Occurrence of Listeria monocytogenes in Raw Milk in Nebraska

1988 ◽  
Vol 51 (11) ◽  
pp. 840-841 ◽  
Author(s):  
MICHAEL B. LIEWEN ◽  
MARK W. PLAUTZ

Raw milk samples were obtained from bulk storage tanks of individual dairy farms in eastern Nebraska during February and July of 1986. One hundred different farms were tested during each period. One-tenth ml of each sample was plated directly onto McBride's Listeria Agar (MLA) and 30 ml was subjected to a four-week cold enrichment procedure. Suspect colonies from MLA were subjected to biochemical tests to confirm identity. Nine percent of all raw milk samples examined were determined to be positive for Listeria species after the cold enrichment procedure. Four percent contained L. monocytogenes and five percent contained L. innocua. Six percent and two percent of samples were found to contain L. monocytogenes in February and July respectively.

Author(s):  
C. S. Swetha ◽  
A. Jagadeesh Babu ◽  
K. Venkateswara Rao ◽  
S. Bharathy ◽  
R. A. Supriya ◽  
...  

This study was aimed to detect the prevalence of Pseudomonas aeruginosa in milk (n=125) samples which were collected from local vendors, private dairy farms in and around Tirupati. Pre-enrichment was done by taking 10ml of each sample and inoculated in 90 ml of Tryptone Soya broth and incubated at 370C for 24hrs. A loopful of culture was taken from broth and streaked on nutrient agar and Cetrimide agar plates and incubated at 370C for 24hrs which were further confirmed by biochemical tests. The nineteen positive samples for P.aeruginosa were further tested for antimicrobial susceptibility which has shown multi drug resistant ranging from four to twelve antimicrobials and Multiple Antibiotic Resistance (MAR) index ranges from 0.33 to 1.The isolates of P.aeruginosain the present study are highlyresistant to ampicillin, penicillin, and oxacillin (100%) and maximum sensitive to Vancomycin (5.3%) followed by Tetracycline (10.5%).


2002 ◽  
Vol 65 (1) ◽  
pp. 111-115 ◽  
Author(s):  
KWANG-SOO HA ◽  
SEON-JA PARK ◽  
SOOK-JAE SEO ◽  
JUNG-HYUN PARK ◽  
DUCK-HWA CHUNG

A total of 50 raw milk samples from Gyeongnam Province of Korea were examined for the incidence of Listeria monocytogenes between July 1998 and August 1998. L. monocytogenes isolated by biochemical test was confirmed by polymerase chain reaction (PCR) with two sets of primers designed from the invasion-associated protein (iap) gene. After standard PCR with external primers, the amplified DNA was confirmed by a second round of PCR with internal primers (nested PCR). Both the external and internal primers generated 468-bp and 287-bp products, respectively. Only one (G9 strain) of the three suspect samples that tested positive in biochemical tests for L. monocytogenes from 50 raw milk samples was also PCR positive. Following this procedure, PCR-positive G9 strain was confirmed by Southern blot using the 287-bp internal iap probe again. The detection limit of G9 strain by standard PCR assay was as few as 102 cells, equivalent to approximately 1 pg of L. monocytogenes DNA. These PCR assays may be useful for novel detection as well as rapid confirmation for L. monocytogenes from food samples and the field.


Author(s):  
Abongile Pekana ◽  
Ezekiel Green

Background: Staphylococcus aureus (S. aureus) occasionally threatens the life of the host as a persistent pathogen even though it is normal flora of humans and animals. We characterized drug resistance in S. aureus isolated from animal carcasses and milk samples from the abattoirs and dairy farms in the Eastern Cape Province. Methods: A total of 1000 meat swab samples and 200 raw milk samples were collected from selected abattoirs and dairy farms. S. aureus was isolated and positively identified using biochemical tests and confirmed by molecular methods. An antibiotic susceptibility test was performed on all isolates for 14 antibiotics and correspondent genes were detected. Results: Of the 1200 samples collected, 134 (11.2%) samples were positive for S. aureus. Resistance ranged from 71.6% for penicillin G to 39.2% for tetracycline. A resistance gene (blaZ) was detected in 13 (14.9%), while msrA was found in 31 (52.5%) of S. aureus isolates. Conclusions: The present result shows the potential dissemination of multidrug-resistant S. aureus strains in the dairy farms and abattoirs in the Eastern Cape. Therefore, this implies that the organism may rapidly spread through food and pose serious public health risk.


2017 ◽  
Vol 14 (2) ◽  
pp. 277-282 ◽  
Author(s):  
M. A. Islam ◽  
S. M. L. Kabir ◽  
M. T. Rahman

The study was intended for molecular detection of S. aureus isolated from raw cow’s milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying cultural properties on different selective media, biochemical tests, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found to be positive for S. aureus. S. aureus specific 16S rRNA gene was amplified from all isolates and identified as S. aureus. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the S. aureus isolates were resistant to amoxicillin (100%), erythromycin (73.33%) and tetracycline (73.33%) but sensitive to azithromycin (93.33%), ciprofloxacin (93.33%), gentamicin (100%), norfloxacin (86.67%) and streptomycin (86.67%).


1987 ◽  
Vol 50 (3) ◽  
pp. 188-192 ◽  
Author(s):  
J. LOVETT ◽  
D. W. FRANCIS ◽  
J. M. HUNT

To determine the incidence of Listeria monocytogenes in raw milk, an isolation method was evaluated and used to analyze milk from three areas of the United States. The incidence varied by area from 0% in California to 7% in Massachusetts, with an overall incidence of 4.2%. The highest incidence found in any area during a single sampling period was 12% in Massachusetts in March 1985. During that same sampling, the incidence for all Listeria species was 26%. Of the 27 L. monocytogenes strains isolated during the survey, 25 were pathogenic in adult mice. One of three Listeria ivanovii isolated was pathogenic. No other isolates demonstrated pathogenicity.


1993 ◽  
Vol 56 (3) ◽  
pp. 256-259 ◽  
Author(s):  
A. EL MARRAKCHI ◽  
A. HAMAMA ◽  
F. EL OTHMANI

Examination of 227 samples of milk and dairy products for Listeria monocytogenes showed that raw milk and some Moroccan traditionally made dairy products such as Iben and raib (fermented milks) and jben (fresh cheese) were contaminated with this pathogen. L. monocytogenes was the only Listeria species isolated except in one case in which it was associated with Listeria innocua. Pasteurized milk, fresh cream, and fresh and ripened cheeses (industrially made) were free from L. monocytogenes.


1990 ◽  
Vol 53 (8) ◽  
pp. 642-647 ◽  
Author(s):  
CURTT M. PERRY ◽  
CATHERINE W. DONNELLY

Silage samples representing approximately 10% of Vermont's dairy farms were tested for the presence of Listeria species. Listeria innocua was isolated from 15.3% of the silage samples, while Listeria monocytogenes was isolated from 2.9% of the examined samples. As silage pH increased, the incidence of Listeria increased concomitantly. Seventy-eight mesophilic lactic acid bacteria, indigenous to silage, were screened for specific and nonspecific antagonism against four L. monocytogenes indicator strains. Most of the silage isolates demonstrated nonspecific inhibition via lactic acid production against the L. monocytogenes indicator strains. None of the indigenous silage isolates tested in this survey demonstrated specific antagonism via production of bacteriocinogenic compounds.


2014 ◽  
Vol 44 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Shajuty Marjan ◽  
Kamal Kanta Das ◽  
Saurab Kishore Munshi ◽  
Rashed Noor

Purpose – Current study was carried to detect the presence of pathogenic bacteria including the drug-resistant ones from milk and milk products. The paper aims to discuss these issues. Design/methodology/approach – Twenty-six raw milk samples from ten different areas, 28 pasteurized milk samples from 12 different companies and 26 yogurt samples from ten different sources in Dhaka city were microbiologically analyzed through cultural and biochemical identification of the isolates. Drug resistance trait was also determined by the Kirby-Bauer method on Muller-Hinton agar. Findings – Out of 80 samples studied, 74 were found to harbor pathogens within a range of 102-104 cfu/ml, including Escherichia coli, Salmonella spp., Staphylococcus aureus, and Vibrio spp. The study of antibiogram revealed that most of the isolates were resistant against most of the commonly used antibiotics. Research limitations/implications – Employment of only cultural/ biochemical tests excluding the molecular detection of virulence and/or antibiotic resistance genes might stand as a shortfall of the study. Nevertheless, such basic approach of microbiology can make this type of study replicable in the resource poor settings in the other developing countries. Practical implications – Routine detection of drug-resistant bacteria can further unveil the complications in chemotherapy during the endemic food borne diseases. Social implications – The study outcome/knowledge would aid to a better public health management especially in the developing countries. Originality/value – The presence of drug-resistant pathogenic bacteria in most of the tested milk samples poses a great public health threat, especially to the children. Therefore, the study revealed the necessity of maintaining proper hygienic practice and care in handling and processing of milk and milk products.


1982 ◽  
Vol 45 (13) ◽  
pp. 1212-1213 ◽  
Author(s):  
J. OOSTEROM ◽  
G. B. ENGELS ◽  
R. PETERS ◽  
R. POT

A survey was done on the occurrence of Campylobacter jejuni in slaughtered cattle and raw milk from dairy farms in The Netherlands, In the first part of the survey, in which direct plating techniques were used, no C. jejuni was detected in any of 200 samples of caecal contents of cattle or in 200 samples of raw milk. A second series of investigations was done using a new enrichment procedure. This time C. jejuni was isolated from 11 of 200 caecal contents, but from none of 200 samples of milk. Further experiments showed that Campylobacter can survive in milk at 4°C for weeks, whether the milk was shaken with air (as occurs during the milking process) or not. Our investigations indicate that C. jejuni was not excreted with the milk. It can be concluded that cattle in The Netherlands do not play an important role in the epidemiology of C. jejuni.


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