International Journal of Enteric Pathogens
Year:2016 | Volume:4 | Issue:2|Papers Count:11

Background: Bacterial resistance to beta-lactam is a major problem in all developed and developing countries. The genera of Klebsiella andEnterobacter are associated with opportunistic and nosocomial infections. All beta-lactamase genes can cause dissemination of resistance to beta-lactams.Objectives: The present studyaimedto investigate the phenotypic detection of beta-lactamases in Enterobacter and Klebsiella species isolated from clinical specimens.Materials and Methods: This cross-sectional study was performed on 59 Klebsiella spp. and 49 Enterobacter spp. isolated from clinical samples. They were confirmed using API 20E. These bacteria were evaluated for the production of extended-spectrum beta lactamase (ESBL), metallo-beta-lactamase (MBL) (IMP-1), and the pAmpC and iAmpC enzymes. This was done using the Clinical and Laboratory Standards Institute (CLSI) method, 2-mercaptopropionic acid, the cefoxitin method, and the use of imipenem as an enzyme inducer, respectively. Mask-ESBL production was also identified, using different concentrations of 3-amino-phenyl boronic acid compound. Data were analyzed with SPSS version 22.Results: In total, 38 (64.4%) Klebsiella spp. and 41 (83.7%) Enterobacter spp. produced at least one type of beta-lactamase. AmpCproducing Enterobacterspp. (71.4%), and ESBL-producing Klebsiella spp. (42.4%) had the highest prevalence of beta-lactamase types in each genus. There weretwobacteria in both types that were resistant to all antibiotics without producing any type of beta-lactamase.Conclusions: According to our findings, it is necessary to pay special attention to ESBL production in Klebsiella spp., while in Enterobacter spp., it is essential to search for AmpC production (chromosomal and plasmid). In addition, the genotypic evaluation of beta-lactamase variety in these bacteria may be necessary in different geographical areas.

Background: Chitosan, a liner polysaccharide, is a biocompatible and safe material for the delivery of therapeutic proteins and antigens, particularly via mucosal systems.Objectives: In this study, the production of antibodies in response to outermembraneproteinW (ompW) -loaded chitosan in BALB/c mice was evaluated.Materials and Methods: Mice were subjected to intraperitoneal injection of ompW or nasal administration of ompW-loaded chitosan on days 1, 14, and 28, and the antibodies were measured on day 42 with ELISA.Results: The titration of antibodies indicated that the nasal administration of ompW-loaded chitosan was better able to stimulate the immune response compared to intraperitoneal injections. However, the titration of total and IgG isotypes showed a significant difference between intraperitoneal and nasal immunization (P<0.01). A significant difference was also seen in serum IgA isotypes at over 1/80 titrations, but not at lower dilutions (P<0.01). Despite the serum antibodies, the results of lavage fluid analysis revealed that the IgG and IgA isotypes in the mice subjected to nasal immunization with ompW-loaded chitosan were significantly higher than in the other group (P<0.01).Conclusions: Based on the preliminary results presented in this research, it is suggested that ompW-loaded chitosan could be a suitable choice for nasal application to immunize the host againstVibrio cholerae. However, more work is required to determine the efficiency of the antibodies in neutralizing the bacterial toxin or bacterial movement.

Background: Campylobacter species are responsible for the majority of cases of food-borne gastroenteritis. The sources of the disease outbreaks are often contaminated water or milk, and consumption of undercooked poultry product is the main cause of sporadic campylobacteriosis cases.Objectives: The aims of this study were to determine the prevalence of Campylobacter gastroenteritis in childrenandto differentiate the interfering species using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods at the Bahonar hospital in Karaj, Iran.Patients and Methods: A total of 150 stool samples were collected from children under 10 years old during the summer of 2014.PCR was performed using genus- and species-specific primers and RFLP was done usingAluI and TasI enzymes.Results: The results showed the amplification of 400 and 491 bp segments and Campylobacter contamination in 30 (20%) samples; 5 out of 30Campylobacter positive samples (16.66%) were identified as C. jejuni, 20 (66.66%) as C. coli, 3 (10%) as C. jejuni and C. coli (mixed infection), and 2 (6.66%) were identified as non-jejuni, non- coli Campylobacter using the PCR method. Following the evaluation of RFLP results, 7 positive samples (23.33%) showed the electrophoretic pattern ofC. jejuni, 21 (70%) showed the electrophoretic pattern ofC. coli, and 2 (6.6%) showed both of the patterns and mixed contamination with jejuni and coli species. The results of digestion withTasI did not show any C. lari or C. upsaliensis patterns.Conclusions: The results of this study showed high percentage of Campylobacter contamination in the tested stool samples. The other surprising finding was the high rate ofCampylobacter coli positive samples; the difference between the results of PCR using species-specific primers (hipo and asp) and the RFLP method (electrophoretic patterns) in some of the positive samples confirms the hypothesis of variations in nucleotide sequences of thehipo primer binding site in some Iranian isolates of Campylobacters.

Background: Among diarrheagenic strains of Escherichia coli, entrotoxigenic Escherichia coli (ETEC) is most commonly associated with diarrhea in calves and lambs. Broad use of antimicrobials in agriculture selects for resistant bacteria that may enter the food chain, and potentially result in foodborne disease in humans that is less responsive to treatment with conventional antibiotics.Objectives: This study was carried out to identify antimicrobial resistance in ETEC and non-ETEC isolated from diarrheic calves.Materials and Methods: Disk diffusion methods and PCR were used to detect antimicrobial resistance. Antimicrobial susceptibility testing was performed by using the standards recommended by the clinical and laboratory standard institute (CLSI). Multiplex or monoplex PCR amplification was used to identify eight antibiotic-resistant genes, includingbla SHV, tet (A), Sul1, aac (3) -IV, ere (A), catA1, cmlA, aadA1 and qnr (A), which confer resistance to penicillin, tetracycline, sulfonamide, gentamicin, erythromycin, chloramphenicol, streptomycin, and fluoroquinolone, respectively.Results: Antimicrobial resistance rates for ETEC isolates were detected against penicillin (100%), tetracycline (90.9%), erythromycin (90.9%), streptomycin (90.9%), sulfonamide (63.6%), chloramphenicol (63.6%), gentamicin (45.4%) and fluoroquinolone (36.3%). Furthermore, according to the results, antimicrobial resistance for non-ETEC isolates was detected against penicillin (100%), followed by erythromycin (97.6%), tetracycline (93%), streptomycin (91.8%), sulfonamide (73.2%), chloramphenicol (51.1%), fluoroquinolone (44.1%), and gentamicin (34.8%). In addition, the distribution of the resistant genes for ETEC isolates wereere (A) (100%), catA1 (100%), cmlA (100%), aadA1 (100%), Sul1 (72.7%), tet (A) (54.5%), aac (3) -IV (54.5%), bla SHV (36.3%), and qnr (A) (9%). For non-ETEC isolates they were ere (A)(100%), aadA1 (100%), Sul1 (87.2%), catA1 (67.4%), cmlA (67.4%), tet (A) (48.8%), aac (3) -IV (48.8%), bla SHV (41.8%), and qnr (A) (3.4%).Conclusions: Among the eight antimicrobial agents examined in this investigation, the least resistance was observed against gentamicin and fluoroquinolone in both ETEC and non-ETEC isolates. Therefore, carrying out antimicrobial susceptibility tests before drug prescription seems necessary.

Introduction: Diarrhea is the most common cause of death in neonatal calves. The most important agents of diarrhea in young calves include bacteria, viruses, and protozoa. Only limited attention has been paid to the role of fungi in calves’ diarrhea.Case Presentation: We report on a neonatal calf with fungal diarrhea caused by Candida albicans. The calf has had dysentery in the previous 10 days despite good appetite. The calf was then treated with oxytetracycline tabulations for 5 days.Conclusions: Yeasts and molds are sometimes associated with lesions in the stomach or intestines of scouring calves, but there is very limited information about their role in calf diarrhea. In this study, C. albicans was isolated in a 15-day-old dysenteric calf.These organisms are not a primary cause of diarrhea in calves, but like in children, they are possibly opportunistic pathogens that proliferate and invade the intestinal mucosa following antibiotic therapy.

Background: Toxoplasma gondii is an obligate intracellular parasitic protozoan, capable of infecting a wide range of warm-blooded hosts, including humans. Infection withT. gondii can be life threatening in immunocompromised people. Moreover, infection with T. gondiiduring pregnancy can lead to severe problems for fetus.Objectives: This study was performed to evaluate the seroepidemiological status of toxoplasmosis in pregnant women in Urmia, Iran.Materials and Methods: In this cross-sectional study, a total of 156 serum samples were selected randomly from pregnant females and their anti-Toxoplasma IgG and IgM antibodies were screened using routine commercial ELISA kits. The probable risk factors related to toxoplasmosis were asked and collected in pregnant women of Urmia.Results: Of the 156 sera, 44 were positive for T. gondii IgG antibodies and 112 were negative. The mean age of women was 19.68 and the rate of IgM-positive cases forT. gondii infection was 2.6%.Conclusions: According to our study, Toxoplasma regular screening program in pregnant women is strongly recommended, since a considerable number of pregnantwomenin our area are susceptible to infection with acuteT. gondii over the course of pregnancy.

Background: Uropathogenic E. coli (UPEC) is the primary cause of humanurinary tract infections (UTIs) worldwide. Moreover, there has been renewed and growing interest in using older antibiotics for treatment, such as aminoglycosides.Objectives: The goal of this study was to determine the plasmid profile patterns of UPEC isolates harboring the aminoglycoside resistance geneaac (3) -IIa.PatientsandMethods: Atotal of 276 uropathogenic E. coli (UPEC) samples were isolated from UTI patients at the Tehran heart center in Tehran, Iran. Antimicrobial susceptibility testing against five aminoglycosides was performed by the disk diffusion method, and theaac (3) -IIa gene was detected via PCR. Moreover, plasmid profiling was carried out on those UPEC isolates harboring the aac (3) -IIa gene. Finally, the similarities among these isolates were determined on the basis of their plasmid profiles.Results: The highest level of resistance was seen for tobramycin (24.6%), and the aac (3) -IIa gene was found in 51 isolates. Twentyseven different plasmid profiles were identified among the isolates harboring theaac (3) -IIa gene, with the 15 kb plasmid being the most common. Moreover, no significant correlation was found between the resistance patterns and the number of plasmids. The cluster analysis based on the plasmid profiles grouped the isolates into five different clusters, of which cluster one was the largest (containing 14 of 51 isolates).Conclusions: Ourdata suggest the monitoring of aminoglycoside resistance, andits consideration in the empirical therapy of UPEC infections.

Background: Finding alternatives to antibiotics for poultry production is very important because there are increasing concerns about antibiotic resistance. So, researchers have been directed to the research back to natural antimicrobial products. Some researchers stated that probiotics can stimulate the immune system and play an important role in shaping the immune system.Objectives: Theaimof this studywasto examine the effect of a commercial probiotic mixture (AquablendAvianÒ) supplementation to the drinking water of broiler chickens on the immune response against Newcastle and influenza diseases vaccines.Materials and Methods: In this study, 180 one-day-old broiler chickens were purchased and divided randomly into 3 groups (n= 60 for each group). Chickens in groups A and B received 300 mg of the probiotic in drinking water for first 3 days and first 7 days, respectively. Chickens in group C were kept as a control group and did not receive probiotic. All groups were vaccinated with live Newcastle vaccine (B1 strain) intraocularly on 8th day, and AI-ND killed vaccine (subtype H9N2) subcutaneously at the back of the neck on 8th day. Two mL of blood samples were collected before vaccination as well as on days 14, 28 and 35 postimmunization.Ten chickens of each group were bled randomly and an antibody titer against Newcastle disease vaccine and AI-ND killed vaccine (subtype H9N2) was determined by the hemagglutination-inhibition test.Results: The results of the present study showed that oral administration of the probiotic for 7 days significantly increased the specific antibody response to Newcastle vaccine compared to the control group (0.75 - 1.6 log, based on log2), while the probiotic administration had no significant effect on antibody productions against avian influenza vaccine as compared to the control group.Conclusions: Oral administration of Aquablend Avian® probiotic strains including Lactobacillus, Streptococcus and Bifidobacterium for 7 days can enhance the systemic antibody response to Newcastle vaccine in broiler chickens.

Background: Nowadays, microbial food safety is an increasing public health concern worldwide, especially in developing countries.Objectives: The aim of this study was to apply established in vitro tests to evaluate the antimicrobial activity of the Lactobacilli.isolated from two traditional Iranian fermented dairy-cereal based foods.Materials and Methods: A total of 23 samples of Kashk-e Zard and 27 samples of Tarkhineh were collected from different regions of Iran. Lactobacillus spp. was isolated and identified by standard methods. The antibacterial effects ofLactobacillus isolates were implemented by well diffusion method. Kinetic study was conducted with a bacteriostatic activity in vitro in the presence ofLactobacillus supernatants.Results: The results showed an antimicrobial activity of the Lactobacillus strains isolated from Kashk-e Zard and Tarkhineh against Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Salmonella typhimurium according to agar well diffusion test. In addition, kinetic study revealed a significant bacteriostatic activity ofLactobacillus supernatants.Conclusions: Kashk-e Zard and Tarkhineh seemed to have probiotic properties, deserving further studies.

Background: Oneof themostcommondiseases worldwide is urinary tract infection (UTI). Themainagents causing these infections are bacteria. Urinary tract infections occurwhenuropathogens colonize the urethra, migrate to the bladderandinvade urinary tract cells.Objectives: The purpose of this study was the detection of uropathogens causing UTIs, as well as serotyping and antibiotic susceptibility of the most common bacteria.Materials and Methods: The study was performed on 300 urine samples collected from patients referred to Koohdasht Imam Khomeini hospital of Lorestan province. After culturing the samples and determination of uropathogens, antibiotic susceptibility test was performed by the Kirby-Bauer disk diffusion method. Serotyping was performed for the most common uropathogens by polyvalent and monovalent antisera.Results: Of the 300 samples, 61 samples (20.33%) were positive for UTIs. Among these, 49 samples (80.33%) were Gram-negative bacteria and 12 (19.67%) Gram-positive. The most common uropathogens in UTIs wereEscherichia coli (55.74%), Proteus species (11.47%), Staphylococcus epidermidis(11.47%), Citrobacter species (8.20%), Staphylococcus aureus (8.20%) and Klebsiella species (4.92%), respectively.The rate of UTI in females (83.61%) was more than males (16.39%). The highest level of resistance was towards trimethoprim/ sulfamethoxazole and the lowest to ampicillin, ciprofloxacin and nitrofurantoin. The most common uropathogen wasEscherichia coliand the most common serotypes were O142: K86 and O25: K11, respectively.Conclusions: The treatment of UTIs and resistance control in bacteria should be done based on common strains and choosing an effective antibiotic. Therefore, the determination of prevalent bacterial strains in UTIs of each region based on laboratory tests is very important.

Background: Prevention of foodborne pathogens is essential to control infectious diseases; Salmonella spp. is referred to as the most common causative agent of foodborne illnesses.Objectives: The current study aimed to determine the prevalence of Salmonella enterica subsp. enterica in broiler flocks in Mazandaran province, north of Iran and find the potential risk factors including: age, size of flock, strain, season, vaccination program and use of antibiotics.Materials and Methods: From March 2012 to December 2013, a total of 50 flocks were selected in slaughterhouse and 20 cloacal samples were collected from each flock. Every five samples were pooled and investigated forSalmonella spp. using polymerase chain reaction (PCR).Results: Thirteen flocks out of 50 (26%) were positive for Salmonella species. Chances of Salmonella spp. detection was higher in flocks with lower age (P=0.41). Increasing flock population was associated with increased chance ofSalmonella spp. isolation (P =0.21). The risk of salmonellosis in broiler flocks was increased when no antibiotics were given to day-old chicks. There was no significant difference (P=0.30) in the prevalence of salmonellosis among different broiler strains.Conclusions: In the current study, six risk factors were assessed for Salmonella spp. contamination in broiler flocks. Some of these factors contributed to the risk of salmonellosis in broiler flocks.