ceftriaxone, ceftazidime and trimethoprim-sulfamethoxazole. Enterococcus spp. (10.1%) was found as the third causative agent of UTIs and the most common gram-positive bacteria.Conclusion: we conclude that the examination of the most common etiological agent of UTIs and their antimicrobial resistance patterns is advantageous and necessary in order to design a guideline for empirical therapy

Specific immune responses induced by multi-epitope DNA derived from Mycobacterium tuberculosis DosR antigens

One third of the world population are latently infected with Mycobacterium tuberculosis and are at the risk of reactivation of tuberculosis (TB). The most effective strategy for control of TB worldwide is the development of a vaccine that inhibits progression of latent TB to active infection. In this study, two optimized constructs consisting of multi-epitopes DNA derived from three latency antigens Rv2029c, Rv2031c, and Rv2627c fused with or without light chain 3 (LC3) are synthetized. The immunogenicity effectiveness of two DNA constructs was evaluated in the mouse model. LC3-fused multi-epitope DNA construct induced strong specific Th1 immune responses with high increase in IFN-γ+ CD4+ and IL-2+ CD4+ T cell populations (both with p + IL-2+ CD4+ T cell population (p + CD8+ T cell population (p + and CD8+ T cell populations. The results indicated that LC3-fused multi-epitope DNA construct has a potential to be investigated for future development of a new TB vaccine

Detection of Nocardia, Streptomyces and Rhodococcus from bronchoalveolar lavage specimens of patients with HIV by Multiplex PCR Assay

Background: Nocardia, Streptomyces and Rhodococcus are life threatening opportunistic pathogens under immunodeficiency conditions, particularly among patients infected with HIV. Rapid and accurate detection of these infections can improve immune health quality, patient management and appropriate treatment. The aim of this study was to design a novel multiplex-PCR assay for rapid diagnosis of these three organisms directly from bronchoalveolar lavage (BAL) specimens of patients infected with HIV.Methods: The genus specific primers were designed for directdetection of Nocardia, Streptomyces and Rhodococcus in a single tube multiplex PCR. This PCR specifically amplified the target genes from pure cultures. It subsequently was applied on BAL specimens of 29 HIV positive patients that had previously been culture negative for actinomycete bacteria, of which Nocardia, Streptomyces and Rhodococcus are members.Results: Of 29 respiratory clinical specimens, there were positive for Nocardia spp. and one was positive for Streptomyces spp using the multiplex PCR assay. The sequencing of the PCR products identified the species as Nocardia cyriacigeorgica (n=2), Nocardia farcinica and Streptomyces albus.Conclusion: This novel multiplex PCR assay yielded reliable results for accurate identification of Nocardia, Streptomyces and Rhodococcus from BAL while the results of bacterial culture were negative.