Epidemiological burden of Listeria monocytogenes in Iran

Objective(s): Listeria monocytogenes is a foodborne pathogenic bacteria causing the infection listeriosis, which possibly affects all people, particularly immunocompromised persons and pregnant women. This microorganism can be found in several processed foods, dairy products, raw milk, meat and fish products, seafoods, eggs, fruits, and vegetables. This review discusses about the epidemiological significance, incidence, contamination routes of L. monocytogenes in different products and current data about listeriosis in the Iran. Materials and Methods: For accessing to relevant articles and studies, a search was done in main databases and also, almost all Iranian published articles were studied in this field. Results: Outbreaks of listeriosis have been reported in many parts of the worldwide, however there is scanty data about the prevalence of listeriosis in Iran. Accordingly, as a result of high incidence of L. monocytogenes in women with bad obstetric history or history of abortions, diagnosis procedures for detection of L. monocytogenes and timely treatment was suggested. Conclusion: In spite of low incidence of infection in the past, increased interest for lightly preserved and/or ready-to-eat (RTE) food products has recently led to increasing of L. monocytogenes prevalence which has become a public health concern. Subsequently, further researches about the prevalence of L. monocytogenes and also antibiotic susceptibility testing is needed to enable the detection of the contaminated foods, as well as ensures the effective treatment. © 2018, Mashhad University of Medical Sciences. All rights reserved

High prevalence of fluoroquinolone-resistant Escherichia coli strains isolated from urine clinical samples

Background. Fluoroquinolone resistant Escherichia coli isolates have become an important challenge in healthcare settings in Iran. In this study, we have determined Fluoroquinolone resistant E. coli isolates (from both outpatients and inpatients) and evaluated mutations of gyrA and parC within the quinolone resistancedetermining regions (QRDR) of these clinical isolates. Materials and methods. Clinical isolates were recovered from the urine sample of patients with urinary tract infections admitted at Alzahra hospital, Iran, between September and February 2013. We assessed antimicrobial susceptibility of all isolates and determined mutations in QRDR of gyrA and parC genes from 13 fluoroquinolone-resistant isolates by DNA sequencing. Results. A total of 135 E. coli strains were obtained from 135 patients (91 outpatients and 44 inpatients). The resistance rate of fluoroquinolones (Ciprofloxacin, Norfloxacin and Ofloxacin) among our strains was 45.2. Two E. coli isolates were shown just a single mutation, but other isolates possessed 2-5 mutations in gyrA and parC genes. Mutations in the QRDR regions of gyrA were at positions Ser83 and Asp87 and parC at positions Ser80, Glu84, Gly78. Conclusions. Ciprofloxacin is the most common antimicrobial agent used for treating urinary tract infections (UTIs) in healthcare settings in Iran. Accumulation of different substitutions in the QRDR regions of gyrA and parC confers high-level resistance of fluoroquinolones in clinical isolates. © 2019 Pacini Editore SPA. All rights reserved

Isolation of probiotic bacteria from raw camel's milk and their antagonistic effects on two bacteria causing food poisoning

Lactic acid bacteria (LAB) is one of the main classes of acid-producing organisms in the food industry, and they play a vital part in many food and feed fermentations. We isolated and performed molecular identification of LAB from raw camel's milk and assessed their protective effects against pathogenicity induced by Staphylococcus aureus and Escherichia coli. Fourteen samples of camel's milk were obtained from several districts under aseptic conditions. Bacteria isolation was performed by plating the samples on selective media. Isolates were identified by amplification of the 16S ribosomal RNA by PCR and sequencing. A total of 32 isolates were randomly picked, eight of which were analysed in this study. On the basis of phenotypic and genotypic methods, isolated LAB was included Leuconostoc mesenteroides, Lactobacillus plantarum, Weissella paramesenteroides and Weissella confuse. Antagonistic activity of isolated LAB against two pathogenic bacteria showed that they had more inhibitory activity against S. aureus subsp. aureus PTCC 1431 than E. coli ATCC 25922. This study discovered that raw camel's milk obtained from three districts of Kerman province contain LAB bacteria that have antagonistic properties on S. aureus. © 2018 The Author

Link between single nucleotide polymorphism of rs266729 and rs2241766 in the ADIPOQ gene and gestational diabetes in an Iranian population

Background: The manuscript investigates the association between adiponectin gene (ADIPOQ) polymorphisms and gestational diabetes mellitus (GDM) in an Iranian population. Methods: We designed a case-control study involving 265 normal glucose tolerant (NGT) women and 297 GDM patients. Three adiponectin single-nucleotide polymorphisms (rs1501299, rs266729 and rs2241766) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and the protein level was measured by the enzyme-linked immunosorbent assay. Other biochemical parameters were assessed by conventional laboratory methods. Results: We found that rs266729 and rs2241766 were significantly associated with GDM. The genotypes analysis indicated that for rs266729, 51(61.4) of the 83 GDM patients had GG genotype, and 32(38.6) GC/CC genotype and for rs2241766, 75(58.6) of the 128 GDM patients had TT genotype, and 53(41.4) GG/GT genotype. The relation between other single-nucleotide polymorphisms (rs1501299) and GDM was not observed. Conclusion: The ADIPOQ genetic polymorphisms were associated with GDM in our studied population. © 201

Prevalence and antimicrobial susceptibility pattern of toxigenic clostridium difficistrains isolated in iran

Background/aim: Clostridium difficile is a frequent cause of nosocomial infections and has become a major public health concern in developed nations. In the present study, the prevalence and antimicrobial susceptibility pattern of toxigenic C. difficile strains isolated in Iran were investigated. Materials and methods: Between June 2016 and May 2017, 2947 inpatient fecal samples were taken from symptomatic adult hospitalized patients in different units of 32 care facilities in Tehran, Iran. C. difficile strains were identified by microbiological/biochemical methods. Susceptibility to 20 antimicrobials was measured by E-test method. Toxin-specific immunoassays and cytotoxicity assays were used to determine in vitro toxin production. Results: Out of 2947 fecal samples, 538 (18.25) C. difficile isolates were obtained among those with suspected CDI. In E-test method, all C. difficile isolates were susceptible to fidaxomicin, vancomycin, amoxicillin/clavulanate, and meropenem and were resistant to penicillin G. The prevalence of multidrug resistant C. difficile was 69.33 (373/538). Among 538 C. difficile, 147 (27.32), 169 (31.41), and 222 (41.26) isolates were TcdA+/TcdB+, TcdA-/TcdB+, and TcdA-/TcdB-, respectively. Conclusion: The results evidently support the hypothesis of a probable role of toxigenic strains of C. difficile in developing gastrointestinal complaints in patients with diarrhea. © TUBİTAK

Isolation of probiotic bacteria from raw camel's milk and their antagonistic effects on two bacteria causing food poisoning

Lactic acid bacteria (LAB) is one of the main classes of acid-producing organisms in the food industry, and they play a vital part in many food and feed fermentations. We isolated and performed molecular identification of LAB from raw camel's milk and assessed their protective effects against pathogenicity induced by Staphylococcus aureus and Escherichia coli. Fourteen samples of camel's milk were obtained from several districts under aseptic conditions. Bacteria isolation was performed by plating the samples on selective media. Isolates were identified by amplification of the 16S ribosomal RNA by PCR and sequencing. A total of 32 isolates were randomly picked, eight of which were analysed in this study. On the basis of phenotypic and genotypic methods, isolated LAB was included Leuconostoc mesenteroides, Lactobacillus plantarum, Weissella paramesenteroides and Weissella confuse. Antagonistic activity of isolated LAB against two pathogenic bacteria showed that they had more inhibitory activity against S. aureus subsp. aureus PTCC 1431 than E. coli ATCC 25922. This study discovered that raw camel's milk obtained from three districts of Kerman province contain LAB bacteria that have antagonistic properties on S. aureus. Keywords: Camel, lactic acid bacteria, milk, probioti

Monoclonal antibody directed to the PilQ -PilA DSL region in Pseudomonas aeruginosa improves survival of infected mice with antibiotic combination

The infections caused by Pseudomonas aeruginosa are related to high mortality and morbidity in critically ill patients because of multidrug resistance. Thus, we performed the efficacy of the monoclonal antibody (mAb) against PilQ -PilA DSL region (QA) in combination with antibiotics in a model of P. aeruginosa infection. In the present study, three clinically applicable antibiotics (levofloxacin, ceftazidime and gentamicin) and the anti-QA mAb were utilized for treatment of P. aeruginosa sepsis in mice. Reliably, in comparison with other treatment groups (antibody or antibiotic administration), the combination of antibiotic and anti-QA mAb essentially enhanced the survival of mice infected with P. aeruginosa PAO1. This synergistic effect was due to improved bactericidal effect, which prevented bacterial dissemination to different organs. Consequently, the antibiotic and anti-QA mAb combination gives a new effective strategy for the treatment of P. aeruginosa sepsis, particularly when large numbers of exceptionally virulent strains are present. © 2021 Elsevier Lt

Molecular characterization of the virulence genes gelE and cylA in the Enterococcus species isolated from clinical samples

Background: In recent years, Enterococcus spp. are considered as the most important nosocomial pathogens. Different factors are involved in the pathogenesis of these bacteria among which hemolysin (hyl) or cytolysin (cylA) and gelatinase (gelE) are the most important ones. The current study aimed to evaluating the prevalence of virulence genes cylA and gelE in the Enterococcus species isolated from patients by the polymerase chain reaction (PCR) technique. Methods: The study evaluated a total of 300 clinical samples isolated from patients hospitalized in Milad and Baqiatallah hospitals, Tehran, Iran. The isolated species were identified by culturing and routine biochemical methods. The antibiotic susceptibility testing was performed using the standard disk diffusion method, according to the guidelines of Clinical and Laboratory Standards Institute. The prevalence of cylA and gelE genes was assessed by PCR using specific primers. Results: Out of 300 clinical samples, 143 were identified as enterococci in which 128 (89.51) species were E. faecalis and 15 (10.48) E. faecium. Results of the antibiotic susceptibility testing showed the highest resistance against tetracycline and quinupristin, and the lowest resistance to linezolid, teicoplanin, and nitrofurantoin in the isolated enterococci. Of 143 isolated species, 114 (79.72) harbored gelE and 80 (55.94) carried cylA. Conclusion: Results of the current study showed that most species isolated from patients carried the important virulence factors of gelE and cylA, although other virulence factors can affect the incidence of infection. © 2020 Elsevier B.V

Bakterielle Ätiologie und Antibiotikaempfindlichkeit von Erregern von Infektionen des diabetischen Fußes

Aim: The aim of this study was to investigate anaerobic and aerobic bacteria profile and determination of antibiotic susceptibility pattern in aerobic bacteria.Method: Specimens were cultured using optimal aerobic and anaerobic microbiological techniques. Identification of bacterial isolates was performed by standard microbiological methods and antibiotic susceptibility testing was performed according to the guidelines of Clinical and Laboratory Standards Institute (CLSI).Result: 92 bacterial strains were isolated from 60 samples of diabetic foot ulcers. Predominant aerobic bacteria isolated from these infections were S. aureus (28%) followed by Enterobacteriaceae family (24%) including Escherichia coli (15%), Citrobacter spp. (4%), Enterobacter spp. (4%), and coagulase-negative Staphylococcus spp. (17%), Enterococcus spp. (15%), Pseudomonas aeruginosa (7%) and Acinetobacter spp. (4%). No Clostridium spp. were isolated and 4% Bacteroides fragilis obtained from anaerobic culture. All Gram-positive isolates were susceptible to linezolid while all Enterobacteriaceae showed sensitivity to imipenem.Conclusion: Most of DFIs specimens were poly microbial infection and predominant bacteria were S. aureus and B. fragilis . These wounds may require use of combined antimicrobial therapy for initial management.Zielsetzung: Es sollte die bakterielle Ätiologie (anaerobe und aerobe Flora) und Antibiotikaempfindlichkeit von Erregern beim diabetischen Fußsyndrom analysiert werden.Methode: Die Kultivierung erfolgte unter optimalen aeroben und anaeroben Bedingungen. Die Identifizierung der bakteriellen Isolate wurde mit mikrobiologischen Standardmethoden vorgenommen. Die Testung der Antibiotikaempfindlichkeit erfolgte gemäß den Richtlinien des Clinical und Laboratory Standards Instituts (CLSI).Ergebnisse: Von 60 Proben diabetischer Fußulcera wurden 92 Bakterienstämme isoliert. Dominierende Aerobier waren S. aureus (28%), gefolgt von Vertretern der Enterobacteriaceae (24%) einschließlich Escherichia coli (15%), Citrobacter spp. (4%), Enterobacter spp. (43%) und Coagulase-negativen Staphylococcus spp. (17%), Enterococcus spp. (15%), Pseudomonas aeroginosa (7%) und Acinetobacter spp. (4%). In den anaeroben Kulturen war in 4% der Ulcera Bacteroides fragilis nachweisbar, jedoch in keinem Fall Clostridium spp. Alle Gram-positiven Isolate waren gegen Linezolid empfindlich; alle Vertreter der Enterobacteriaceae waren gegenüber Imipenem empfindlich.Schlussfolgerung: Die meisten Infektionen bei den diabetischen Fußulcera waren durch eine Mischflora mit Dominanz von S. aureus und B. fragilis gekennzeichnet. Die Ulcera können daher in der Initialtherapie sinnvollerweise eine kombinierte antimikrobielle Therapie erfordern

Therapeutic bacteria to combat cancer; current advances, challenges, and opportunities

Successful treatment of cancer remains a challenge, due to the unique pathophysiology of solid tumors, and the predictable emergence of resistance. Traditional methods for cancer therapy including radiotherapy, chemotherapy, and immunotherapy all have their own limitations. A novel approach is bacteriotherapy, either used alone, or in combination with conventional methods, has shown a positive effect on regression of tumors and inhibition of metastasis. Bacteria-assisted tumor-targeted therapy used as therapeutic/gene/drug delivery vehicles has great promise in the treatment of tumors. The use of bacteria only, or in combination with conventional methods was found to be effective in some experimental models of cancer (tumor regression and increased survival rate). In this article, we reviewed the major advantages, challenges, and prospective directions for combinations of bacteria with conventional methods for tumor therapy. © 2019 The Authors. Cancer Medicine published by John Wiley & Sons Ltd