Storage Mycoflora in Sesame Seed Production in Benue State, Nigeria

Sesame (Sesamum indicum) is usually contaminated with many fungi where some of them are mycotoxigenic causing economic and health problems. This study investigated the percentage composition of fungi contamination of sesame seeds in Benue state Nigeria. Using direct plating technique; the study revealed twelve species of fungi contamination in sesame seed obtained in Benue State. The percentage occurrence of fungal isolates shows that Aspergillus flavus and A. niger were found in all the locations and their occurrence was significantly different (P≤0.05). The percentage contamination of Sesame samples collected from Otukpo LGA has the highest fungal (23.35%) contamination and was significantly higher (P≤0.05) from samples of other places whereas Sesame contamination from Gboko was the least with total percentage of (12.05%). In conclusion, considering the benefits of sesame, it is recommended that several treatments should be applied to reduce the levels of contamination in sesame seeds before consumption utilization such as environmental conditions leading to fungal proliferation (a high temperature, humidity, poor soil fertility, drought and insect damage). Also poor harvesting practices, unsuitable storage conditions, improper transportation, marketing and processing should be discouraged.

Comparison of stool samples and rectal swabs with and without pre-enrichment for the detection of third-generation cephalosporin-resistant Enterobacterales (3GCREB)

To establish the optimal detection of third-generation cephalosporin-resistant Enterobacterales (3GCREB), the performance of four different screening methods has been investigated: stool samples without (A) and with (B) pre-enrichment and rectal swabs without (C) and with (D) pre-enrichment were contrasted. Pre-enrichment approaches (B and D) increased the detection of 3GCREB carriers by 29.4% (20/68 3GCREB carriers only found using pre-enrichment, p < 0.0001) compared to direct plating approaches (A and C). Moreover, the study demonstrates a minor advantage of stool samples in contrast to rectal swabs in both cases (with and without pre-enrichment). Registration number: DRKS00022520, 24 July 2020.

#89: Lytic Bacteriophage Against an Emergent Biofilm-Forming Enteroinvasive Escherichia coli

Background Bacteriophage are viruses that infect and parasitize bacteria. In the pre-antibiotic era, phage therapy was one of the few tools available against bacterial infection. After penicillin was discovered, phage therapy fell into disfavor in Western medicine, and its use was mostly limited to medical centers in the Soviet bloc. With current issues on multi-drug resistance, especially of Gram-negative bacteria, there is interest in revisiting phage therapy for use in medical and veterinary practice. This study focuses on the biofilm-forming enteroinvasive Escherichia coli (BF-EIEC) serotype O96:H19. Strain BF-EIEC 52.1 was isolated in a pediatric case–control diarrheal study in Bucaramanga, Colombia, in 2013–2014. This strain is genetically similar to a foodborne outbreak strain isolated in Italy in 2012, and in sporadic outbreaks in the UK, Spain, and Uruguay. BF-EIEC 52.1 produces biofilms in vitro, similarly to enteroaggregative E. coli, and yet invades host cells, similar to enteroinvasive E. coli and Salmonella enterica (J. Iqbal, O. Gómez-Duarte et al., manuscript in preparation), making this a potential emergent pathogen of concern. We hypothesized that lytic bacteriophage derived from wastewater sources are active against BF-EIEC 52.1. Methods Environmental wastewater samples were retrieved from the Amherst, New York, wastewater treatment facility. These were filtered against a 0.2 μm membrane and stored at 4°C. An attempt to isolate phage was done by direct plating over E. coli BF-EIEC 52.1 on solid Luria–Bertani (LB) agar. A second strategy involved enrichment for lytic phage by incubating sample water with BF-EIEC 52.1 in LB broth. Cloning was accomplished by re-filtering the preparation (to remove bacteria), then followed by serial limiting dilution of cell-free filtrate in liquid bacterial culture. Characterization of phage preparations included a demonstration of differential lytic activity against BF-EIEC 52.1 and two unrelated laboratory E. coli strains, DH5α and HB101, in both solid agar and liquid medium. Results Isolation of phage by direct plating was possible, but cloning phages proved difficult. With the alternative strategy, four of six wastewater specimens incubated with BF-EIEC 52.1 in liquid LB showed decreased turbidity compared with sterile water control. All positive specimens proved to have demonstrable lytic activity against host E. coli by plaque formation in solid medium, and in limiting dilution in liquid medium. Thirty-two putative phage preparations were cloned by repeated limiting dilution from an initial 16 independent wells. Of these, 27 preparations showed visible plaques against BF-EIEC 52.1 in solid agar, while 29 and 23 preparations showed plaques against HB101 and DH5α, respectively. All phage preparations inhibited the growth of low-inoculum BF-EIEC 52.1 in liquid medium for &gt;6 hours. Six virus preparations inhibited growth for &gt;72 hours. Conclusions Bacteriophage active against strain BF-EIEC 52.1 were isolated from urban wastewater samples, showing a range of activity against the parental host, as well as unrelated E. coli strains. Further study is needed to demonstrate activity in alternative clinical settings, such as in biofilm-associated infections or in animal models.

Comparison of culture-based strategies for isolating bacteria from the porcine intestine

The isolation of bacteria that represent the diversity of autochthonous taxa in the gastrointestinal tract is necessary to fully ascertain function, but the majority of bacterial species inhabiting the intestines of mammals are fastidious, and thus challenging to isolate. The goal of the current study was to isolate a diverse assemblage of bacteria from the intestine of pigs as a model animal, and to comparatively examine various novel and traditional isolation strategies. Methods used included long-term enrichments, direct plating, a modified Ichip, as well as ethanol and Tyndallization treatment of samples to select for endospore-forming taxa. A total of 234 taxa (91 previously uncultured) comprising 80 genera and seven phyla were isolated from mucosal and luminal samples from the ileum, cecum, ascending colon, and spiral colon removed from animals under anesthesia. The diversity of bacteria isolated from the large intestine was less than detected by next-generation sequence analysis. Long-term enrichments yielded the greatest diversity of recovered bacteria (Shannon’s index [SI] = 4.7). Methods designed to isolate endospore-forming bacteria produced the lowest diversity (SI ≤ 2.7), with Tyndallization yielding a lower diversity than the ethanol method. However, the isolation frequency of previously uncultured bacteria was greatest for ethanol-treated samples (41.9%) and the Ichip method (32.5%). The goal of recovering a diverse collection of enteric bacteria was achieved. Importantly, study findings demonstrate that it is necessary to use a combination of methods in concert to isolate bacteria that are representative of the diversity within the intestines of mammals. IMPORTANCE This work determined that using a combination of isolation methods is necessary to increase the diversity of bacteria recovered from the intestines of monogastric mammals. Direct plating methods have traditionally been used to isolate enteric bacteria, and recent methods (e.g. diffusion methods [i.e. Ichip] or differential isolation of endospore-forming bacteria) have been suggested to be superior at increasing diversity, including the recovery of previously uncultured taxa. We showed that long-term enrichment of samples using a variety of media isolated the most diverse and novel bacteria. Application of the Ichip method delivered similar diversity of bacteria to enrichment and direct plating methods. Methods that selected for endospore-forming bacteria generated collections that differed in composition to other methods with reduced diversity. However, the ethanol treatment frequently isolated novel bacteria. By using a combination of methods in concert, a diverse collection of enteric bacteria was generated for ancillary experimentation.

A Multicenter Proposal for a Fast Tool To Screen Biosecure Chicken Flocks for the Foodborne Pathogen Campylobacter

ABSTRACT The present multicenter study aimed at assessing the performance of air sampling as a novel method for monitoring Campylobacter in biosecure poultry farms. We compared, using a harmonized procedure, the bacteriological isolation protocol (ISO 10272-1:2017) and a real-time PCR method used on air filter samples. Air samples and boot swabs were collected from 62 biosecure flocks from five European countries during the summer of 2019. For air filters, the frequency of PCR-positive findings was significantly higher (n = 36; 58%) than that obtained with the cultivation methods (P < 0.01; standardized residuals). The cultivation protocols (one with Bolton enrichment and one with Preston enrichment) were comparable to each other but returned fewer positive samples (0 to 8%). The association between type of sample and frequency of PCR-positive findings was statistically confirmed (P < 0.01; Fisher´s exact test), although no culture-positive air filters were detected using direct plating. For the boot swabs, the highest number of positive samples were detected after enrichment in Preston broth (n = 23; 37%), followed by direct plating after homogenization in Preston (n = 21; 34%) or Bolton broth (n = 20; 32%). It is noteworthy that the flocks in Norway, a country known to have low Campylobacter prevalence in biosecure chicken flocks, tested negative for Campylobacter by the new sensitive approach. In conclusion, air sampling combined with real-time PCR is proposed as a multipurpose, low-cost, and convenient screening method that can be up to four times faster and four times more sensitive than the current boot-swab testing scheme used for screening biosecure chicken production. IMPORTANCE Campylobacter bacteria are the cause of the vast majority of registered cases of foodborne illness in the industrialized world. In fact, the bacteria caused 246,571 registered cases of foodborne illness in 2018, which equates to 70% of all registered cases in Europe that year. An important tool to prevent campylobacters from making people sick is good data on where in the food chain the bacterium is present. The present study reports a new test method that quadruples the likelihood of identifying campylobacter-positive chicken flocks. It is important to identify campylobacter-positive flocks before they arrive at the slaughterhouse, because negative flocks can be slaughtered first in order to avoid cross-contamination along the production line.

Studies on characteristics of Xanthomonas oryzae isolates associated with Rice crop

Rice Bacterial Leaf Blight (BLB) is considered the most imperative disease among various dangerous maladies of rice in Pakistan. There is no any reliable source of resistance against this disease. Moreover, pathogen has a vast diversity in its population. So, first and most important step for its control is pathogen identification and characterization. Therefore, present studies were carried out for surveillance of disease and to collect disease specimens from Hyderabad and Tando-Muhammad Khan (TMK) Districts. Associated pathogen was isolated from collected samples by direct plating method. Fourteen cultures were purified by streaking method and were characterized on the basis of colony morphology, cell morphology and gram staining. The colonies were found to be large, medium and small. Their shapes were filamentous, irregular and circular. They were found to be raised, undulate, entire and convex showing pale yellow, yellow, off white, reddish and creamy color and surface of most of the colonies was observed to be smooth.