Hektoen Enteric Agar Research Articles

Prevalence of plasmid-mediated quinolone resistance genes and biofilm formation in different species of quinolone-resistant clinical Shigella isolates: a cross-sectional study

BackgroundThe purpose of this study was to look into the presence of plasmid-mediated quinolone resistance (PMQR) genes and biofilm formation in several species of clinical Shigella isolates that were resistant to quinolones.MethodsThe stool samples of 150 patients (younger than 10 years) with diarrhea were collected in this cross-sectional study (November 2020 to December 2021). After cultivation of samples on Hektoen Enteric agar and xylose lysine deoxycholate agar, standard microbiology tests, VITEK 2 system, and polymerase chain reaction (PCR) were utilized to identify Shigella isolates. The broth microdilution method was used to determine antibiotic susceptibility. PMQR genes including qnrA, qnrB, qnrC, qnrD, qnrE, qnrS, qnrVC, qepA, oqxAB, aac(6′)-Ib-cr, and crpP and biofilm formation were investigated in quinolone-resistant isolates by PCR and microtiter plate method, respectively. An enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) technique was used to determine the clonal relatedness of quinolone-resistant isolates.ResultsA total of 95 Shigella isolates including S. sonnei (53, 55.8%), S. flexneri (39, 41.1%), and S. boydii (3, 3.2%) were identified. The highest resistance rates of the isolates were against ampicillin (92.6%, n = 88/95). Overall, 42 of 95 (44.2%) isolates were simultaneously resistant against two or more quinolones including 26 (61.9%) S. sonnei and 16 (38.1%) S. flexneri. All isolates were multidrug-resistant (resistance to more than 3 antibiotics). The occurrence of PMQR genes was as follows: qnrS (52.4%), qnrA and aac(6′)-Ib-cr (33.3%), and qnrB (19.0%). The prevalence in species was as follows: 61.5% and 37.5% (qnrS), 19.2% and 56.3% (qnrA), 38.5% and 25.0 (aac(6′)-Ib-cr), and 19.2% and 18.8% (qnrB) for S. sonnei and S. flexneri, respectively. The other PMQR genes were not detected. In total, 52.8% (28/53) of quinolone-susceptible and 64.3% (27/42) of quinolone-resistant isolates were biofilm producers. Biofilm formation was not significantly different between quinolone-resistant and quinolone-susceptible isolates (P-value = 0.299). Quinolone-resistant isolates showed a high genetic diversity according to the ERIC-PCR.ConclusionIt seems that qnrS, qnrA, and aac(6′)-Ib-cr play a significant role in the quinolone resistance among Shigella isolates in our region. Also the quinolone-resistant S. flexneri and S. sonnei isolates had a high genetic diversity. Hence, antibiotic therapy needs to be routinely revised based on the surveillance findings.

Evaluation of Salmonella Enteritidis Isolated from Layer Hens and Murine Fecal Pellets in Poultry Farms of Libya

The rodents play a significant role in the transmission of Salmonella between farms and regions. The present study aimed to compare the virulence of Salmonella enteritidis isolated from fecal samples of laying hens and murine within the same poultry house but different regions in Libya using Vivo-quantitative measurement of invasiveness (chicken intestinal loop model). A total of 540 cloacal swabs from laying hens (Hy-line brown chickens) aged 36 weeks and 200 batches of murine fecal pellets were collected from the same poultry house at Gaser Bin Gisher and Furnag regions in Libya. The samples were passed on pre-enrichment broth (Buffered Peptone Water) and enrichment broths (Rappaport Vassiliadis, Selenite broth, and tetrathionate), then the samples were cultured onto Xylose Lysine Deoxycholate agar, brilliant green agar, Salmonella Shigella agar, and Hektoen enteric agar. Single colonies were selected and stained by gram stain and tested biochemically using analytical profile index (API) 20 tests. Salmonella enteritidis was isolated from all the collected samples. The invasion of Salmonella enteritidis isolated from laying hens and murine feces was significantly higher in the anterior inoculation position compared to the posterior position of jejunum in both regions. The account of Salmonella enteritidis isolated from laying feces of hens and murine at Gaser Bengasher region was significantly higher than that isolated from the AlFurnge region. In the present study, the rodents act only as mechanical transmitters without affecting Salmonella invasiveness capacity. Furthermore, the invasion of Salmonella enteritidis depends on the inoculation position in the jejunum. Moreover, the invasiveness variation of Salmonella enteritidis isolated from the Gaser Bengasher and AlFurnge regions could be attributed to the presence of different Salmonella strains in the studied area. Salmonella enteritidis isolated from poultry and murine in the current study was sensitive to gentamicin, ciprofloxacin, and enrofloxacin and resistant to doxycycline, chloramphenicol, sulfafurazol, and ampicillin.

Antibiotic resistance of enteropathogenic bacteria in a teaching hospital in North Khuzestan during a three-year period.

Gastrointestinal infections affect many people annually. The most common bacterial agents involved in these infections are enteropathogenic bacteria and in the continuation of using broad-spectrum antibiotics, Clostridium difficile-associated diarrhea is involved, especially in hospitalized patients. The aim of the present study was to investigate the pattern of antibiotic resistance among enteropathogenic bacteria. In this cross-sectional study, 163 samples of patients with diarrhea in Dezful Ganjavian Hospital were examined. The samples were cultured in MacConkey, Hektoen enteric agar and GN broth, and cycloserine cefoxitin fructose agar media and incubated under standard conditions. In order to identify enteropathogenic bacteria, biochemical tests and serological confirmatory tests were used. Antibiotic resistance pattern of the isolates was investigated by Kirby-Bauer disk diffusion susceptibility test. The frequency of pathogenic bacteria includes 41.1% of Shigella flexneri, followed by 41.1% of S. sonnei, 6.7% of Enteropathogenic E. coli, 5.5% of Salmonella enterica Serogroup B, and 5.5% of Shigella dysenteriae. The results revealed a total of 46 patients with orders regarding C. difficile culture, no C. difficile was isolated from the samples. The studied isolates showed the highest resistance to trimethoprim-sulfamethoxazole, and ceftriaxone (88.3%), and the most effective antibiotic in the treatment of patients was ciprofloxacin with 86% sensitivity. Susceptibility to antibiotics was different among the isolates, which shows that the early identification of the infection agent and the selection of the correct antibiotic treatment are effective in improving the gastrointestinal infection and preventing the spread of the infection.

Deteksi keberadaan bakteri pengkontaminasi pangan Salmonella sp. pada telur

Eggs are a source of animal protein which can be contaminated by pathogenic microorganisms such as Salmonella sp. which is dangerous to human health. The aim of this research is to determine the presence of Salmonella sp bacteria. on chicken eggs. This research was carried out using chicken egg samples which were then tested at the Public Health Laboratory of the Balai Besar Veteriner Maros using 3 selective media for colony growth, namely Xylose Lysine Deoxychoalate agar (XLD), Hektoen Enteric agar (HE) and Bismuth Salt Agar (BSA) media. The results obtained showed that the 3 test media used showed negative results or no growth of Salmonella sp. bacteria, so it can be concluded that the egg samples tested in this study were not contaminated with the pathogenic bacteria Salmonella sp..

Antibiotic Profiles of Enteric Pathogens Isolated from Nigerian Currency Notes

Background: Currency notes are exchangeable fomites handled by many persons daily and can potentially carry enteric pathogens on their surfaces. Infections caused by these pathogens have a global impact on public health. This study aimed to analyse the Nigerian currency notes Naira for the presence of enteric bacteria, particularly drug-resistant strains. Methods: Sixty-four Nigerian currency notes were randomly collected from various sources. Using the spread plate technique, an aliquot of 0.1ml of 10-6 dilution of each sample suspension was inoculated onto Eosin Methylene Blue agar and Hektoen Enteric agar plates. Following incubation, colonies were counted and recorded in colony-forming units per milliliter, and morphologic features were observed. Bacterial isolates were then Gram-stained, tested for motility and characterized using standard biochemical techniques. Antimicrobial profiles of bacterial isolates were determined using the Kirby-Bauer modified disc diffusion method. Results: Preliminary analysis showed that 67.2% of currency notes were contaminated. The 100 Naira notes had the highest contamination rates with bacterial mean counts of 1.22×1010 cfu/ml. Three different species of enteric bacteria were isolated. The predominant pathogens were Escherichia coli (44.2%) and Salmonella spp. (44.2%). All isolates recovered were 100% susceptible to amikacin, gentamicin, and ciprofloxacin, while 97.7% were resistant to penicillin. Escherichia coli was resistant to ampicillin (100%) and trime-thoprim-sulfamethoxazole (89.5%). Conclusion: This study showed that the Nigerian currency notes harbour enteric pathogens capable of causing serious infections to handlers. Therefore, improved hygiene practices, especially after handling currency notes, should be encouraged to prevent the spread of these pathogens.

Prevalence of Salmonella Typhi, Staphylococcus aureus and intestinal parasites among male food handlers in Laghouat Province, Algeria

Background: Food-borne diseases are a global public health problem, most especially in developing countries. Food handlers with a low level of personal hygiene may be colonized or infected by a wide range of enteric pathogenic micro-organisms including intestinal parasites and bacteria. The aim of this study is to determine the prevalence of Salmonella Typhi, Staphylococcus aureus and intestinal parasites among male food handlers in Laghouat province, southern Algeria.
 Methodology: In this cross-sectional study, stool samples and fingernail samples of both hands were collected from 155 randomly selected male food handlers. Stool specimens were examined by direct wet mount, formalinether concentration, xenic invitro culture and staining methods for parasitological identification. For bacterial isolation, standard culture media including Hektoen agar, Salmonella-Shigella (SS), Mannitol salt, and Blood agar plates were used. Conventional biochemical tests were used for identification of S. Typhi and S. aureus. Antimicrobial susceptibility test (AST) was performed for bacterial isolates by the Kirby-Bauer disk diffusion method. Data analysis was done using Minitab version 19 software, and Pearson’s Chi-square test was used to determine association between categorical variables. P value < 0.05 was considered statistically significant. 
 Results: The overall prevalence rate of intestinal parasites among the study subjects was 40% (62/155). Blastocystis spp was the most frequent parasite isolated (16.8%), followed by Giardia intestinalis (8.4%), Entamoeba histolytica/dispar (7.7%), Entamoeba coli (3.2%), Trichomonas intestinalis (2.6%) and Endolimax nana (1.3%). Stool cultures revealed 4 (2.6%) positive samples for S. Typhi, and S. aureus was isolated from fingernail contents of 23 (14.8%) subjects. All S. Typhi isolates were sensitive to imipenem and ciprofloxacin while S. aureus isolates show high sensitivity to pristinamycin. Hand washing with soap, finger nail status and clinical manifestations were significantly associated with intestinal parasitic infections, while clinical manifestation was the only factor associated with S. aureus infection.
 Conclusion: The present study indicates a high prevalence of pathogenic micro-organisms among male food handlers which highlight the important role of food handlers in the spread and transmission of foodborne infections, and thus requires more attention.

Faecal carriage of multi-drug resistant Enterobacteriaceae in hospitalized children at University Teaching Hospital Sylvanus Olympio of Lomé, Togo

Background: High prevalence of infections and associated antibiotherapy may put children at increased risk for development of multidrug-resistance (MDR), mostly to bacterial infections. The objective of this study therefore was to determine the prevalence of gastrointestinal carriage of MDR Enterobacteriaceae among hospitalized children in the Paediatric department of Sylvanus Olympio University Hospital, Lomé, Togo.Methodology: A descriptive cross-sectional study was carried out on randomly selected hospitalized children in the Paediatric wards of the hospital from November 03 to November 10, 2020, after obtaining informed consent from their parents/guardians. Rectal swabs and stool samples were collected from each participant and cultured for isolation of members of the family Enterobacteriaceae on Hektoen enteric agar containing 4 µg/L cefotaxime, which was incubated aerobically at 37oC for 24 hours. The isolates were identified using in-house biochemical tests. Antibiotic susceptibility test (AST) of each isolate to a panel of antibiotics including ertapenem and imipenem was done by the disc diffusion method and interpreted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints version 2020 V.1.1. ESBL production was detected by the double-disc synergy test of amoxicillin and clavulanic acid, and resistance to carbapenem was inferred by resistance to ertapenem and imipenem discs in the AST. Multi-drug resistance (MDR) was defined as resistance to at least three families of antibiotics. Statistical analysis of data was carried out on Excel 2010 and EPI INFO 7.2 and p value < 0.05 was considered to be statistical significance. Results: A total of 70 hospitalized children during the study period were randomly recruited with an average age of 4 years 3 days and a range of 1 day to 18 years. The male gender was predominant (54.3%) with a M: F ratio of 1.2. Samples were culture positive in 85.7% (60/70) and a total of 72 species of Enterobacteriaceae were isolated in 93.3% (56/60) of these cultures. Escherichia coli was the most frequently isolated species(56.9%, 41/72). More than 90% (65/72) of the isolates were resistant to ampicillin, 58.3% (42/72) to third generation cephalosporins, 59.7% (43/72) to fourth generation cephalosporins, 43% (31/72) to amino-glycosides, 55.6% (40/72) were multi-drug resistant, 48.6% (35/72) were ESBL-producing strains, and 6.9% (5/72) were carbapenem resistant. Eighty-three percent (29/35) of ESBL-producing and all the carbapenem resistant isolates (5/5) were recovered from children on antibiotic therapy. The prevalence of ESBL-producing phenotypes among culture-positive children on antibiotic treatment (72.5%, 29/40) was significantly higher than among culture-positive children not on antibiotic treatment (20.0%, 4/20), indicating that antibiotic therapy was significantly associated with carriage of MDR isolates (OR=10.545, 95% CI=2.882-38.590, p=0.0002). Conclusion: The high faecal carriage rate of MDR Enterobacteriaceae, which are all ESBL-producing strains, in this study is worrying. There is urgent need to develop measures to monitor and limit the spread of these MDR organisms in children and the community in Togo.

Human and Companion Animal Proteus mirabilis Sharing

Proteus mirabilis is an important pathogen that is associated with urinary tract infections. This study aims to determine the colonization and sharing of P. mirabilis between healthy companion animals and humans that are living together and to evaluate the clonal relatedness of the fecal and clinical stains. Eighteen households (24 humans, 18 dogs, 8 cats) with at least one human–animal pair were studied. Fecal samples were plated onto MacConkey and Hektoen agar and P. mirabilis PFGE analysis (NotI; Dice/UPGMA; 1.5% tolerance) was conducted for the households with multiple positive participants. Antimicrobial-resistance was tested according to CLSI. The fecal P. mirabilis pulse-types were compared with uropathogenic clinical strains (n = 183). Forty-nine P. mirabilis were isolated from eight households. The percentage of colonization in the dogs (44.4%, n = 8/18) was significantly higher (p = 0.0329) than in the humans (12.5%, n = 3/24). Three households had multiple colonized participants. One human–dog pair shared related P. mirabilis strains, which clustered with a clinical strain of animal origin (82.5%). One fecal P. mirabilis strain, from a dog, clustered with two human community-acquired clinical strains (80.9%, 88.9%). To our knowledge, this is the first report of dogs and humans living in close contact and sharing related P. mirabilis strains. The high frequency of colonization in the dogs underlines their possible role as P. mirabilis reservoirs for humans and other dogs.

Bacteriological assessment of water from an Eastern Amazon river: challenges in ensuring basic sanitary coverage in riverside communities

This study aimed to analyze the water quality of a river in the Eastern Amazon and relate the results obtained with the lack of basic sanitation in the region. Two samples were collected from strategic points of the river and were submitted to the collimetry technique with multiple tubes to calculate the most probable number (MPN) of thermotolerant coliforms present in the water. The samples were then seeded on CLED and Hektoen agar and analyzed in a mass spectrophotometer for final identification of microorganisms. A high number of thermotolerant coliforms was detected, in addition to bacteria of clinical importance, such as Pseudomonas aeruginosa, Shigella spp. and Cronobacter sakazakii. The lack of basic sanitation in the community surrounding the river is the main cause for the significant number of thermotolerant coliforms, demonstrated by the discrepancy in the MPN between samples 1 and 2. The difficulties in guaranteeing basic sanitation in the Amazon are highlighted and the need to implement public policies and carry out health surveillance studies in these populations is reinforced.

Faecal carriage of extended-spectrum beta-lactamase-producing Enterobacteriaceae in healthy volunteers and hospitalized patients in Ouagadougou, Burkina Faso: prevalence, resistance profile, and associated risk factors

Background: Extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) are a serious challenge to patients’ treatment. The aim of this study is to determine the prevalence of ESBL-PE, investigate the associated resistance, and analyze the associated risk factors for acquisition of ESBL-PE.Methodology: A cross-sectional study was conducted on healthy volunteers and inpatients. After obtaining informed consent, rectal swabs were collected from each participant for isolation of Enterobacteriaceae on Hektoen enteric agar containing 4µg/L cefotaxime. The Enterobacteriaceae isolates were identified using biochemical tests and ESBL production was confirmed by the double-disc synergy test of amoxicillin and clavulanic acid. Antibiotic susceptibility test of each isolate was done by the disc diffusion method and interpreted using the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) clinical breakpoints version 5.0.Results: During the study period, prevalence of faecal ESBL-PE among the study participants was 54.5% (103/189); 53.5% among healthy volunteers and 55.7% among inpatients (p=0.87). The major ESBL-PE isolates was Escherichia coli (71%) followed by Klebsiella pneumoniae (16%). The isolates in hospitalized patients were resistant to norfloxacin (84.2%), cotrimoxazole (89.5%), and gentamicin (7.0%). The isolates from healthy volunteers were resistant to norfloxacin (86.2%), cotrimoxazole (82.8%), and gentamicin (1.7%).Gender, age, and previous antibiotic use were not significantly associated with carriage of ESBL-PE (p=0.51).Conclusion: The high prevalence of ESBL-PE in this study is worrying. There is an urgent need to develop measures to monitor and limit the spread of these multidrug-resistant organisms in healthcare facilities and the community in Burkina Faso.
 Keywords: faecal carriage, ESBL-PE, healthy volunteers, inpatients, Burkina Faso

Outer membrane proteins (OMPs) profiling of a field isolate of Salmonella Typhimurium: Isolation and its characterization

Salmonella Typhimurium is a significant zoonotic pathogen affecting human and animal health. In the present study, a S. Typhimurium isolate, previously isolated from poultry samples was revived and re-confirmed as S. Typhimurium by isolation in Hektoen enteric agar followed by molecular detection. PCR with the stn gene, his J gene and Typh gene primers revealed the specific amplicon of size 617 bp, 496 bp and 402 bp respectively. Antibiotic sensitivity pattern of the isolate was also determined. Isolate was then cultured in LB broth in bulk and outer membrane proteins (OMPs) were isolated by ultracentrifugation. The OMPs were successfully isolated and confirmed by SDS-PAGE analysis. The band pattern revealed nine major bands ranging from 11-90 kDa.

Türkiye’de İlk Defa Saptanan Gıda Kaynaklı Vibrio Parahaemolyticus Olguları*

ABSTRACT Vibrio parahaemolyticus (V.parahaemolyticus) is detected in many parts of the world. It is one of the most common causes of food-borne infections in Asian countries and Japan, and is usually seen as minor outbreaks involving less than ten cases. In this study, it is aimed to investigate V.parahaemolyticus in diarrhea cases in our laboratory in order to draw attention to the possible cases of this agent due to the increase in the consumption of shellfish. In the period of July-August 2018; patients who applied to the emergency service of our hospital with gastrointestinal tract infection symptoms following seafood consumption were investigated by stool microscopy and culture as part of routine procedures. Stool samples were cultured on Hektoen enteric agar, MacConkey agar, and sheep blood agar and were incubated at 37°C for 24 hours. After the incubation period, lactose negative and oxidase-positive colonies were identified by classical biochemical tests, VITEK 2 and MALDI-TOF MS (bioMérieux, France). In seven patients aged between 12-59, clinical symptoms associated with gastroenteritidis started after consuming stuffed mussels in four, eating fish in one, and in a patient after consuming fast food. One patient could not be contacted. In the microscopic examination of the macroscopically watery and mucous stool samples, abundant leukocytes in all samples, and abundant erythrocytes in addition to leukocytes in one sample were seen. The bacteria grown in culture were identified as V.parahaemolyticus by conventional methods and automated systems, Vitek 2 with 96 % and MALDITOF MS with 99 % accuracy. The results were also confirmed by the General Directorate of Public Health, National Enteric Pathogens Reference Laboratory by conventional methods, API 20 E and MALDI-TOF MS (BrukerDaltonics, USA). It should be kept in mind that V.parahaemolyticus can be isolated as a cause of gastroenteritis in diarrhea cases during the summer months, especially in the presence of a history of seafood consumption, and further investigations should be performed in this direction.

Performance evaluation of a selective-enrichment-isolation protocol for Salmonella enterica from seafood

In this study using 57 finfish samples of marine origin, selective enrichment in Rappaport-Vassiliadis (RV) broth followed by isolation on the Hektoen enteric agar (HEA) yielded 50 (53.2%) of 94 isolates. The results suggest RV-HEA as the most suitable media combination for the recovery of Salmonella from tropical seafood.

Chemical and Microbiological Properties of Kefir Produced by Kefir Grains in Raw and Pasteurized Cow’s Milk

The traditional production of kefir uses raw milk as a fermentation substrate which is not acceptable due to food safety issues. However, kefir grains were reported to have antimicrobial properties. Hence, this study determined if kefir grains inhibited certain spoilage and pathogenic microorganisms by comparing the chemical and microbiological properties of the initial substrates: raw milk (RM) and pasteurized milk (PM) to the final products: raw milk kefir (RMK) and pasteurized milk kefir (PMK). Both final products had a significant decrease in fat, moisture, and pH, and a significant increase in protein, total solids, and titratable acidity than RM and PM, respectively. Total solids, titratable acidity, pH, total alcohol, and ethanol were significantly higher in PMK than RMK. RMK had a significantly lower coliform count than RM while both RMK and PMK had significantly higher lactic acid bacteria, yeast and mold count than RM and PM, respectively. Kefir grains’ microbial inhibiting activity was examined if plates were positive or negative against spoilage and pathogenic microorganisms. Escherichia coli-positive plates in Levine’s eosin methylene blue agar decreased in RMK. Salmonella spp.-positive plates in bismuth sulphite agar (BSA), Hektoen enteric agar, and xylose lysine deoxycholate agar decreased in RMK and PMK except for RMK in BSA. Staphylococcus aureus-positive plates in Baird-Parker agar decreased in RMK. RMK and PMK attained the kefir’s standard values for the chemical composition, lactic acid bacteria, yeast and mold count. Nonetheless, the mere presence of spoilage and pathogenic microorganisms in the final products made it unsafe for consumption.

Extended Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae from Broiler Liver in the Center of Algeria, with Detection of CTX-M-55 and B2/ST131-CTX-M-15 in Escherichia coli.

This study aimed to determine the prevalence and diversity of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistant (MDR) Escherichia coli and Klebsiella pneumoniae isolates from 136 broiler livers randomly purchased in 136 retail markets in Djelfa (Algeria). Isolation was performed on Hektoen agar and bacterial identification was carried out by API20E system and Maldi-TOF-MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). Antimicrobial susceptibility was tested by the disk diffusion and agar dilution methods. Detection of ESBLs and other resistance and integron genes, phylogenetic grouping, and molecular typing was performed by PCR and sequencing. Seventy-eight isolates (one per positive sample) were recovered: 73 E. coli and 5 K. pneumoniae. Among E. coli, 86.3% of isolates were MDR. ESBL activity was revealed in eight E. coli and five K. pneumoniae isolates (rates of 5.9% and 3.7% in analyzed samples, respectively). ESBL genes detected among E. coli were as follows (number of isolates): blaCTX-M-15 (3), blaCTX-M-1 (3), blaCTX-M-55 (1), and blaSHV-12 (1); all ESBL-producing K. pneumoniae isolates carried the blaCTX-M-15 gene. ESBL-producing E. coli isolates were assigned to lineages (phylogroup/sequence type and number of isolates in parenthesis): A/ST48 (1), B1/ST6448 (1), B1/ST5087 (3), B1/ST23 (1), and B2/ST131 (two blaCTX-M-15 E. coli isolates). K. pneumoniae isolates were ascribed to sequence types ST2010 and ST3483. Regarding the 65 non-ESBL E. coli isolates, the most observed resistance genes were as follows: tet(A) (75%), blaTEM (57.1%), and sul2 (43.5%). Class1 integrons were revealed in seven non-ESBL E. coli isolates (10.7%) and two gene-cassette arrays were identified: dfrA1 and aadA1+dfrA1. Our study provides evidence that broiler-derived food from Center of Algeria constitutes a source of ESBL and/or MDR-producing Enterobacteriaceae, with detection of relevant ESBL genes and epidemic clones.

Prevalence and antimicrobial susceptibility patterns of Salmonella and Shigella isolates among children aged below five years with diarrhea attending Robe General Hospital and Goba Referral Hospital, South East Ethiopia

BackgroundDiarrheal diseases are responsible for high level of morbidity and mortality, particularly in children below 5 years. Salmonella and Shigella spp. are pathogenic microbes responsible for the major diarrheal associated mortality. The purpose of this study was to determine the prevalence, factors associated with Salmonella and Shigella isolates infections and their antimicrobial susceptibility patterns among diarrheic children aged below 5 years attending BRGH and GRH, Ethiopia.MethodsA health institution based cross-sectional study was conducted from April to July 2016. One stool samples was collected from 422 diarrheic children under the ages of five and were cultured on to Hektoen Enteric (HE) and Salmonella-Shigella agar. Isolation identification of the Salmonella and Shigella isolates were conducted using standard bacteriological methods. Antibiotic susceptibility was done by Kirby–Bauer disk diffusion method. The isolates were defined as multidrug resistant if it was resistant to two or more antimicrobial agents. Descriptive statistics were employed and logistic regression models were constructed to determine factors associated with Shigella/Salmonella prevalence.ResultsThe prevalence of Salmonella and Shigella isolates were 6.9 and 4.3%, respectively. Children aged between 1 to 3 years were significantly associated with Salmonella infection [AOR = 19.08, 95% CI (2.68–135.86)]. The odd of prevalence of Salmonella/Shigella isolates was significantly associated with absence of latrine, absence of hand washing after latrine, and in unimmunized children in adjusted odd ratio. Unimproved water sources and hand washing before meal had also higher odd of prevalence although the difference was not significant. All Salmonella and Shigella isolates were resistant to amoxicillin (100%). In addition, all Shigella isolates were completely resistant to chloramphenicol, and tetracycline, and were multidrug resistant. However, all Salmonella and Shigella isolates were susceptible to ciprofloxacin and ceftriaxone.ConclusionThere was a relatively low prevalence of Salmonella and Shigella species in the study areas and were significantly associated with lack of personal hygiene and environmental sanitation. There were also higher drug resistance and multidrug resistant pattern. Personal hygiene and environmental sanitation, including access to latrine and supply of safe drinking water are suggested. Checking susceptibilities of Shigella and Salmonella isolates causing diarrhea is also suggested.

Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella spp. in free-ranging waterfowl from Entre Rios, Argentina.

The present study was conducted to estimate the apparent prevalence of Salmonella spp. in free-ranging waterfowl that inhabitant Entre Ríos, Argentina, determine the antimicrobial resistance of the isolated, and compare the performance of two selective plating media used for Salmonella isolation. Five hundred ninety nine free-living waterfowl were sampled one time by cloacal swab from April 2014 to July 2016. Only 6 samples from waterfowl belonged to all counties sampled were positive to Salmonella spp., so the apparent prevalence was 1%. Four serovars were isolated (Salmonella ser. Typhimurium, S. ser. Schwarzengrund, S. enterica subsp. I [4,12: i: -], S. enterica subsp. IIIb [60: r: e, n, x, z15]), which were susceptible to 15 antibiotics tested and resistant to erythromycin. Furthermore, some strains showed an intermediate resistant to neomycin, ciprofloxacin and/or streptomycin. The multiple antibiotic resistances index was 0.05. For Hektoen enteric agar and Salmonella Shigella agar, the relative accuracy, sensitivity, specificity, positive predictive value, and negative predictive value did not show any difference between them. The agreement was good between these two plating-media and the difference between these plating-media was not statistically significant. The low prevalence of Salmonella spp. in waterfowl in Entre Rios should not be discounted, since Salmonella ser. Typhimurium was the most prevalent serovar and some free-ranging waterfowl species studied can migrate from/to different countries, increasing the possibility to cross-contaminated Salmonella to resident or other migrant birds.

A Study on Foodborne Bacterial Cross-Contamination During Fresh Chicken Preparation

Background: Cross-contamination of foodborne pathogens from undercooked poultry meat to ready-to-eat food has been shown to be responsible for a number of foodborne disease outbreaks. Various studies have indicated that bacterial cross-contamination occurs during food preparation where bacteria present on food contact other surfaces and cause illness.Objectives: This study evaluated the ability of bacteria to survive and cross-contaminate other foods during the preparation of fresh chicken. Salmonella spp. cross-contamination from chicken to cucumber and utensils under various food handling scenarios was determined.Methods: Two scenarios were tested: in scenario 1, cutting board and knife used for cutting chicken without washing step were sampled. In scenario 2, cutting board and knife was washed with tap water separately after cutting chicken, and subsequently used for cutting cucumber. In scenario 1, chicken, cutting board, knife, and hands were sampled, and in scenario 2, cucumber was tested. Fluorescent in situ hybridization (FISH) method, using published Salmonella specific gene probes was used for Salmonella detection in samples taken from cross-contamination scenarios. A culture-based detection by Hektoen enteric agar was used for the confirmation of Salmonella species.Results: All the samples analyzed were found to be positive for Salmonella spp. with different contamination levels. These results were further confirmed by culture based method. In scenario 1, Salmonella spp. was detected by Sal-1 and Salm-63 oligonucleotide probes in all four samples (chicken, cutting board, knife and hands). A high contamination level was observed in chicken samples in comparison to samples collected from cutting board, knife and hands. In scenario 2, Salmonella spp. was detected by Sal-1 and Salm-63 oligonucleotide probes in the cucumber with very low contamination level. Salmonella Enterica was also detected by Sal-3 and Sapath-3 in both scenarios but the contamination level was not high as compared to Salmonella spp.Conclusion: In conclusion, Salmonella spp. cross-contamination during fresh chicken preparation to read-to-eat-food (cucumber) was confirmed by this study. The experimental data obtained in this study clearly suggest that it is extremely difficult to prevent the spread of Salmonella spp. during the preparation of raw poultry-based meals. Therefore, extreme precautions such as proper cleaning and sanitization of utensils, equipment and surfaces should be carefully followed during the preparation of fresh poultry meat-based food items.

Construction of stable fluorescent laboratory control strains for several food safety relevant Enterobacteriaceae

Using naturally-occurring bacterial strains as positive controls in testing protocols is typically feared due to the risk of cross-contaminating samples. We have developed a collection of strains which express Green Fluorescent Protein (GFP) at high-level, permitting rapid screening of the following species on selective or non-selective plates: Escherichia coli O157:H7, Shigella sonnei, S. flexneri, Salmonella enterica subsp. Enterica serovar Gaminera, S. Mbandaka, S. Tennesse, S. Minnesota, S. Senftenberg and S. Typhimurium. These new strains fluoresce when irradiated with UV light and maintain this phenotype in absence of antibiotic selection. Recombinants were phenotypically equivalent to the parent strain, except for S. Tennessee Sal66 that appeared Lac− on Xylose Lysine Deoxycholate (XLD) agar plates and Lac+ on Mac Conkey and Hektoen Enteric agar plates. Analysis of closed whole genome sequences revealed that Sal66 had lost one lactose operon; slower rates of lactose metabolism may affect lactose fermentation on XLD agar. These fluorescent enteric control strains were challenging to develop and should provide an easy and effective means of identifying cross-contamination.

Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella in backyard chickens from Entre Rios, Argentina.

This study was conducted to estimate the apparent prevalence of Salmonella spp. in birds kept under backyard system in Entre Ríos, Argentina, and determine the performance of two selective plating media used for Salmonella isolation, and the antimicrobial resistance of the isolated. Also, the association of farms characteristics with Salmonella presence was evaluated. A total of 657 backyard chickens and 15 gooses were sampled one time by cloacal swab, belonging to 51 and one family farms, respectively, and four counties in Entre Rios state from April 2014 to May 2015. Only four samples from backyard chickens belonged to three family farms from Uruguay County were positive to Salmonella spp., so the apparent prevalence was 0.6% for this kind of chicken. Four serovars were isolated (Salmonella ser. Lille, S. ser. Newport, S. ser. Enteritidis and S. ser. Rissen), which were susceptible to all antibiotics tested with the exception of erythromycin. For Hektoen enteric agar and brilliant green agar, relative specificity and positive predictive value were 1, and the relative sensitivity and negative predictive value did not show any difference between them. The agreement was very good between these two plating media. None of the variables studied could be selected to calculate the risk factors associated with Salmonella isolation because p>.15. Although the prevalence of Salmonella spp. is low in backyard birds in Entre Rios, the presence of S. ser. Enteritidis should not be discounted, because it is found in the county that concentrates a large population of intensive poultry production in the state.