Development of a Selective Broth Medium for the Detection of Injured Campylobacter jejuni by Capacitance Monitoring

2003 ◽  
Vol 66 (10) ◽  
pp. 1752-1755 ◽  
Author(s):  
J. ERIC LINE ◽  
KIRSTEN G. PEARSON
Keyword(s):  
Campylobacter Jejuni ◽  
Rapid Detection ◽  
Basal Medium ◽  
Triphenyltetrazolium Chloride ◽  
Inoculum Level ◽  
Single Strain ◽  
Initial Inoculum ◽  
Medium Components ◽  
Pure Cultures ◽  
The Mean

The purpose of these studies was to develop a conductimetric method for the rapid detection of Campylobacter jejuni. Numerous basal medium components were analyzed to develop a growth-enhancing broth medium for detection of freeze-injured Campylobacter cells using a conductimetric system. The final medium was composed of a modified Campy-Line agar from which the agar and triphenyltetrazolium chloride were removed and the amino acid, l-arginine was added. Pure isolates of C. jejuni. (frozen and thawed to produce stressed cells) were utilized to test the detection methodology. Monitoring of significant changes in the capacitance signal was found suitable for detection of Campylobacter proliferation. Using stressed pure cultures, Campylobacter growth was repeatedly detected at very low inoculum levels (about one cell per well). There was a direct linear relationship between detection times (DTs) and the initial inoculum level. For example, using a single strain, the mean DT (n = 20) at the 10 CFU/ml inoculum level was 28.6 h, with 100% of the inoculated wells detecting. The mean DTs at the 100, 1,000, and 10,000 CFU/ml inoculum levels were 24.9, 21.4, and 17.0 h, respectively. This study demonstrates that conductimetric methods can be utilized for the rapid detection of C. jejuni.

scholarly journals Infection and cross-infection in a Paediatric Gastro-enteritis unit

Curationis ◽  
1989 ◽  
Vol 12 (3/4) ◽  
Author(s):  
Jean Bowen Jones
Keyword(s):  
Nosocomial Infection ◽  
Salmonella Typhimurium ◽  
Campylobacter Jejuni ◽  
Cross Infection ◽  
Enteric Pathogens ◽  
Academic Hospital ◽  
Viral Pathogens ◽  
Contributory Factors ◽  
Shigella Spp ◽  
The Mean

A two month study to investigate the incidence o f nosocomial infection was conducted in a paediatric gastroenteritis ward o f a black academic hospital. Enteric pathogens were identified on admission in 61 (47,2%) o f 129 patients; 56 bacterial and 25 viral. Six per cent o f patients had a combination o f bacterial and viral pathogens. Enteric pathogens most frequently identified on admission were Campylobacter jejuni in 22%, Rotavirus in 19,3%, EPEC in 10,8% and Shigella spp. in 6,9% patients. Twenty six (20%) patients had more than 1 enteric pathogen. The nosocomial infection rate was recorded at 17,1%. EPEC occurred most commonly in 5,3% patients, Salmonella typhimurium in 4,6% and Shigella spp. in 2,3%. Nosocomial infections increased the mean length o f hospital stay from 7,2- 20,2 days. Contributory factors to the spread o f nosocomial infection were the unsatisfactory methods o f bathing patients and giving naso-gastric feeds.

Transfer of Salmonella and Campylobacter from Stainless Steel to Romaine Lettuce†

2003 ◽  
Vol 66 (12) ◽  
pp. 2231-2236 ◽  
Author(s):  
CHRISTINA M. MOORE ◽  
BRIAN W. SHELDON ◽  
LEE-ANN JAYKUS
Keyword(s):  
Stainless Steel ◽  
Salmonella Typhimurium ◽  
Sampling Period ◽  
Stainless Steel Surface ◽  
Inoculum Level ◽  
Drying Time ◽  
Initial Inoculum ◽  
Significant Difference ◽  
Serovar Typhimurium ◽  
Handling Practices

The degree of transfer of Campylobacter jejuni and Salmonella enterica serovar Typhimurium was evaluated from a stainless steel contact surface to a ready-to-eat food (lettuce). Stainless steel coupons (25 cm2) were inoculated with a 20-μl drop of either C. jejuni or Salmonella Typhimurium to provide an inoculum level of ~106 CFU/28 mm2. Wet and dry lettuce (Lactuca sativa var. longifolia) pieces (9 cm2) were placed onto the inoculated stainless steel surface for 10 s after the designated inoculum drying time (0 to 80 min for C. jejuni; 0 to 120 min for Salmonella Typhimurium), which was followed by the recovery and enumeration of transferred pathogens (lettuce) and residual surface pathogens (stainless steel coupons). For transfers of Salmonella Typhimurium to dry lettuce, there was an increase from 36 to 66% in the percent transfer of the initial inoculum load during the first 60 min of sampling and then a precipitous drop from 66 to 6% in percent transfer. The transfer of Salmonella Typhimurium to wet lettuce ranged from 23 to 31%, with no statistically significant difference between recoveries over the entire 120-min sampling period. For C. jejuni, the mean percent transfer ranged from 16 to 38% for dry lettuce and from 15 to 27% for wet lettuce during the 80-min sampling period. The results of this study indicate that relatively high numbers of bacteria may be transferred to a food even 1 to 2 h after surface contamination. These findings can be used to support future projects aimed at estimating the degree of risk associated with poor handling practices of ready-to-eat foods.

Biosurfactant production and its effects on solubilization activity of phenanthrene: a longitudinal study

2016 ◽  
Vol 74 (3) ◽  
pp. 580-585
Author(s):  
Masoumeh Golshan ◽  
Maryam Dastoorpour ◽  
Roshanak Rezaei Kalantary
Keyword(s):  
Time Course ◽  
Inoculum Size ◽  
Biosurfactant Production ◽  
Practical Application ◽  
Time Intervals ◽  
Initial Inoculum ◽  
Bacterial Inoculum ◽  
Polycyclic Aromatic ◽  
The Mean ◽  
Time Course Study

Pseudomonas facilis and Pseudomonasspp., isolated on the basis of its ability to grow on polycyclic aromatic hydrocarbon, was assayed for biosurfactant production (BP) potentials by measuring the surface tension (ST) of the culture supernatant at different time intervals. The strains in three levels of initial inoculum size (OD600 nm = 0.5, 1, 1.5) were added to medium to determine if bacterial inoculum size affects solubilization of phenanthrene (PHE).The result showed that although the two strains reduced the mean ST to less than 34.12 mN m−1 at the end of day 6, mean solubilization activity of PHE reached 77.05 mg L−1 on the sixth day. There was a significant increase in BP over time (P = 0.008); reaching its peak, 157.84 mg L−1, at the end of the sixth day. Mean solubilization activity of PHE was not significantly different for the two strains (P = 0.216). The time-course study revealed that the ST reduction and BP potential was enhanced as inoculation size increased, leading to higher PHE solubility during the incubation time. However, the trend of increase in PHE solubility was not totally in the same way to cell growth and BP. It may be suggested that more bacterial density needs to be inoculated for practical application of effective bioremediation.

Effect of Oxygen Stress on Growth and Survival of Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes under Different Storage Conditions

2015 ◽  
Vol 78 (4) ◽  
pp. 691-697 ◽  
Author(s):  
HAMZAH AL-QADIRI ◽  
SHYAM S. SABLANI ◽  
MAHMOUDREZA OVISSIPOUR ◽  
NIVIN AL-ALAMI ◽  
BYJU GOVINDAN ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Campylobacter Jejuni ◽  
Clostridium Perfringens ◽  
Foodborne Pathogens ◽  
Storage Conditions ◽  
Growth And Survival ◽  
Anoxic Conditions ◽  
Initial Inoculum ◽  
Log Reduction ◽  
Packaged Food

This study investigated the growth and survival of three foodborne pathogens (Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes) in beef (7% fat) and nutrient broth under different oxygen levels. Samples were tested under anoxic (<0.5%), microoxic (6 to 8%), and oxic (20%) conditions during storage at 7°C for 14 days and at 22°C for 5 days. Two initial inoculum concentrations were used (1 and 2 log CFU per g of beef or per ml of broth). The results show that C. perfringens could grow in beef at 22°C, with an increase of approximately 5 log under anoxic conditions and a 1-log increase under microoxic conditions. However, C. perfringens could not survive in beef held at 7°C under microoxic and oxic storage conditions after 14 days. In an anoxic environment, C. perfringens survived in beef samples held at 7°C, with a 1-log reduction. A cell decline was observed at 2 log under these conditions, with no surviving cells at the 1-log level. However, the results show that C. jejuni under microoxic conditions survived with declining cell numbers. Significant increases in L. monocytogenes (5 to 7 log) were observed in beef held at 22°C for 5 days, with the lowest levels recovered under anoxic conditions. L. monocytogenes in refrigerated storage increased by a factor of 2 to 4 log. It showed the greatest growth under oxic conditions, with significant growth under anoxic conditions. These findings can be used to enhance food safety in vacuum-packed and modified atmosphere–packaged food products.

Rapid Detection of Campylobacter jejuni in Poultry Products Using QD-FRET Based Fluoroimmunoassay

2015 ◽  
Vol 14 (10) ◽  
pp. 548-553 ◽  
Author(s):  
Hong Wang ◽  
Michael Slavik ◽  
Yanbin Li ◽  
Andrew Wang
Keyword(s):  
Campylobacter Jejuni ◽  
Rapid Detection ◽  
Poultry Products

Inhibition of Listeria monocytogenes and Escherichia coli O157:H7 on Beef by Application of Organic Acids†

1996 ◽  
Vol 59 (4) ◽  
pp. 370-373 ◽  
Author(s):  
R. K. PODOLAK ◽  
J. F. ZAYAS ◽  
C. L. KASTNER ◽  
D. Y. C. FUNG
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Fumaric Acid ◽  
Rank Order ◽  
Escherichia Coli O157 ◽  
Inoculum Level ◽  
Initial Inoculum ◽  
E Coli ◽  
Lean Beef ◽  
Lactic Acids

Lean beef surfaces were inoculated with Escherichia coli O157:H7 and Listeria monocytogenes and then sanitized with fumaric, acetic, or lactic acid alone and in combined solutions of those acids at 55°C for 5 s. The initial inoculum level was 8.62 log CFU/cm2 and 5.13 log CFU/cm2 for L. monocytogenes and E. coli O157:H7, respectively. Fumaric acid at a concentration of 1% was the most effective acid in reducing the populations of L. monocytogenes by up to 1 log unit and E. coli O157:H7 by up to 1.3 log units when compared with acetic or lactic acids. The rank order of acids tested against the growth of L. monocytogenes and E. coli O157:H7 was fumaric acid followed by lactic and acetic acids. Fumaric acid at concentrations of 1.0% and 1.5% was more effective than any of the combined solutions of acids.

Passage of Campylobacter jejuni and Campylobacter coli Subtypes through 0.45- and 0.65-Micrometer-Pore-Size Nitrocellulose Filters

2017 ◽  
Vol 80 (12) ◽  
pp. 2029-2032 ◽  
Author(s):  
Mark E. Berrang ◽  
Richard J. Meinersmann ◽  
Nelson A. Cox
Keyword(s):  
Pore Size ◽  
Campylobacter Jejuni ◽  
Soft Agar ◽  
Filter Method ◽  
Campylobacter Coli ◽  
Direct Plating ◽  
Complex Samples ◽  
Liquid Cultures ◽  
Cellular Density ◽  
The Mean

ABSTRACT Campylobacter can be difficult to recover from complex samples due to overgrowth by background bacteria. A 0.45- or 0.65-μm-pore-size filter overlaid on agar plates can be used as a means to separate Campylobacter from confounding non-Campylobacter cells, facilitating detection on solid plating media. It is unclear what percentage of cells in a Campylobacter suspension passes through a filter and results in visible colonies. The objective of this study was to compare the number of Campylobacter cells detected by the filter method with those detected by direct plating and determine if the filter method can be used to estimate cellular density of an unknown Campylobacter in suspension. Overnight liquid cultures of six subtypes of Campylobacter jejuni and six of Campylobacter coli, all originally detected in chicken samples, were used for this study. Motility of isolates was tested by using a stab into soft agar, incubating plates, and measuring colony size. Each subtype was applied to Campy-Cefex agar directly and through a 0.45- or 0.65-μm-pore-size filter. Filters were removed, plates were incubated, and colonies were counted; three replications were conducted. Mean recovery by direct plating was 8.3 log CFU/mL. Regardless of pore size, the overall mean number of Campylobacter detected by using the filter method was significantly less than that using direct plating (P < 0.05). The mean difference between direct plating and plating though a 0.65-μm-pore-size filter for motile Campylobacter was log 2.4 CFU/mL, with a 95% confidence interval of ±0.2 log CFU/mL.

scholarly journals Detection of Vibrio parahaemolyticus in Shellfish by Use of Multiplexed Real-Time PCR with TaqMan Fluorescent Probes

2006 ◽  
Vol 72 (3) ◽  
pp. 2031-2042 ◽  
Author(s):  
Linda N. Ward ◽  
Asim K. Bej
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Vibrio Parahaemolyticus ◽  
Detection Methods ◽  
Tissue Homogenate ◽  
Oyster Tissue ◽  
Reading Frame ◽  
Initial Inoculum ◽  
Hemolysin Gene ◽  
Pure Cultures

ABSTRACT We developed a multiplexed real-time PCR assay using four sets of gene-specific oligonucleotide primers and four TaqMan probes labeled with four different fluorophores in a single reaction for detection of total and pathogenic Vibrio parahaemolyticus, including the pandemic O3:K6 serotype in oysters. V. parahaemolyticus has been associated with outbreaks of food-borne gastroenteritis caused by the consumption of raw or undercooked seafood and therefore is a concern to the seafood industry and consumers. We selected specific primers and probes targeting the thermostable direct hemolysin gene (tdh) and tdh-related hemolysin gene (trh) that have been reported to be associated with pathogenesis in this organism. In addition, we targeted open reading frame 8 of phage f237 (ORF8), which is associated with a newly emerged virulent pandemic serotype of V. parahameolyticus O3:K6. Total V. parahaemolyticus was targeted using the thermolabile hemolysin gene (tlh). The sensitivity of the combined four-locus multiplexed TaqMan PCR was found to be 200 pg of purified genomic DNA and 104 CFU per ml for pure cultures. Detection of an initial inoculum of 1 CFU V. parahaemolyticus per g of oyster tissue homogenate was possible after overnight enrichment, which resulted in a concentration of 3.3 × 109 CFU per ml. Use of this method with natural oysters resulted in 17/33 samples that were positive for tlh and 4/33 samples that were positive for tdh. This assay specifically and sensitively detected total and pathogenic V. parahaemolyticus and is expected to provide a rapid and reliable alternative to conventional detection methods by reducing the analysis time and obviating the need for multiple assays.

Prevalence of Campylobacter jejuni on Turkey Wings at the Supermarket Level

1983 ◽  
Vol 46 (4) ◽  
pp. 292-294 ◽  
Author(s):  
HUSEIN M. RAYES ◽  
CONSTANTIN A. GENIGEORGIS ◽  
THOMAS B. FARVER
Keyword(s):  
Detection Limit ◽  
Campylobacter Jejuni ◽  
Time Of Arrival ◽  
The Mean

Campylobacter jejuni was found on 64.1% of 184 packaged fresh and on 55.6% of 81 frozen turkey wings purchased from local supermarkets over a 2-month period. The prevalence of the agent on the wings varied with sampling day. For fresh wings (12 samplings), it varied from 33.3% to 100% and for frozen wings (9 samplings), it varied from 17% to 100%. At a detection limit of 300 cells/wing, the mean number of C. jejuni on the positive fresh wings was 740 cells/wing (range 616 to 832) and on the frozen wings 890 cells/wing (range 661 to 1096). All fresh wings were purchased at the time of arrival at the supermarkets. Thirty packages of wings collected from the refrigerated shelves (2 to 4-d old) had no detectable C. jejuni.

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