marA efflux pump gene expression in Salmonella enteritidis strains treated with Artemisia tournefortiana hydroalcoholic extract and comparison with commercial efflux pump inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP)

Background: Salmonella enterica subsp. enterica serovar Enteritidis is a food-borne pathogenic bacterium that has recently become resistant to most quinolone antibiotics. The MarA efflux pump plays a significant role in the development of ciprofloxacin resistance in S. Enteritidis strains. The aim of this study was comparative evaluation of anti-efflux activity of Artemisia tournefortiana extract and commercial efflux inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) on marA efflux pump gene expression in S. Enteritidis clinical strains. Materials and Methods: In this experimental study, Artemisia tournefortiana extract was prepared using maceration method. Subsequently, MarA efflux pump was detected in 20 clinical strains of S. Enteritidis via cartwheel and PCR methods. Finally, after treatment of strains with subMIC concentration of extract and 20 µg/L and CCCP, their anti-efflux activity against MarA efflux pump was studied using Real Time PCR. Results: The results of cartwheel and PCR methods indicated that all of ciprofloxacin resistant strains had MarA efflux pump. Subsequently, after treatment of strains with subMIC concentration of extract and CCCP, results show that both component have the ability to inhibit the MarA efflux pump, significantly. Conclusion: Considering the results of MarA efflux inhibition by A. tournefortiana and CCCP, it seems that this plant can be used as a potential source of drug use as a suppository pump inhibitor instead of CCCP.

Evaluation of antimicrobial activity of Lactobacillus plantarum and ruteri on Acinetobacter baumannii isolated from nosocomial infections

زمینه و هدف : اسینتو باکتر از پاتوژن های فرصت طلب بوده و از عوامل مهم عفونت های بیمارستانی محسوب می شوند و می توانند طیف وسیعی از عفونت ها نظیر سپتی سمی و پنومونی را ایجاد نمایند و نسبت به بیشتر کلاس های آنتی بیوتیکی مقاوم هستند . امروزه استفاده از مواد مترشحه از باکتری های پروبیوتیک به عنوان مهار کننده و ضد باکتری مد نظر است.این مطالعه به منظور تعیین فعالیت ضد میکروبی لاکتوباسیلوس روتری و پلانتاروم نسبت به اسینتو باکتر بومانی شایع در عفونت های بیمارستانی بوده است. روش ها : در این بررسی پس از جدا سازی اسینتو باکتر از بیماران بستری در بیمارستان، مقاومت آنتی بیوتیکی آن بهمراه دو سویه استاندارد لاکتوباسیلوس پلانتاروم و روتری بررسی شد . سپس از محلول رویی کشت 48 ساعته دو سویه لاکتوباسیل برای بررسی فعالیت مهارکنندگی آنها بر علیه اسینتو باکتر بومانی در دو حالت فعال و غیر فعال به روش چاهک در آگار بررسی شد. یافته ها : لاکتوباسیلوس پلانتاروم و روتری به آنتی بیوتیک های ونکومایسین ، ایمی پنم ، سیپروفلاکساسین و سفتازیدیم مقاوم و به پیپراسیلین ، کلیستین و کوتریموکسازول حساسیت نشان دادند. محلول رویی کشت لاکتوباسیلوس پلانتاروم و روتری فعال در آب اکسیژنه و بدون تغییر pH ،خاصیت ضد باکتریایی بیش تری نسبت به محلول غیر فعال آن داشته است. نتیجه گیری : محلول رویی کشت دو سویه لاکتوباسیلوس فعالیت چشمگیری بر علیه اسینتوباکتر بومانی تحت شرایط اسید و تولید آب اکسیژنه دارد، در حالی که محلول غیر فعال شده آن فعالیت ضد باکتریایی ندارد

Molecular identification of Pseudomonas aeruginosa recovered from cystic fibrosis patients

Objective. Precise identification of various morphotypes of Pseduomonas aeruginosa which developed during cystic fibrosis (CF) is of prime importance. We aimed to identify the isolates of P. aeruginosa recovered from CF patients at the genus and species level through primers targeting oprI and oprL genes via PCR. Methods. Sputum samples or throat swabs were taken from 100 CF patients and plated on cetrimide agar. All suspected colonies were primarily screened for P. aeruginosa by a combination of phenotypic tests. Molecular identification of colonies was per- formed using specific primers for oprI and oprL genes.Results. Based on phenotypic tests, P. aeruginosa isolates were recovered from 40% of CF patients. Forty isolates yielded ampli- con of oprI gene using genus-specific primers confirming the identity of fluorescent pseudomonads. However, 37 of 40 isolates yielded amplicon of oprL gene using species-specific primers, verifying the identity of P. aeruginosa. Conclusion. This study showed that the species-specific PCR tar- geting oprL gene can be used as accurate test for identification of highly adaptable P. aeruginosa in CF patients. This procedure may provide a simple and reliable method for identification of various morphotypes

Evaluation the cytotoxic effect of cytotoxin-producing Klebsiella oxytoca isolates on the HEp-2 cell line by MTT assay

Background: The cytotoxic effects on epithelial cells of the human are not observed in other strains of Klebsiella spp and are only observed in K. oxytoca strains. MTT assay was used to evaluate cytotoxic activity. In this study, colorimetric method was used to evaluate the cytotoxic effect of cytotoxin-producing isolates on Hep-2 cell line and determines the percentage of surviving cells. Materials and methods: In this study, we collected a total of 75 K. oxytoca strains isolate and we detected the production of toxins and their cytotoxic effects on HEp-2 cells. Colorimetric method such as MTT assay was used to evaluate the cytotoxic effect of cytotoxin-producing isolates on Hep-2 cell line and determines the percentage of surviving cells. Results: Nine isolates had cytotoxic effects on HEp-2 cells. The results of MTT assay showed that the isolated strains were different from the control stain in terms of toxinogenicity and cytotoxic effects on HEp-2 cells at the studied dilutions (1:3, 1:6, 1:12, 1:24, 1:48, and 1:96). Conclusions: In the current study, Percentage of Hep-2 surviving cells exposed to 1:3, 1:6, 1:12, 1:24, 1:48, and 1:96 supernatant dilutions of cytotoxin-producing Klebsiella oxytoca isolates was different

Identification of Klebsiella pneumoniae Carbapenemase-producing Klebsiella oxytoca in Clinical Isolates in Tehran Hospitals, Iran by Chromogenic Medium and Molecular Methods

Objectives: Production of carbapenemase, especially Klebsiella pneumoniae carbapenemases (KPC), is one of the antibiotic resistance mechanisms of Enterobacteriaceae such as Klebsiella oxytoca. This study aimed to investigate and identify KPC-producing K. oxytoca isolates using molecular and phenotypic methods. Methods: A total of 75 isolates of K. oxytoca were isolated from various clinical samples, and were verified as K. oxytoca after performing standard microbiological tests and using a polymerase chain reaction (PCR) method. An antibiotic susceptibility test was performed using a disc diffusion method according to the Clinical and Laboratory Standards Institute guidelines. CHROMagar KPC chromogenic culture media was used to examine and confirm the production of the carbapenemase enzyme in K. oxytoca isolates; in addition, PCR was used to evaluate the presence of blaKPC gene in K. oxytoca strains. Results: Of a total of 75 K. oxytoca isolates, one multidrug resistant strain was isolated from the urine of a hospitalized woman. This strain was examined to assess its ability to produce carbapenemase enzyme; it produced a colony with a blue metallic color on the CHROMagar KPC chromogenic culture media. In addition, the blaKPC gene was confirmed by PCR. After sequencing, it was confirmed and deposited in GenBank. Conclusion: To date, many cases of KPC-producing Enterobacteriaceae, in particular K. pneumoniae, have been reported in different countries; there are also some reports on the identification of KPC-producing K. oxytoca. Therefore

Investigation of the Frequency of Foodborne Botulism in Patients Referred to Loghman Hospital in Tehran City, Iran, From 2008 to 2019

Background: Foodborne botulism is a fatal paralytic illness caused mainly by the neurotoxin produced by an anaerobic bacterium called Clostridium botulinum. In this study, the frequency of foodborne botulism in patients referred to a hospital in Iran has been reviewed for ten years.Methods: In this routine database study, medical records of patients with foodborne botulism referred to Loghman Hospital in Tehran City, Iran, from March 20, 2008, to March 20, 2019, were reviewed. Information on variables of age, sex, place of residence, food consumed, clinical symptoms of patients (such as dysphagia, nausea, vomiting, ataxia, etc.), toxin type, and length of hospitalization were collected with a researcher-made questionnaire. Finally, the collected data were analyzed in SPSS-24 with descriptive and analytical statistical tests.Results: In this study, 61 suspected botulism patients were clinically diagnosed in Loghman Hospital, of whom 55 patients were clinically suspected of foodborne botulism, 5 patients had iatrogenic botulism, and 1 patient had infant botulism. Of these 55 patients with the clinical diagnosis of foodborne botulism, 19 patients were confirmed by laboratory examinations, and 2 patients died. Sixteen patients confirmed by laboratory had neurotoxin botulinum type A. The mean age of the patients was 36.9 years with a standard deviation of 18.6 years. About 54.5% of the patients were male and 45.5% female. Weaknesses (58.2%), ptosis (droopy eyelid) (56.4%), and diplopia (double vision) (52.7%) were the common clinical symptoms of the patients under study. Canned foods and dairy products were the main foods consumed by the patients. The duration of admission time ranged between 1 and 41 days, with an average of 7.7 days. About 23.64% of patients were admitted to the intensive care unit.Conclusion: The prevalence of foodborne botulism is rare compared with other food poisonings but is still a major public health problem due to the consumption of traditional food products and unboiled canned foods in Iran

Study of VanA, B, C, D, E Genes in Vancomycin Resistant Enterococci Isolated from Retailed Dried Vegetables in Tehran, Iran

Background: Enterococcus spp. are resistant to many antimicrobials including vancomycin. They may be found in foods and water.Objective: In the current study, van genes were investigated in vancomycin resistant enterococci (VRE) isolated from dried vegetables in Tehran, Iran.Materials and Methods: In this study, 140 dried vegetable samples were collected from local retailers in Tehran, Iran, 2015. Bacteria were isolated using culture, biochemistry and molecular methods. Susceptibility of the enterococcal isolates was assessed to six antibiotics of ampicillin, chloramphenicol, erythromycin, gentamicin, tetracycline and vancomycin using Kirby-Bauer method. The prevalence of vanA, B, C, D, E genes was molecularly studied in VRE using polymerase chain reaction (PCR) and sequencing techniques.Results: Of 140 dried vegetable samples, Enterococcus spp. strains were isolated from 84 samples (60%). Totally, 48% of the isolates were resistant to vancomycin. Of 41 vancomycin-resistant enterococcal isolates, vanA was found in 23 (56.1%), vanB in 8 (19.5%) and vanC in 2 (4.9%) isolates. No vanD or vanE was found in the isolates. Results have shown a high rate of contamination with Enterococcus spp., especially VRE, in dried vegetables in Tehran.Conclusion: Therefore, further hygienic regulations such as personal training and food processing, transportation, storage and marketing must be routine in food industries and local retailers

Investigation the Shigella serotypes invasive cells isolated from patients with diarrhea in HEp-2 cell culture

Background and aims: Diarrhea is one of the most prevalent cause of children`s death in developing countries. Gastrointestinal diseases are the cause of much death among the children under the age of 5 every year. In this study the invasiveness character of Shigella strains was investigated by HEp-2cell cell culture technique. Methods: In this descriptive study, 280 rectal swabs (140 with dysentery and 140 watery diarrhea) from patients suffering from diarrhea before using any antibiotic and 140 from healthy people as control group were collected. These specimens were cultured in Hektoen and XLD agar as selective and differential media, then after 24 hours incubation in 37˚C their morphology were studied and finally the isolates were confirmed with biochemical tests. Shigella spp strains consist of 20 collection strains were used for consideration of invasiveness in Shigella. Antibiotic typing also performed according to CLSI instructions. Results: Thirty six strains of Shigella (8.6%) were isolated from thesamples under the study. Most strains isolated from patients, were Shigella flexneri isolated with 16. Our study on HEp-2 cell cultures showed that only 14 (9 isolates, 5 collections) had invasive properties of Shigella strains. Conclusion: The results show that firstly all Shigella isolates are not capable of invading intestinal epithelial cells Secondly invasion is not a constant attitude and it would not go away by tim

Identification of cytotoxin-producing Klebsiella oxytoca strains isolated from clinical samples with cell culture assays

BACKGROUND: Klebsiella oxytoca is an opportunistic pathogen which damages intestinal epithelium through producing cytotoxin tilivalline. This toxin plays a role in the pathogenesis of bacteria and is the main virulence factor which leads to antibiotic-associated hemorrhagic colitis progress. MATERIALS AND METHODS: In this study, we collected a total of 75 K. oxytoca strains isolated from the stool, urine, blood, wounds, and sputum and evaluated them in terms of the production of toxins; we detected their cytotoxic effects on HEp-2 cells. RESULTS: Of all the isolates, five K. oxytoca strains isolated from the stool cultures, two strains isolated from the blood cultures, one strains isolated from the wound cultures, and one strains isolated from the urine cultures had cytotoxic effects on HEp-2 cells. The strains isolated from sputum cultures had no cytotoxic effects on HEp-2 cells. CONCLUSIONS: In the current study, the majority of strains isolated from the stool of the patients included cytopathic effects on HEp-2 cells. Copyright © 2017 Elsevier Ltd. All rights reserved