Evaluating methods for detecting Escherichia albertii in chicken meat

Author(s):  
Sakura Arai ◽  
Kayoko Ohtsuka ◽  
Noriko Konishi ◽  
Kenji Ohya ◽  
Takayuki Konno ◽  
...  

Escherichia albertii is an emerging foodborne pathogen. The source of infection in most foodborne outbreaks is unknown, as it is difficult to isolate E. albertii from suspected foods or water. E. albertii has a broad host range among birds and can be isolated from chicken meat. In this study, PCR assay, enrichment and isolation conditions for detecting E. albertii in chicken meat were evaluated. The growth of 48 E. albertii strains isolated in Japan between 1994 and 2018 was evaluated in modified EC broth (mEC) and mEC supplemented with novobiocin (NmEC) and on different media containing carbohydrates. In addition, the enzyme for nested PCR, the enrichment condition, the most probable number (MPN) method, and agar media were also evaluated for chicken meat. To distinguish E. albertii from presumptive non-E. albertii bacteria, desoxycholate hydrogen sulfide lactose agar (DHL), MacConkey agar (MAC), and these agars supplemented with rhamnose and xylose (RX-DHL and RX-MAC, respectively) were used. All E. albertii strains grew in mEC and NmEC at both 36°C and 42°C and did not utilize rhamnose, sucrose, or xylose. Both the first PCR and nested PCR, using TaKaRa Ex Taq which was 10–100 times superior to the other enzymes, showed positive results in enrichment culture of 25 g of chicken meat inoculated with >20 CFU of E. albertii in mEC and NmEC at 42°C for 22 ± 2 h. Thus, the first PCR was sensitive enough to detect E. albertii in chicken meat. The MPN values in mEC and NmEC were 0.5- and 2.3-fold of inoculated bacterial concentration, respectively. E. albertii in chicken meat was more efficiently isolated with enrichment in NmEC (70.1-100%) and plating onto RX-DHL (85.4%) and RX-MAC (100%) compared to enrichment in mEC (53.5-83.3%) and plating onto DHL (70.1%) and MAC (92.4%), respectively. Thus, optimized conditions for the surveillance of E. albertii contamination in food and investigations of E. albertii outbreaks, including the infectious dose, were clarified.

Author(s):  
Sakura Arai ◽  
Satoko Yamaya ◽  
Kayoko Ohtsuka ◽  
Noriko Konishi ◽  
Hiromi Obata ◽  
...  

Escherichia albertii  is an emerging foodborne pathogen. Owing to its distribution in river water,  it is important to determine the presence of  E. albertii  in aquaculture-related foods. In this study, we investigated the distribution of  E. albertii  in retail oyster samples.  A total of  427 raw oyster samples (385 Pacific oysters, and 42 Japanese rock oysters) were enriched in  modified Escherichia coli  broth (mEC) or mEC supplemented with novobiocin (NmEC) at 42 °C. The cultures were used for  E. albertii -specific nested PCR assay, as well as for  E. albertii  isolation using  deoxycholate hydrogen sulfide lactose agar  (DHL), DHL supplemented with rhamnose and xylose (RX-DHL), and MacConkey agar supplemented with rhamnose and xylose (RX-MAC). The population of  E. albertii  in nested PCR-positive samples was  determined using the  most probable number  (MPN) method.  E. albertii  isolates were subjected to biochemical and genetic characterization.  E. albertii   was detected in 5 of 315 (1.6%) Pacific oyster samples  (one piece each), 2 of 70 (2.9 %)  Pacific oyster samples  (25 g each), and 2 of 42 (4.8 %) Japanese rock oyster samples  procured from four geographically distant regions. A total of 64  E. albertii  strains were isolated from eight of the nine nested PCR assay-positive oyster samples, and  the MPN value was under the detection limit (< 3 MPN/10 g).  A specific season or month for detecting  E. albertii  was not observed in this study, suggesting that the pathogen is present in seawater.   All the  E. albertii  isolates, except one, were positive for the virulence factor  eae,  indicating that these isolates have  the potential to infect humans.


1999 ◽  
Vol 122 (2) ◽  
pp. 185-192 ◽  
Author(s):  
J. TUTTLE ◽  
T. GOMEZ ◽  
M. P. DOYLE ◽  
J. G. WELLS ◽  
T. ZHAO ◽  
...  

Between November 1992 and February 1993, a large outbreak of Escherichia coli O157[ratio ]H7 infections occurred in the western USA and was associated with eating ground beef patties at restaurants of one fast-food chain. Restaurants that were epidemiologically linked with cases served patties produced on two consecutive dates; cultures of recalled ground beef patties produced on those dates yielded E. coli O157[ratio ]H7 strains indistinguishable from those isolated from patients, confirming the vehicle of illness. Seventy-six ground beef patty samples were cultured quantitatively for E. coli O157[ratio ]H7. The median most probable number of organisms was 1·5 per gram (range, <0·3–15) or 67·5 organisms per patty (range, <13·5–675). Correlation of the presence of E. coli O157[ratio ]H7 with other bacterial indicators yielded a significant association between coliform count and the presence of E. coli O157[ratio ]H7 (P=0·04). A meat traceback to investigate possible sources of contamination revealed cattle were probably initially colonized with E. coli O157[ratio ]H7, and that their slaughter caused surface contamination of meat, which once combined with meat from other sources, resulted in a large number of contaminated ground beef patties. Microbiological testing of meat from lots consumed by persons who became ill was suggestive of an infectious dose for E. coli O157[ratio ]H7 of fewer than 700 organisms. These findings present a strong argument for enforcing zero tolerance for this organism in processed food and for markedly decreasing contamination of raw ground beef. Process controls that incorporate microbiological testing of meat may assist these efforts.


1993 ◽  
Vol 56 (1) ◽  
pp. 62-65 ◽  
Author(s):  
ANGELA CÔRREA FREITAS ◽  
MARLY PAIVA NUNES ◽  
ARLETE MOREIRA MILHOMEM ◽  
ILVAN DELGADO RICCIARDI

A total of 35 samples (1000 ml each) of pasteurized milk and 25 samples (100 g each) of white cheese purchased at supermarkets in Rio de Janeiro were analyzed for the presence of Aeromonas. Strains of Aeromonas were isolated from 28.5% of pasteurized milk and 32% of white cheese samples. Standard Plate counts in the pasteurized milk samples ranged from 7.2 × 10* to 2.5 × 105 CFU/ml. Total and fecal coliform counts in white cheese samples ranged from 1.9 × 10* to 2.4 × 105 most probable number per g and 3.2 × 102 to 1.2 × 105 most probable number per g, respectively. It was possible to identify Aeromonas caviae (58.9%), Aeromonas hydrophila (12.8%), and Aeromonas schubertii (2.5%) among the cultures isolated from pasteurized milk samples. Twenty-five percent of the strains could only be classified as Aeromonas spp. In white cheese samples, unclassified strains were the most frequent isolates (61.5%) followed by A. hydrophila (26.9%), A. caviae (7.6%) and Aeromonas sobria (3.8%). Only strains of A. hydrophila and A. sobria showed high rate of positive results when tested for the production of hemolysin, cytotoxin, and staphylolytic activity. Heat-stable enterotoxin and autoagglutination test did not correlate as virulence factors. The presence of Aeromonas species in refrigerated food samples suggests that this microorganism could be a potential foodborne pathogen, and dairy products may represent an important vehicle of its transmission.


Food Research ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 982-990
Author(s):  
Ubong Anyi ◽  
C.Y. New ◽  
L.C. Chai ◽  
Y.Y. Loo ◽  
Nor Khaizura M.A.R. ◽  
...  

Bacillus cereus is a major foodborne pathogen of great concern to the dairy industry owing to its resilient spores as well as the adverse effect of its toxins. At present, there is no informational study available to solve or pinpoint the UHT chocolate milk contamination issue in Malaysia. This work aimed to investigate the prevalence and contamination level of B. cereus s.l. in UHT chocolate milk and to suggest the appropriate solution for the issue. In the present study, B. cereus s.l. prevalence and contamination level in individually packed UHT chocolate milk from processing factories was evaluated. The prevalence and concentration of B. cereus s.l. were determined via MPN-PCR (Most Probable Number-Polymerase Chain Reaction) assay. Results showed that 31.11% from 220 of UHT chocolate milk tested contained Bacillus spp.; of this Bacillus spp. positive samples, 24.30% were also positive for B. cereus s.l. with concentration ranging from less than 3 to more than 1100 MPN/mL. Findings from this study highlighted the possibility of UHT chocolate milk as a potential source of B. cereus s.l. infection. Therefore, findings emphasized the needs to revise, monitor and improve UHT sterilization process to reduce infection risk. Furthermore, it is also essential to maintain the hygiene to minimize initial microbial load and contamination of UHT chocolate milk, beginning from production to retail.


2017 ◽  
Vol 80 (5) ◽  
pp. 814-818 ◽  
Author(s):  
Angela Catford ◽  
Kyle Ganz ◽  
Sandeep Tamber

ABSTRACT A significant data gap exists with respect to the levels of pathogens in foods implicated in foodborne outbreaks. These data are essential for the quantification of pathogen exposure via the ingestion of contaminated food. Here we report the levels of the foodborne pathogen Salmonella in comminuted raw chicken products that had been breaded and then frozen. The products investigated were collected during four food safety investigations of foodborne outbreaks that occurred in Canada from 2014 to 2016. Most-probable-number (MPN) distribution analysis of the food samples revealed Salmonella levels of 0.0018 to 3 MPN/g, which is equivalent to 1 MPN per 0.33 to 556 g of product. These data suggest low levels of Salmonella may be associated with foodborne outbreaks.


2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiaoke Xu ◽  
Jianheng Cheng ◽  
Qingping Wu ◽  
Jumei Zhang ◽  
Tengfei Xie

Abstract Background Vibrio parahaemolyticus is a major foodborne pathogen, particularly in Asian countries. Increased occurrence of outbreaks of V. parahaemolyticus gastroenteritis in China indicates the need to evaluation of the prevalence of this pathogenic species. V. parahaemolyticus distribution in shellfish from the eastern coast of China has been reported previously. However, to date, the prevalence of V. parahaemolyticus in retail aquatic products in North China has not been determined. To investigate the prevalence of V. parahaemolyticus in aquatic products in North China, 260 aquatic product samples were obtained from retail markets in 6 provinces of North China from November to December in 2012 and July to August in 2013. Results V. parahaemolyticus was detected in 94 (36.2 %) of the samples by the most probable number method. The density of V. parahaemolyticus ranged from 1.50 to 1100 MPN/g. V. parahaemolyticus was detected at a rate of 50.0 % and 22.7 % in summer and in winter, respectively. The density of V. parahaemolyticus was significantly higher in summer than in winter, with mean levels of 16.5 MPN/g and 5.0 MPN/g, respectively. Among 145 V. parahaemolyticus isolates examined, none of the isolates possessed tdh and trh. In multiplex PCR-based O-antigen serotyping of these 145 isolates, all serotypes, other than O6, O7, and O9, were detected, and serotype O2 was found to be the most prevalent (detected in 54 isolates). The 145 isolates were grouped into 7 clusters by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) at a similarity coefficient of 0.66. The antimicrobial resistance patterns of these 145 isolates to 12 antimicrobial agents revealed that most of the isolates were resistant to streptomycin (86.2 %), while fewer were resistant to ampicillin (49.6 %), cefazolin (43.5 %), cephalothin (35.9 %), and kanamycin (22.1 %). All of the examined isolates were susceptible to azithromycin and chloramphenicol. Conclusions The findings of this study will help in defining appropriate monitoring programs, understanding of the dissemination of antibiotic resistant strains, and providing information for the assessment of exposure to this microorganism at the consumption level.


1982 ◽  
Vol 89 (2) ◽  
pp. 185-190 ◽  
Author(s):  
F. J. Bolton ◽  
P. M. Hinchliffe ◽  
D. Coates ◽  
L. Robertson

SUMMARYA most probable number (MPN) method capable of estimating as few as ten campylobacters per 100 ml of water is described. The method gave results close to those obtained by the viable count method of Miles, Misra & Irwin (1938) with graded suspensions of Campylobacter jejuni. The method was used to test raw water samples: counts were obtained ranging from 10 to 230 campylobacters per 100 ml for 11 of 49 coastal and estuary water samples, and from 10 to 36 campylobacters per 100 ml for 7 of 44 river samples. Campylobacters were isolated from an additional 24 of the ‘negative’ samples by testing 200 ml volumes by glass microfibre filtration and enrichment culture methods. The MPN method should prove to be a useful epidemiological tool particularly suited to the enumeration of campylobacters in particulate fluids.


2021 ◽  
Vol 4 (1) ◽  
pp. 118
Author(s):  
Dhandy Koesoemo Wardhana ◽  
Devi Ayu Safitri ◽  
Suwaibatul Annisa ◽  
Mustofa Helmi Effendi ◽  
Nenny Harijani

Foodborne diseases are diseases transmitted through contaminated food and are one of the main public health problems. The bacteria that usually contaminates chicken meat is Escherichia coli. E. coli contamination in chicken meat can affect consumer health. Chicken meat processing and market conditions affect the level of bacteria contamination. This study aims to measure the contamination of E. coli bacteria in chicken meat in Surabaya's markets. The method which used to count and estimate the number of E. coli bacteria found in chicken meat in this study was Most Probable Number (MPN). The results showed 20 samples (33.3%) from 60 samples gave negative results. This indicated that only 20 samples of chicken meat were safe for consumption because the MPN value is <1 × 101 CFU/g while the remaining 40 samples (66.7%) were not safe for consumption because the MPN value is> 1 × 101 CFU/g. The standard of SNI 3924: 2009 concerning the minimum requirement for the amount of E. coli contamination in chicken meat is 1×101 CFU/g so that the contamination of E. coli which found in chicken meat in Surabaya was high.


Horticulturae ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 42
Author(s):  
Daniel L. Weller ◽  
Lauren Saylor ◽  
Paula Turkon

Although many studies have investigated foodborne pathogen prevalence in conventional produce production environments, relatively few have investigated prevalence in aquaponics and hydroponics systems. This study sought to address this knowledge gap by enumerating total coliform and generic E. coli levels, and testing for Salmonella presence in circulating water samples collected from five hydroponic systems and three aquaponic systems (No. of samples = 79). While total coliform levels ranged between 6.3 Most Probable Number (MPN)/100-mL and the upper limit of detection (2496 MPN/100-mL), only three samples had detectable levels of E. coli and no samples had detectable levels of Salmonella. Of the three E. coli positive samples, two samples had just one MPN of E. coli/100-mL while the third had 53.9 MPN of E. coli/100-mL. While the sample size reported here was small and site selection was not randomized, this study adds key data on the microbial quality of aquaponics and hydroponics systems to the literature. Moreover, these data suggest that contamination in these systems occurs at relatively low-levels, and that future studies are needed to more fully explore when and how microbial contamination of aquaponics and hydroponic systems is likely to occur.


2020 ◽  
Vol 13 (1) ◽  
pp. 184-187 ◽  
Author(s):  
Paul T. Price ◽  
Thomas A. Gaydos ◽  
Roy D. Berghaus ◽  
Virginia Baxter ◽  
Charles L. Hofacre ◽  
...  

Background and Aim: Salmonella Enteritidis (SE) is a significant foodborne pathogen that can often be traced to poultry and poultry products. This study aims to evaluate the ability of three commonly used non-antimicrobial feed additives in reducing the amount of SE in the ceca of laying type pullets. Materials and Methods: On day 0, 60 Hy-Line Brown pullets aged 9 weeks were allocated to individual cages in 15 replicate blocks of four pens. Pullets were administered a mash feed provided ad libitum without supplementation (control) or with dietary supplementation of 454 g/ton yeast cell wall (YCW), or 454 g/ton Bacillus spp. probiotic, or 1133 g/ton yeast culture (YC). On day 3 of the trial, all birds were orally administered 3×107 CFU of a nalidixic acid-resistant SE. On day 10, 7 days after inoculation, all birds were humanely euthanized, and the ceca were aseptically removed for analysis. Results: There was no significant difference in the prevalence of SE among treatments. The mean quantity of SE detected in the ceca expressed in log10 most probable number/g was 2.52 in the control, 2.49 in the YCW treatment, 1.73 in the probiotic treatment, and 1.66 in the YC treatment. The reduction between control and probiotic and control and YC was significant (p=0.021). Conclusion: This study demonstrates the ability of the novel probiotic and the YC to reduce the load of SE in layer ceca.


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