scholarly journals Isolation, identification and virulence determinants of Streptococcus agalactiae from bovine subclinical mastitis in Egypt

2021 ◽  
Vol 15 (08) ◽  
pp. 1133-1138
Author(s):  
Khaled Abd EL-Hamid Abd El-Razik ◽  
Amany A Arafa ◽  
Ehab A Fouad ◽  
Abdelgayed M Younes ◽  
Abdulaziz M Almuzaini ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Streptococcus Agalactiae ◽  
Virulence Genes ◽  
Dairy Farms ◽  
Subclinical Mastitis ◽  
Small Scale ◽  
Virulence Determinants ◽  
Genetic Determinants ◽  
Milk Samples ◽  
Small Scale Dairy

Introduction: This study aimed to investigate the prevalence of contagious mastitis caused by Streptococcus agalctiae (S. agalactiae) in cattle from households and small-scale dairy farms in Egypt. Molecular characterization of S.agalactiae isolates was described including the genetic determinants of virulence to assess the genetic variation in isolated strains of S. agalactiae. Methodology: Three hundred and sixty milk samples were collected from 90 apparently healthy dairy cows randomly selected from household and small-scale dairy farms were examined by Somatic Cell Count (SCC) as an indicator for subclinical mastitis. S.agalactiae isolates were bacteriologically and molecularly identified followed by identification of virulence genes using PCR. Results: A total of 172 milk samples (47.77%) were positive with SCC > 200×103/ml. Bacteriological examination of the positive SCC milk samples revealed that 28 (16.28%) of the isolates were S.agalactiae. Molecular examination using PCR confirmed only 22 isolates of S. agalactiae (12.8%). Moreover, we used the pattern of virulence genes to address the genetic variation of S. agalactiae strains isolated from cases of contagious mastitis in cattle in Egypt. Virulence genes hylB, cylE, iagA, and bac were determined in 100%, 68.2%, 13.6% and 100% of isolates respectively. Conclusions: The use of molecular methods for the identification of the causative agent in mastitis confirmed that, in Egypt, Streptococcus agalactiae is considered as one of the predominant infectious agents among contagious mastitis causing pathogens. The pattern of virulence genes presented the genetic diversity of highly virulent S. agalactiae strains isolated from cases of contagious mastitis in cattle in Egypt.

scholarly journals Prevalence subclinical mastitis in small-scale dairy farms under grazing or in total confinement in the central highlands of Mexico

2020 ◽  
Vol 73 (01) ◽  
pp. 73-76
Author(s):  
Mariana Valle-Aguilar ◽  
Felipe Lopez-Gonzalez ◽  
Aurora Sainz-Ramirez ◽  
Carlos Manuel Arriaga-Jordan
Keyword(s):  
Dairy Farms ◽  
Subclinical Mastitis ◽  
Small Scale ◽  
Central Highlands ◽  
Small Scale Dairy

scholarly journals Prevalence of enterotoxins and other virulence genes of Staphylococcus aureus caused subclinical mastitis in dairy cows

2020 ◽  
Vol 13 (6) ◽  
pp. 1193-1198
Author(s):  
Rania M. Ewida ◽  
Amira A. T. Al-Hosary
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Toxic Shock Syndrome ◽  
Virulence Genes ◽  
Dairy Farms ◽  
Subclinical Mastitis ◽  
Enterotoxin Gene ◽  
Toxic Shock ◽  
Milk Samples ◽  
Dairy Animals

Background and Aim: Milk production is one of the main props for the national economy. One of the crucial problems in this industry is subclinical mastitis, which harms this industry that considered the backbone of the economy. It is an infectious and zoonotic disease; the infection can spread between dairy animals through milkers' hands, and milking machines, while the human infection occurs due to the consumption of apparently hygienic milk. Staphylococcus aureus is one of the main causative agents of clinical and subclinical mastitis. It is also considered one of the bacteria incriminated in food intoxication of humans due to its virulence factors as enterotoxins and toxic shock syndrome. The current study was designed to assess the prevalence of S. aureus and its enterotoxins, as well as, its other virulence factors in milk collected from cows that suffer from subclinical mastitis. Materials and Methods: Sixty cows were collected from different dairy farms located in Assiut Governorate, Egypt. These cows were subjected to the clinical examination of the udder and its lymph nodes before sampling. Milk samples were collected from clinically healthy udders. All the milk samples were examined by California mastitis test (CMT), polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) for confirmation subclinical mastitis, presence of S. aureus and its enterotoxins genes and other virulence factors in the examined milk samples. Results: The cows included in the current study had healthy udders. The sixty collected milk samples were tested by CMT. 48/60 (80.0%) were positive samples; from the 48 positive samples, 46 (95.83%) samples were confirmed positive by S. aureus 16s rRNA PCR assay. Multiplex PCRs confirmed the presence of staphylococcus enterotoxin gene C (sec) in one sample, staphylococcus enterotoxin gene D (sed) in 23 samples, while ELISA assay confirmed the presence of the same enterotoxin in only two samples. On the other hand, other groups of genes responsible for some other virulence factors of S. aureus like the extracellular thermostable nuclease (nuc) gene were found in 33 samples, while toxic shock syndrome (tsst) gene and methicillin restraint S. aureus (mecA) gene were not detected in this study. Conclusion: Subclinical mastitis is one of the hidden factors that adversely affect the health of both animals and humans. The milk is usually appeared good and may be consumed by humans especially children; however, it causes severe public health problems. In addition, the infected animals with this form of mastitis can spread the infection to other dairy animals and may be turned to a clinical case of contagious mastitis that may be ended by animal culling or death. S. aureus is one of the main causes of subclinical mastitis in cattle. In addition to extracellular thermostable nuclease (nuc) gene, staphylococcus enterotoxin gene C (sec) and staphylococcus enterotoxin gene D (sed) are the most common virulence genes confirmed in subclinical mastitis milk. These results highlighted the need to apply more hygienic measures in the dairy farms to avoid spreading the infection between animals to ensure the production of safe and healthy food to humans.

scholarly journals Understanding Antibiotic Usage on Small-Scale Dairy Farms in the Indian States of Assam and Haryana Using a Mixed-Methods Approach—Outcomes and Challenges

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1124
Author(s):  
Naresh Kumar ◽  
Garima Sharma ◽  
Eithne Leahy ◽  
Bibek R. Shome ◽  
Samiran Bandyopadhyay ◽  
...  
Keyword(s):  
Dairy Farms ◽  
Antibiotic Usage ◽  
Small Scale ◽  
Dairy Herds ◽  
Dairy Farmers ◽  
Indian States ◽  
Milk Samples ◽  
Potential Factor ◽  
Method Approach ◽  
Small Scale Dairy

The use and misuse of antibiotics in both humans and animals contributes to the global emergence of antimicrobial resistant (AMR) bacteria, a threat to public health and infection control. Currently, India is the world’s leading milk producer but antibiotic usage within the dairy sector is poorly regulated. Little data exists reflecting how antibiotics are used on dairy farms, especially on small-scale dairy farms in India. To address this lack of data, a study was carried out on 491 small-scale dairy farms in two Indian states, Assam and Haryana, using a mixed method approach where farmers were interviewed, farms inspected for the presence of antibiotics and milk samples taken to determine antibiotic usage. Usage of antibiotics on farms appeared low only 10% (95% CI 8–13%) of farmers surveyed confirmed using antibiotics in their dairy herds during the last 12 months. Of the farms surveyed, only 8% (6–11%) had milk samples positive for antibiotic residues, namely from the novobiocin, macrolides, and sulphonamide classes of antibiotics. Of the farmers surveyed, only 2% (0.8–3%) had heard of the term “withdrawal period” and 53% (40–65%) failed to describe the term “antibiotic”. While this study clearly highlights a lack of understanding of antibiotics among small-scale dairy farmers, a potential factor in the emergence of AMR bacteria, it also shows that antibiotic usage on these farms is low and that the possible role these farmers play in AMR emergence may be overestimated.

scholarly journals Microbial and Chemical Adulterants Assessment of Raw Cow Milk Collected from Dairy Farms of Hlabisa Villages, KwaZulu-Natal Province, South Africa

2019 ◽  
Author(s):  
N.H. Xulu ◽  
S. Jamal-Ally ◽  
K.D. Naidoo
Keyword(s):  
South Africa ◽  
Dairy Farms ◽  
The Body ◽  
Cow Milk ◽  
Small Scale ◽  
Total Bacterial Count ◽  
Dairy Farmers ◽  
Milk Samples ◽  
Kwazulu Natal ◽  
Small Scale Dairy

Background: Milk is one of the most nutritious foods providing a variety of proteins, fats, minerals, and vitamins needed to maintain, grow, and develop the body. The aim of this study was to assess microbial and chemical adulterants of raw cow milk collected from dairy farms of Hlabisa villages, KwaZulu-Natal Province, South Africa. Methods: A total of 68 raw cow milk samples were obtained from teats sampling points, milking buckets, and communal pooling buckets. The bacteriological analysis was conducted for the detection of various bacteria in milk samples. Biochemical tests were also done to detect some chemical adulterants in milk samples. Results: Total bacterial count of teats, milking buckets, and communal milk pooling buckets were 6.91, 6.06, and 6.06 log Colony Forming Unit (CFU)/ml, respectively. The most found chemical adulterant was urea detected in 23 out of 68 (33.8%) samples, followed by hydrogen peroxide showed in 22 out of 68 (32.3%) samples. However, none of the samples were contaminated with formalin, starch, and neutralizer. Conclusion: The present study revealed high microbial contamination of raw cow milk produced by rural small-scale dairy farmers of Hlabisa villages, KwaZulu-Natal Province, South Africa, indicating the lack of standard operating sanitation. It was also stated that raw milk samples contained various types of chemical adulterants that may lead to severe health problems. Good hygiene practices must be adopted by small-scale dairy farmers at every stage of their milk handling and processing.

Genetic diversity and population structure of Escherichia coli from neighboring small-scale dairy farms

2011 ◽  
Vol 49 (5) ◽  
pp. 693-702 ◽  
Author(s):  
Jesús Andrei Rosales-Castillo ◽  
Ma. Soledad Vázquez-Garcidueñas ◽  
Hugo Álvarez-Hernández ◽  
Omar Chassin-Noria ◽  
Alba Irene Varela-Murillo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Population Structure ◽  
Dairy Farms ◽  
Small Scale ◽  
Small Scale Dairy

scholarly journals Molecular characterization of virulence factors in Staphylococcus aureus isolated from bovine subclinical mastitis in central Ethiopia

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Desiye Tesfaye Tegegne ◽  
Gezahegne Mamo ◽  
Hika Waktole ◽  
Yohannes Equar Messele
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cows ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Animal Health ◽  
Subclinical Mastitis ◽  
Biochemical Tests ◽  
Milk Samples ◽  
Lactating Dairy Cows ◽  
Genomic Study

Abstract Purpose Staphylococcus aureus (S. aureus) is the most important pathogen involved in bovine mastitis in dairy production. S. aureus produces a spectrum of extracellular protein toxins and virulence factors which are thought to contribute to the pathogenicity of the organism. The aim of this work was to isolate and molecular characterize S. aureus associated with bovine subclinical mastitis in the central part of Ethiopia. Methods A total of 265 lactating dairy cows from various dairy farms in four different geographical locations were screened by the California mastitis test (CMT) for bovine subclinical mastitis. One hundred thirty CMT-positive milk samples were collected and transported to the laboratory. Different biochemical tests and polymerase chain reaction (PCR) were used for the identification of S. aureus isolates. Finally, PCR was performed for molecular detection of virulence genes. Results From a total of 265 lactating dairy cows screened, 49% (n = 130) were positive for bovine subclinical mastitis. One hundred thirty mastitic milk samples were subjected to bacterial culturing, and one hundred (76%) S. aureus isolates were identified based on phenotypic characters. Sixty-eight confirmed S. aureus isolates were obtained using PCR. The confirmed S. aureus isolates were tested for six virulence genes (tsst-1, hlb, eta, sea, clfA, and icaD) using PCR. Of the six virulence genes screened from all the isolates, only two (clfA and eta) were detected in the isolates. Out of 68 isolates, 25% and 22% were possessed the eta and clfA genes, respectively. Conclusion The presence of Staphylococcus aureus having virulence genes (eta and clfA) revealed that mastitis is a major concern nowadays affecting animal health, milk quality, and yield. Further genomic study of these isolates will provide broad new insights on virulence.

Performance of small-scale dairy farms in the highlands of central Mexico during the dry season under traditional feeding strategies

2014 ◽  
Vol 47 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Carlos Galdino Martínez-García ◽  
Adolfo Armando Rayas-Amor ◽  
Juan Pablo Anaya-Ortega ◽  
Francisco Ernesto Martínez-Castañeda ◽  
Angélica Espinoza-Ortega ◽  
...  
Keyword(s):  
Dairy Farms ◽  
Dry Season ◽  
Small Scale ◽  
Feeding Strategies ◽  
Central Mexico ◽  
Small Scale Dairy

scholarly journals Comparison of the population structure of Streptococcus uberis mastitis isolates from Austrian small-scale dairy farms and a Slovakian large-scale farm

2020 ◽  
Vol 103 (2) ◽  
pp. 1820-1830
Author(s):  
Regina Wald ◽  
Martina Baumgartner ◽  
Julia Gutschireiter ◽  
Benjamin Bazzanella ◽  
Katharina Lichtmannsperger ◽  
...  
Keyword(s):  
Population Structure ◽  
Large Scale ◽  
Dairy Farms ◽  
Small Scale ◽  
Streptococcus Uberis ◽  
Small Scale Dairy

scholarly journals Prevalence of coagulase-negative staphylococci in bovine mastitis in Zimbabwe

2002 ◽  
Vol 73 (2) ◽  
Author(s):  
T. Kudinha ◽  
C. Simango
Keyword(s):  
Somatic Cell ◽  
Enteric Bacteria ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Bacillus Species ◽  
Small Scale ◽  
Coagulase Negative Staphylococci ◽  
Somatic Cell Counts ◽  
Milk Samples ◽  
Cell Counts

This study was carried out to determine the prevalence of coagulase-negative staphylococci in clinical and subclinical mastitis in commercial and small-scale farms in Zimbabwe. Thirty five quarter milk samples from clinical mastitis cases and 371 quarter milk samples from cows with subclinical mastitis were cultured for bacterial pathogens. The most frequent pathogens isolated in clinical mastitis were the enteric bacteria (31.4 %), followed by coagulase negative staphylococci (22.9 %) and then Staphylococcus aureus (17.1 %), whereas in subclinical mastitis S. aureus (34.2 %) and coagulase-negative staphylococci were (33.2 %) the most common. Bacillus species were only isolated in milk samples from subclinical mastitis. Coagulase-negative staphylococci were observed in mixed infections with other bacteria in only 2.2 % of the 406 milk samples from clinical and subclinical mastitis where they were isolated together with Bacillus species in 6 of the 9 mixed infection cases. About 95 % of the milk samples from which 131 coagulase-negative staphylococci were isolated had correspondingly high somatic cell counts. The coagulase-negative staphylococci isolated most frequently were S. chromogenes (7.9 %), S. epidermidis (7.4 %) and S. hominis (5.9 %). They were all associated with high somatic cell counts. All the coagulase-negative staphylococci isolates were susceptible to cloxacillin and erythromycin, and more than 90 %of the isolates were susceptible to neomycin, penicillin and streptomycin. The highest resistance was to tetracycline (17.6 %), followed by lincomycin (13.7 %). About 8 % of the isolates were resistant to both penicillin and streptomycin.

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