LISTERIA MONOCYTOGENES IN COW’S MILK PRODUCED BY FAMILY-OWNED DAIRY FARMS

2020 ◽  
Vol 27 ◽  
pp. 1-10
Author(s):  
Benedito Menozzi
Keyword(s):  
Listeria Monocytogenes ◽  
Animal Health ◽  
Dairy Farms ◽  
Microbiological Analysis ◽  
Chain Reaction ◽  
Psychrotrophic Bacteria ◽  
Milk Samples ◽  
Negative Results ◽  
Preservation Method ◽  
Polymerase Chain

Refrigeration is an important milk preservation method. However, milk quality may deteriorate if the product is refrigerated for long periods, mainly due to the growth of psychrotrophic bacteria. This group of microorganisms includes pathogenic genera, most notably Listeria monocytogenes. The detection of this bacterium in food is important, given its pathogenic effects on human and animal health and also its economic relevance. This study focused on detecting the presence of L. monocytogenes in milk samples collected at small family-owned dairy farms. Samples were cultivated on PALCAM and ALOA agars for microbiological analysis and a molecular analysis by polymerase chain reaction was performed for the detection of L. monocytogenes. Despite the negative results obtained in both these analyses, further studies are recommended to confirm or refute the negligible effect of L. monocytogenes on small dairy farms.

Detection of clinical bovine mastitis caused by Mycoplasma bovis in Brazil

2020 ◽  
Vol 87 (3) ◽  
pp. 306-308
Author(s):  
Nathália Brancato Junqueira ◽  
Anelise Salina ◽  
Gabriela Capriogli Oliveira ◽  
Elena Mettifogo ◽  
Sâmea Fernandes Joaquim ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Bovine Mastitis ◽  
Dairy Farms ◽  
Clinical Mastitis ◽  
Dairy Herds ◽  
Mycoplasma Bovis ◽  
Chain Reaction ◽  
Research Communication ◽  
Milk Samples ◽  
Polymerase Chain

AbstractThe work reported in this research communication investigated the occurrence of Mycoplasma bovis (M. bovis) in milk samples from cows with clinical mastitis on dairy farms from seven Brazilian states. We hypothesized that M. bovis was present in bovine clinical mastitis milk in Brazil. A total of 561 milk samples were cultured on Hayflick agar and incubated in a microaerophilic atmosphere at 5% CO2. Polymerase chain reaction (PCR) was performed for the detection of Mycoplasma spp. and Mycoplasma bovis in milk samples. Mycoplasma spp. were isolated in 2% of the milk samples, and Mycoplasma bovis was verified in 3% of the milk samples by PCR. The results showed that Mycoplasma bovis is involved in clinical mastitis in Brazilian dairy herds. We emphasize the need for further studies to investigate the infection by this agent in clinical mastitis cases, particularly in Brazil, due to the lack of knowledge about its prevalence.

scholarly journals Quantification of psychrotrophic bacteria and molecular identification of Pseudomonas fluorescens in refrigerated raw milk

2019 ◽  
Vol 86 ◽  
Author(s):  
Camila Lampugnani ◽  
Mykaella Zanatta Was ◽  
Maike Taís Maziero Montanhini ◽  
Luis Augusto Nero ◽  
Luciano dos Santos Bersot
Keyword(s):  
Pseudomonas Fluorescens ◽  
Proteolytic Activity ◽  
Molecular Identification ◽  
Raw Milk ◽  
Chain Reaction ◽  
Psychrotrophic Bacteria ◽  
Milk Samples ◽  
16S Gene ◽  
Polymerase Chain ◽  
Proteolytic Capacity

ABSTRACT In this study, we investigated the contamination of refrigerated raw milk produced in the western region of Paraná, southern Brazil, with psychrotrophic microorganisms, aiming to assay the proteolytic activity of the isolates and to identify Pseudomonas fluorescens, the main proteolytic species associated with the spoilage of milk products. Raw milk samples from 50 dairy farms were submitted to the counting of psychrotrophic microorganisms, being the microbiota characterized by its mesophilic behavior and proteolytic capacity, besides molecular identification of P. fluorescens. Of the samples evaluated, 94% had psychrotrophic counts ranging from 3 to 7.1 log CFU mL-1, and 48.5% of these showed mesophilic behavior. Of the isolates, 48.0% had proteolytic activity in at least one evaluated temperature (21 and 30°C), and 39.3% had proteolytic activity in both temperatures. Among the 61 isolates submitted to molecular identification by polymerase chain reaction (PCR), 86.8% contained the expression of the 16S gene characteristic for P. fluorescens. In this study, we demonstrated that P. fluorescens is the most prevalent psychrotrophic bacteria species in raw refrigerated milk and their proteolytic ability poses high risks to the dairy industry.

scholarly journals Detection of coagulase gene in Staphylococcus aureus from several dairy farms in East Java, Indonesia, by polymerase chain reaction

2019 ◽  
Vol 12 (1) ◽  
pp. 68-71 ◽  
Author(s):  
Mustofa Helmi Effendi ◽  
Mirza Atikah Madarina Hisyam ◽  
Poedji Hastutiek ◽  
Wiwiek Tyasningsih
Keyword(s):  
Staphylococcus Aureus ◽  
Polymerase Chain Reaction ◽  
Dairy Farms ◽  
Raw Milk ◽  
Chain Reaction ◽  
Milk Samples ◽  
Epidemiological Tool ◽  
Gene Polymerase Chain Reaction ◽  
Polymerase Chain ◽  
Coa Gene

Aim: This study was conducted to study the coagulase (coa) gene-based genetic diversity of Staphylococcus aureus, isolated from different samples of cattle from three different regions in East Java Province, Indonesia. Materials and Methods: A total of 160 raw milk samples collected in East Java Province, Indonesia, were screened for the presence of S. aureus. The presumptive isolates were confirmed by coa test. The confirmed S. aureus isolates were subjected to coa gene polymerase chain reaction. Results: Of 160 different samples, 20 (12.5%) isolates of S. aureus were confirmed by positive coa test. Of 20 S. aureus isolates, 19 (95%) isolates carried coa gene. Six different genotypes of coa gene, i.e., 440 bp, 510 bp, 547 bp, 680 bp, 740 bp, and 820 bp were obtained. One coa genotypes, 510 bp (10 isolates) were observed in polymorphism to be more prevalent than the others, and the genotype was present in at least one isolates from every region. Conclusion: It can be concluded that coa gene is easily epidemiological tool for detection of variation strain from S. aureus.

Incidence and Polymerase Chain Reaction Assay of Listeria monocytogenes from Raw Milk in Gyeongnam Province of Korea

2002 ◽  
Vol 65 (1) ◽  
pp. 111-115 ◽  
Author(s):  
KWANG-SOO HA ◽  
SEON-JA PARK ◽  
SOOK-JAE SEO ◽  
JUNG-HYUN PARK ◽  
DUCK-HWA CHUNG
Keyword(s):  
Polymerase Chain Reaction ◽  
Listeria Monocytogenes ◽  
Raw Milk ◽  
Food Samples ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Biochemical Tests ◽  
Milk Samples ◽  
Polymerase Chain ◽  
Pcr Assays

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.

scholarly journals PCR Assay With Host Specific Internal Control for Staphylococcus Aureus From Bovine Milk Samples

2015 ◽  
Vol 38 (1) ◽  
pp. 97-100 ◽  
Author(s):  
Zafer Cantekin ◽  
Yasar Ergun ◽  
Hasan Solmaz ◽  
Gamze Özge Özmen ◽  
Melek Demir ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Polymerase Chain Reaction ◽  
False Negative ◽  
Bovine Milk ◽  
Chain Reaction ◽  
Specific Primers ◽  
Milk Samples ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Abstract Staphylococcus aureus is considered as one of the most important and common pathogens of bovine mastitis. Polymerase Chain Reaction is frequently proposed in the diagnosis of S. aureus directly from milk samples instead of classical culture. However, false-negative results may occur in the polymerase chain reaction analysis performed directly from clinical material. For the purpose of disclosing the false negative results, the use of internal amplification controls can be beneficial. Therefore, in this study a new polymerase chain reaction technique with host specific internal amplification control was developed by optimizing S. aureus-specific primers in combination with bovine specific primers. The effectiveness of the developed technique in this study was attempted in milk samples from bovine subclinical mastitis. This technique has the potential to detect S. aureus from bovine milk samples or dairy products.

scholarly journals Amplification of human beta-actin gene by the reverse transcriptase-polymerase chain reaction: implications for assessment of RNA from formalin-fixed, paraffin-embedded material.

1996 ◽  
Vol 44 (10) ◽  
pp. 1205-1207 ◽  
Author(s):  
A Dakhama ◽  
V Macek ◽  
J C Hogg ◽  
R G Hegele
Keyword(s):  
Polymerase Chain Reaction ◽  
Pcr Amplification ◽  
Housekeeping Gene ◽  
Chain Reaction ◽  
Viral Genomes ◽  
Negative Results ◽  
Beta Actin ◽  
Target Nucleic Acid ◽  
Formalin Fixed Paraffin Embedded ◽  
Polymerase Chain

The polymerase chain reaction (PCR) is a powerful method that allows enzymatic amplification of rate target nucleic acid sequences. It has been applied to the amplification of viral genomes from paraffin-embedded pathology specimens. However, interpretation of negative results requires amplification of a housekeeping gene such as beta-actin. In the present study we used specific oligonucleotide primers previously designed to amplify both the genomic DNA and the mRNA transcript from paraffin-embedded tissue. These products have predicted sizes of 250 BP and 154 BP, respectively, but our results showed that PCR amplification only (without reverse transcription) unexpectedly generated the 154-BP product. Further investigation of the nature of this product demonstrated that it originated from the amplification of DNA, not RNA. We conclude that the 154-BP product generated by these primers cannot be exclusively considered as beta-actin RNA product and should not be used to assess successful extraction of RNA, to ascertain its integrity, or to normalize for the total amount of RNA assayed by RT-PCR from paraffin-embedded tissue.

scholarly journals UTILITY OF ANTIGEN DETECTION TEST AND POLYMERASE CHAIN REACTION IN THE DIFFERENTIATION OF TUBERCULOUS AND NON-TUBERCULOUS MYCOBACTERIA

2017 ◽  
Vol 10 (6) ◽  
pp. 289
Author(s):  
Yogita Singh ◽  
Raji Vasanth ◽  
Shrikala Baliga ◽  
Dhanashree B
Keyword(s):  
Polymerase Chain Reaction ◽  
False Negative ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Chain Reaction ◽  
College Hospital ◽  
Medical College ◽  
Negative Results ◽  
Polymerase Chain ◽  
Mycobacterium Spp

Objectives: Cultivation and identification of mycobacteria to species level remains difficult and time-consuming. Hence, easy and rapid diagnostic methods are necessary for the differentiation of Mycobacterium tuberculosis (MTB) from non-tuberculous mycobacteria (NTM). The present study aims to detect and differentiate MTB from NTM isolated from clinical samples by immunochromatographic test (ICT) and polymerase chain reaction (PCR). Methods: Over a period of 1 year, clinical samples (n=496) received from suspected cases of TB, at the Department of Microbiology, Kasturba Medical College Hospital, Mangalore were cultured to isolate Mycobacterium spp. Identification of all the isolates was done by conventional biochemical technique, ICT, and PCR. Results: Among the 496 samples processed, 49 (9.87%) were acid-fast bacilli smear positive and 59 (11.89%) samples showed the growth of Mycobacterium spp. Among these, 10 were rapid growers, 49 were slow-growing mycobacteria, out of which 30 were MTB as identified by conventional biochemical reaction. Out of 59 Mycobacterial isolates subjected to ICT for the detection of MPT 64 antigen, only 28 were identified as MTB. However, all the 30 isolates were correctly identified as MTB by PCR. Conclusion: Hence, PCR is essential for rapid differentiation of non-tuberculous Mycobacterium from MTB. False negative results seen with immunochromatographic MPT 64 antigen assay could be due to mutations within the mpt64 gene. Further studies are necessary to characterize these PCR-positive and immunochromatographic assay negative MTB isolates.

scholarly journals Suitability of different tissue fixatives for subsequent PCR analysis of Cysticercus ovis

2012 ◽  
Vol 49 (2) ◽  
pp. 67-70 ◽  
Author(s):  
M. Kolesárová ◽  
R. Herich ◽  
M. Levkut ◽  
J. Čurlík ◽  
M. Levkut
Keyword(s):  
Retrospective Studies ◽  
Pcr Amplification ◽  
Pcr Analysis ◽  
Chain Reaction ◽  
Fresh Tissue ◽  
Carnoy’S Solution ◽  
Negative Results ◽  
Pcr Product ◽  
Polymerase Chain ◽  
Cysticercus Ovis

AbstractPCR amplification of specific DNA regions is a powerful tool for retrospective studies, but not all preservation or fixation methods render DNA that is suitable for subsequent amplification. Several factors affect sensitivity of polymerase chain reaction (PCR) amplification. There were reported the effects of commonly used fixation solutions — 10 % neutral buffered formalin, 20 % neutral buffered formalin and Carnoy’s solution and the efficiency of PCR amplification in fresh tissue and paraffin (or wax) embedded samples of Cysticercus ovis. DNA from samples was isolated and PCR product of 1300 bp was amplified. Results indicated that the samples fixed in Carnoy’s solution produced reliable amplification of desired fragments. The samples that were fixed in 10 % and 20 % neutral buffered formalin brought negative results.

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