Prevalence, Concentrations, and Antibiotic Sensitivities of Salmonella Serovars in Poultry from Retail Establishments in Seattle, Washington

2014 ◽  
Vol 77 (6) ◽  
pp. 885-893 ◽  
Author(s):  
E. MAZENGIA ◽  
M. SAMADPOUR ◽  
H. W. HILL ◽  
K. GREESON ◽  
K. TENNEY ◽  
...  
Keyword(s):  
Significant Proportion ◽  
Performance Standards ◽  
Production Method ◽  
Immunomagnetic Separation ◽  
Product Type ◽  
Most Probable Number ◽  
Probable Number ◽  
Critical Data ◽  
Data Gaps ◽  
Processed Products

Poultry have been identified as one of the major sources of salmonellosis, with estimates ranging from 10 to 22% of total cases. Despite several advances in the industry and new performance standards, the incidence of salmonellosis in the population has not declined over the last 15 years. Salmonella is pervasive in a wide variety of foods, and thus, estimating its burden resulting from specific food categories has been challenging and plagued with uncertainty due to critical data gaps. The objective of this study was to conduct a year-long market survey (1,322 samples) to help bridge the data gaps on the contamination rates and levels of Salmonella on raw poultry by product type (i.e., breast, thighs, drums, wings, and split breast) and production method (conventional versus organic). The isolates recovered were serotyped and tested for antibiotic sensitivities. A PCR method was utilized for initial screening of samples after an overnight enrichment in tryptic soy broth. Three-tube most-probable-number (MPN) assays and anti-Salmonella immunomagnetic separation methods were utilized to determine the levels of Salmonella and aid with the recovery of Salmonella species, respectively. Eleven percent of the samples were positive for Salmonella. Significant differences in percent positive rates by product type included up to a 4-fold difference in percent positive rates between establishments, ranging from 7 to 31%. Of the samples positive for Salmonella species, 94% had <30 MPN/100 g. Production methods identified as organic or as not using antibiotics had significantly higher rates of recovery of Salmonella. On the other hand, all of the Salmonella isolates that were resistant to two or more antibiotics originated from conventional processing establishments where antibiotics were utilized. In addition, a significant proportion of isolates from conventionally processed products were serotypes clinically relevant to humans.

scholarly journals Comparison of media and methods for countingClostridium perfringensin poultry meat and further-processed products

1980 ◽  
Vol 84 (1) ◽  
pp. 151-158 ◽  
Author(s):  
B. W. Adams ◽  
G. C. Mead
Keyword(s):  
Egg Yolk ◽  
Poultry Meat ◽  
Most Probable Number ◽  
Similar Species ◽  
Good Growth ◽  
Probable Number ◽  
Direct Plating ◽  
Confirmatory Tests ◽  
Processed Products ◽  
Reference Strains

SUMMARYA Most Probable Number (MPN) method involving Differential Reinforced Clostridial Medium followed by streaking on Willis & Hobbs medium was com pared with direct plating of samples on Tryptose-Suiphite-Cycloserine agar with out egg yolk, and two forms of Oleandomycin-Polymyxin-Suiphadiazine-Per fringens agar, one being prepared from a commercial, dehydrated product.With skin samples taken from chicken carcasses at different stages of processing, the three direct plating media gave similar counts ofCl. perfringenswhereas results obtained with the MPN method were consistently lower.Although counts ofCl. perfringensfrom various further processed products were usually < 10/g, the three plating media showed similar specificity for this organism.All media supported good growth of reference strains ofClostridium perfringensbut it was founsi that physiologically similar species, includingCl. absonum, Cl. paraperfringens and Cl. perenne alsogrew uninhibited in these media and produced colonies identical with those ofCl. perfringens, thus indicating the need for confirmatory tests forCl. perfringenswhen examining natural samples.

scholarly journals Evaluation of Culture Methods To Identify Bovine Feces with High Concentrations of Escherichia coli O157

2007 ◽  
Vol 73 (16) ◽  
pp. 5253-5260 ◽  
Author(s):  
J. Trent Fox ◽  
David G. Renter ◽  
Michael W. Sanderson ◽  
Daniel U. Thomson ◽  
Kelly F. Lechtenberg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sensitivity And Specificity ◽  
Immunomagnetic Separation ◽  
Most Probable Number ◽  
Culture Methods ◽  
Potassium Tellurite ◽  
Probable Number ◽  
E Coli ◽  
Concentration Sensitivity ◽  
High Concentrations

ABSTRACT Our objective was to evaluate methods for identifying cattle with high concentrations of Escherichia coli O157 in their feces. In two experiments, feces were collected from cattle orally inoculated with nalidixic acid (Nal)-resistant E. coli O157, and direct plating of diluted feces on sorbitol MacConkey agar with cefixime and potassium tellurite (CT-SMAC) containing Nal was considered the gold standard (GS) method. In experiment 1, methods evaluated were preenrichment direct streak, immunomagnetic separation with most probable number (MPN), and postenrichment direct streak with MPN, all using CT-SMAC. The mean concentration of Nal-resistant E. coli O157 in samples (n = 59) by use of the GS was 3.6 log10 CFU/g. The preenrichment streak detected >3.0 log10 CFU/g samples with a 74.4% sensitivity and 68.8% specificity. Postenrichment direct streak-MPN and immunomagnetic separation-MPN concentrations were correlated significantly with GS concentrations (r = 0.53 and r = 0.39, respectively). In experiment 2 (480 samples), pre- and postenrichment direct streaking performed in triplicate and spiral plating on CT-SMAC were evaluated. For preenrichment streaks, sensitivity was 79.7% and specificity was 96.7% for detecting >3.0 log10 CFU/g when the criterion was positive cultures on at least two plates. For spiral plating at that concentration, sensitivity and specificity were 83.9% and 56.3%, respectively. Postenrichment streaking performed relatively poorly. Triplicate preenrichment streaks of 1:10-diluted feces on CT-SMAC may be useful for identifying cattle shedding high concentrations of E. coli O157. Estimates of sensitivity and specificity enable appropriate application of methods and interpretation of results and may enhance applied research, surveillance, and risk assessments.

An Investigation of Escherichia coli O157 Contamination of Cattle during Slaughter at an Abattoir

2005 ◽  
Vol 68 (3) ◽  
pp. 451-457 ◽  
Author(s):  
NARELLE FEGAN ◽  
GLEN HIGGS ◽  
PAUL VANDERLINDE ◽  
PATRICIA DESMARCHELIER
Keyword(s):  
Escherichia Coli ◽  
Oral Cavity ◽  
Immunomagnetic Separation ◽  
Most Probable Number ◽  
Escherichia Coli O157 ◽  
Probable Number ◽  
Fecal Samples ◽  
E Coli ◽  
Cell Counts ◽  
Carcass Contamination

The extent of contamination with Escherichia coli O157 was determined for 100 cattle during slaughter. Samples from 25 consecutively slaughtered cattle from four unrelated groups were collected from the oral cavity, hide, rumen, feces after evisceration, and pre- and postchill carcass. Ten random fecal samples were collected from the pen where each group of animals was held at the abattoir. E. coli O157 was detected using automated immunomagnetic separation (AIMS), and cell counts were determined using a combination of most probable number (MPN) and AIMS. E. coli O157 was isolated from 87 (14%) of the 606 samples collected, including 24% of 99 oral cavity samples, 44% of 100 hides, 10% of 68 fecal samples collected postevisceration, 6% of 100 prechill carcass swabs, and 15% of 40 fecal samples collected from holding pens. E. coli O157 was not isolated from rumen or postchill carcass samples. E. coli O157 was isolated from at least one sample from each group of cattle tested, and the prevalence in different groups ranged from less than 1 to 41%. The numbers of E. coli O157 differed among the animals groups. The group which contained the highest fecal (7.5 × 105 MPN/g) and hide (22 MPN/cm2) counts in any individual animal was the only group in which E. coli O157 was isolated from carcasses, suggesting a link between the numbers of E. coli O157 present and the risk of carcass contamination. Processing practices at this abattoir were adequate for minimizing contamination of carcasses, even when animals were heavily contaminated with E. coli O157.

scholarly journals Confirming the Presence of Legionella pneumophila in Your Water System: A Review of Current Legionella Testing Methods

2021 ◽  
Author(s):  
James T Walker ◽  
Paul McDermott
Keyword(s):  
Legionella Pneumophila ◽  
Water System ◽  
Culture Method ◽  
Immunomagnetic Separation ◽  
Most Probable Number ◽  
Water Safety ◽  
Probable Number ◽  
Culture Independent ◽  
Multiple Species ◽  
Risk Managers

Abstract Legionnaires’ disease has been recognized since 1976 and Legionella pneumophila, still accounts for more than 95% of cases. Approaches in countries, including France, suggest that focusing risk reduction specifically on L. pneumophila is an effective strategy, as detecting L. pneumophila has advantages over targeting multiple species of Legionella. In terms of assays, the historically accepted plate culture method takes 10 days for confirmed Legionella spp. results, has variabilities which affect trending and comparisons, requires highly trained personnel to identify colonies on a plate in specialist laboratories and does not recover viable-but-non-culturable (VBNC) bacteria. Polymerase chain reaction is sensitive, specific and provides results in less than 24 h and determines the presence/absence of Legionella spp. and/or L. pneumophila DNA. Whilst specialist personnel and laboratories are generally required, there are now on-site PCR options but there is no agreement on comparing genomic units to colony forming units and action limits. Immunomagnetic separation assays are culture-independent, detect multiple Legionella species and results are available in 24 h, with automated processing options. Field-use lateral flow devices provide presence/absence determination of L. pneumophila serogroup 1 where sufficient cells are present, but testing potable waters is problematic. Liquid culture most probable number (MPN) assays provide confirmed L. pneumophila results in 7 days that are equivalent to or exceed plate culture, are robust and reproducible and can be performed in a variety of laboratory settings. MPN isolates can be obtained for epidemiological investigations. This accessible, non-technical review will be of particular interest to building owners, operators, risk managers and water safety groups to make informed decisions to reduce the risk of L. pneumophila.

Development and Validation of a Most-Probable-Number–Immunomagnetic Separation Methodology of Enumerating Escherichia coli O157 in Cattle Feces

2007 ◽  
Vol 70 (5) ◽  
pp. 1072-1075 ◽  
Author(s):  
T. P. STEPHENS ◽  
G. H. LONERAGAN ◽  
W. E. CHANEY ◽  
L. A. BRANHAM ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Immunomagnetic Separation ◽  
Feedlot Cattle ◽  
Most Probable Number ◽  
Escherichia Coli O157 ◽  
Probable Number ◽  
Direct Plating ◽  
Fecal Samples ◽  
E Coli ◽  
The Difference

A method to validate enumeration of Escherichia coli O157 in fecal samples from feedlot cattle was developed in these studies. Due to background flora, bovine fecal sample enumeration cannot be performed by simple direct plating techniques. Known quantities of E. coli O157:H7 were inoculated into feces, and populations were determined by direct plating of the cocktail (studies 1, 2, and 3) and manure and cocktail (studies 4 and 5) mixtures and compared with a most-probable-number (MPN)–immunomagnetic separation (IMS) method. The three-tube MPN combined preenrichment in gram-negative broth with confirmation using IMS. Five separate enumeration studies (study 1, sterile feces inoculated with 102 E. coli O157:H7 per g; study 2, nonsterile feces inoculated with 103 E. coli O157:H7 per g; study 3, nonsterile feces inoculated with 101 E. coli O157:H7 per g; study 4, sterile feces inoculated with 104 streptomycin-resistant E. coli O157:H7 per g; and study 5, sterile feces inoculated with 102 streptomycin-resistant E. coli O157:H7 per g) were conducted. These studies were performed to determine the precision, accuracy, and specificity at low and high levels of pathogen contamination in feces, using direct plating compared with the MPN-IMS methodology tested. There was an overall difference (P &lt; 0.01) between direct plating and MPN-IMS methodologies, but this difference was biologically negligible due to the difference in least-squares means (0.29 ± 0.10) being so low. The direct plating and MPN-IMS methods were correlated (r = 0.93). These results suggest that using the MPN-IMS procedures is an effective method of estimating E. coli O157 populations in naturally infected bovine fecal samples.

Statistical Distributions Describing Microbial Quality of Surfaces and Foods in Food Service Operations

2004 ◽  
Vol 67 (1) ◽  
pp. 162-167 ◽  
Author(s):  
REBECCA MONTVILLE ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Food Service ◽  
Fecal Coliforms ◽  
Most Probable Number ◽  
Microbial Quality ◽  
Statistical Distributions ◽  
Probable Number ◽  
Plate Counts ◽  
Processed Products ◽  
Cutting Boards

Data on the microbial quality of food service kitchen surfaces and ready-to-eat foods were collected over a period of 10 years in Rutgers University dining halls. Surface bacterial counts, total aerobic plate counts, and total and fecal coliform counts were determined using standard methods. Analysis was performed on foods tested more than 50 times (primarily lunch meats and deli salads) and on surfaces tested more than 500 times (36 different surfaces types, including pastry brushes, cutting boards, and countertops). Histograms and statistical distributions were determined using Microsoft Excel and Palisades Bestfit, respectively. All data could be described by lognormal distributions, once data above and below the lower and upper limits of detection were considered separately. Histograms for surfaces counts contained one peak near 1 CFU/4 cm2. Surfaces with higher levels of contamination tended to be nonmetal, with the exception of buffalo chopper bowls, which commonly had high counts. Mean counts for foods ranged from 2 to 4 log CFU/g, with shrimp salad, roast beef, and bologna having higher means. Coleslaw, macaroni salad, and potato salad (all commercially processed products, not prepared in the dining halls) had lowest overall means. Coliforms were most commonly found in sealeg salad (present in 61% of samples) and least commonly found in coleslaw (present in only 7% of samples). Coliform counts (when present) were highest on average in shrimp salad and lowest in coleslaw. Average coliform counts for most products were typically between 1 and 2 log most probable number per gram. Fecal coliforms were not typically found in any deli salads or lunch meats.

scholarly journals Most-Probable-Number Loop-Mediated Isothermal Amplification–Based Procedure Enhanced with K Antigen–Specific Immunomagnetic Separation for Quantifying tdh+ Vibrio parahaemolyticus in Molluscan Shellfish

2014 ◽  
Vol 77 (7) ◽  
pp. 1078-1085 ◽  
Author(s):  
NATSUKO TANAKA ◽  
YOSHITO IWADE ◽  
WATARU YAMAZAKI ◽  
FUMIO GONDAIRA ◽  
VARAPORN VUDDHAKUL ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Lamp Assay ◽  
Immunomagnetic Separation ◽  
Microtiter Plate ◽  
Isothermal Amplification ◽  
Most Probable Number ◽  
Probable Number ◽  
Loop Mediated Isothermal Amplification ◽  
Wide Range ◽  
Thermostable Direct Hemolysin

Although thermostable direct hemolysin–producing (tdh+) Vibrio parahaemolyticus is the leading cause of seafood-borne gastroenteritis, the enumeration of tdh+V. parahaemolyticus remains challenging due to its low densities in the environment. In this study, we developed a most-probable-number (MPN)–based procedure designated A-IS1-LAMP, in which an immunomagnetic separation (IMS) technique targeting as many as 69 established K antigens and a loop-mediated isothermal amplification (LAMP) assay targeting the thermostable direct hemolysin (tdh) gene were applied in an MPN format. Our IMS employed PickPen, an eight-channel intrasolution magnetic particle separation device, which enabled a straightforward microtiter plate–based IMS procedure (designated as PickPen-IMS). The ability of the procedure to quantify a wide range of tdh+V. parahaemolyticus levels was evaluated by testing shellfish samples in Japan and southern Thailand, where shellfish products are known to contain relatively low and high levels of total V. parahaemolyticus, respectively. The Japanese and Thai shellfish samples showed, respectively, relatively low (&lt;3 to 11 MPN/10 g) and considerably higher (930 to 110,000 MPN/10 g) levels of tdh+V. parahaemolyticus, raising concern about the safety of Thai shellfish products sold to domestic consumers at local morning markets. LAMP showed similar or higher performance than conventional PCR in the detection and quantification of a wide range of tdh+V. parahaemolyticus levels in shellfish products. Whereas a positive effect of PickPen-IMS was not observed in MPN determination, PickPen-IMS was able to concentrate tdh+V. parahaemolyticus 32-fold on average from the Japanese shellfish samples at an individual tube level, suggesting a possibility of using PickPen-IMS as an optional tool for specific shellfish samples. The A-IS1-LAMP procedure can be used by any health authority in the world to measure the tdh+V. parahaemolyticus levels in shellfish products.

scholarly journals Enumeration and Survival of Salmonella enterica in Live Oyster Shellstock Harvested from Canadian Waters

2019 ◽  
Vol 83 (1) ◽  
pp. 6-12 ◽  
Author(s):  
SANDEEP TAMBER ◽  
ALEX MONTGOMERY ◽  
KATIE ELORANTA ◽  
ENRICO BUENAVENTURA
Keyword(s):  
Salmonella Enterica ◽  
Most Probable Number ◽  
Oyster Tissue ◽  
Probable Number ◽  
Ambient Temperatures ◽  
Fundamental Information ◽  
Data Gaps ◽  
Contamination Event ◽  
Management Approaches ◽  
The Relationship

ABSTRACT Since 2015, 11 recalls of live oyster shellstock have been issued in Canada due to the presence of Salmonella enterica. Six of those recalls took place in 2018. To understand this increase, fundamental information is needed on the relationship between S. enterica and oysters. The aims of this study were to address important data gaps concerning the levels of Salmonella in naturally contaminated oysters and the ability of this pathogen to survive in live oyster shellstock. Enumeration data were evaluated for five oyster and clam samples collected from the east coast of Canada from 2015 to 2018. The reported levels were &lt;0.0015 to 0.064 most probable number per g of oyster tissue. The S. enterica isolates recovered from these animals belonged to serovars Typhimurium, Infantis, Enteritidis, and I 4,5:i:−. Filter feeding by the oysters was exploited to assess the Salmonella accumulation that would occur following a natural contamination event. Detectable levels of the pathogen were observed after 30 min of exposure and began to plateau at 60 min. A survival study in live oyster shellstock indicated that after 4 days of storage at ambient temperatures, the Salmonella level declined slightly from 4.3 to 3.7 log CFU/g. These data indicate that the levels of Salmonella found in naturally contaminated oysters are low and are not expected to increase between the point of harvest and the point of consumption. The changing ecology of shellfish environments requires continued monitoring and testing to safeguard public health. The data presented here will be useful for the evaluation and design of sampling plans and risk management approaches for the control of Salmonella in live oyster shellstock. HIGHLIGHTS

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