scholarly journals Characterization of Virulence Factors in Enterotoxin-Producing Staphylococcus Aureus From Bulk Tank Milk

2021 ◽  
Author(s):  
Hye-Ri Jung ◽  
Young Ju Lee
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Bulk Tank Milk ◽  
Genetic Characteristics ◽  
Enterotoxin Genes ◽  
High Prevalence ◽  
Bulk Tank

Abstract Background: Staphylococcus aureus, a persistent and chronic mastitis-causing pathogen, produces various virulence factors, including enterotoxins. This study analyzed the genetic characteristics of bovine mastitis-related virulence factors to evaluate potential pathogenesis in S. aureus isolated from bulk tank milk.Results: Among 93 S. aureus isolates from 396 dairy farms in six factories operated by three dairy companies in Korea, 40 (43.0%) isolates carried at least one or more enterotoxin genes and there were significant differences between factories within the same company (p < 0.05). Moreover, S. aureus carrying enterotoxin genes showed a higher prevalence in all virulence genes tested in this study except for pvl and lukM, which were not detected in any isolate, than the isolates without enterotoxin genes. In particular, the prevalence of six genes (hla, hlb, lukED, fnbA, clfA, and clfB) was significantly higher in S. aureus carrying enterotoxin genes than isolates without enterotoxin genes (p < 0.05). The most common multilocus sequence type (ST) of 40 enterotoxin-producing isolates was ST188, and all isolates of ST188 harbored the see gene. However, none of the isolates of ST1 and ST72 carried the see gene, and all isolates of ST1 carried the seh gene.Conclusions: Although S. aureus isolated from bulk tank milk, not from mastitis, had a high prevalence of enterotoxins and virulence factors simultaneously, posing a public health threat. Moreover, high enterotoxins in bulk tank milk may be reflected by poor hygiene; therefore, it is important to develop strong monitoring and sanitation programs to ensure that dairy factories produce hygienic milk.

scholarly journals Occurrence of enterotoxin genes and macrorestriction analysis of Staphylococcus aureus isolated from bovine mastitis and bulk-tank milk samples in Italy. An epidemiological study

2004 ◽  
Vol 3 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Andrea Serraino ◽  
Leonardo Alberghini ◽  
Maria Cristina Fontana ◽  
Cosima Annemüller ◽  
Christoph Lämmler ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Epidemiological Study ◽  
Bovine Mastitis ◽  
Bulk Tank Milk ◽  
Milk Samples ◽  
Enterotoxin Genes ◽  
Bulk Tank

scholarly journals Whole-Genome Epidemiology and Characterization of Methicillin-Susceptible Staphylococcus aureus ST398 From Retail Pork and Bulk Tank Milk in Shandong, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaonan Zhao ◽  
Ming Hu ◽  
Cui Zhao ◽  
Qing Zhang ◽  
Lulu Li ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Protein A ◽  
Whole Genome ◽  
Staphylococcal Protein A ◽  
Sequencing Analysis ◽  
Bulk Tank Milk ◽  
Predominant Type ◽  
Bulk Tank ◽  
The One

Staphylococcus aureus (S. aureus) is now regarded as a zoonotic agent. Methicillin-susceptible S. aureus (MSSA) ST398 is a livestock-associated bacterium that is most prevalent in China, but there are currently no data available for Shandong. Therefore, the aim of this study was to investigate the epidemiology and characterization of MSSA ST398 from retail pork and bulk tank milk (BTM) in Shandong. A total of 67 S. aureus isolates were collected from retail pork between November 2017 and June 2018. Among the isolates, high antimicrobial resistance rates were observed for penicillin (97.0%), and 92.5% of the isolates were multi-drug resistant (MDR). Eight sequence types (STs) were identified in the retail pork isolates, and the predominant type was ST15 (n=26), which was followed by ST398 (n=14). Staphylococcal protein A gene (spa) typing identified spa types t034 and t1255 in MSSA ST398 from retail pork. Using whole-genome sequencing analysis, we described the phylogeny of 29 MSSA ST398 isolates that were obtained from retail pork (n=14) and BTM (n=15). The phylogenetic tree showed that the MSSA ST398 isolates from different sources had the same lineage. Among the 29 MSSA ST398 isolates, five resistance genes were detected, and all isolates carried DHA-1. Fifteen toxin genes were detected, and all isolates carried eta, hla, and hlb. In conclusion, this study found that a high risk for MSSA ST398 was present in retail pork and BTM. These findings have major implications for how investigations of MSSA ST398 outbreaks should be conducted in the One-Health context.

scholarly journals Short communication: Characterization of Staphylococcus aureus from bulk tank milk of dairy cattle in Lombardy (northern Italy)

2020 ◽  
Vol 103 (3) ◽  
pp. 2685-2692
Author(s):  
A. Gazzola ◽  
A.M. Maisano ◽  
V. Bianchini ◽  
F. Vezzoli ◽  
A. Romanò ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cattle ◽  
Short Communication ◽  
Northern Italy ◽  
Bulk Tank Milk ◽  
Bulk Tank

Dissemination and Characteristics of High-Level Erythromycin-Resistant Enterococcus Faecalis From Bulk Tank Milk of Dairy Companies in Korea

2021 ◽  
Author(s):  
Yu Jin Lee ◽  
Koeun Kim ◽  
Young Ju Lee
Keyword(s):  
Enterococcus Faecalis ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Bovine Mastitis ◽  
Bulk Tank Milk ◽  
Significant Difference ◽  
Bulk Tank ◽  
Environmental Pathogens ◽  
High Level ◽  
Genotypic Characteristics

Abstract Background: Enterococci are environmental pathogens that can cause bovine mastitis and macrolides are widely used for the treatment of bovine mastitis caused by staphylococci and streptococci/enterococci. The aim of this study was performed to compare the phenotypic and genotypic characteristics of high-level erythromycin-resistant (HLER) Enterococcus faecalis (E. faecalis) collected from bulk tank milk of four dairy companies (A, B, C, and D) in Korea. Results: Although isolates from company D showed the highest prevalence of E. faecalis, the prevalence of HLER E. faecalis in company A (73.1%) and C (57.0%) was significantly higher than company D (33.9%) (P < 0.05). A total of 149 HLER E. faecalis isolates showed high rates of resistance to tetracycline (93.3%), followed by doxycycline (70.0%), and chloramphenicol (48.3%). In the distribution of macrolides resistance genes, 147 (98.7%) isolates carried ermB gene alone, and two isolates carried both ermA and ermB genes. No isolates carried ermC, msrA, msrC, or mef genes. In the distribution of other resistance genes, 72 (48.3%) and 60 (40.3%) isolates carried both tetM and tetL genes, and tetM gene alone, respectively, and 38 (25.5%) isolates carried optrA gene. For aminoglycosides resistance genes, the prevalence of both aac(6′)Ie-aph(2″)-la and ant(6′)-Ia genes (43.0%) was the highest. Moreover, 104 (70.0%) isolates harbored Int-Tn gene carrying the Tn916/1545-like transposon. Although the distribution of ermB gene showed no significant difference between the dairy companies, the prevalence of other resistance genes and transposons showed a significant difference between the dairy companies (P < 0.05). Virulence genes, such as ace (99.3%), cad1 and efaA (each 98.7%), and gelE (83.9%), were also highly conserved in the 149 HLER E. faecalis isolates. Conclusions: Our results indicated that HLER E. faecalis isolates from bulk tank milk showed significant differences in phenotypic and genotypic characteristics between the dairy companies. In addition, the prevalence of resistance genes and virulence factors was also high in HLER E. faecalis isolates.

scholarly journals Characteristics of High-Level Aminoglycoside-Resistant Enterococcus faecalis Isolated from Bulk Tank Milk in Korea

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1724
Author(s):  
Hyo Jung Kang ◽  
Sunghyun Yoon ◽  
Koeun Kim ◽  
Young Ju Lee
Keyword(s):  
Antimicrobial Resistance ◽  
Enterococcus Faecalis ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Management Program ◽  
Bulk Tank Milk ◽  
Antimicrobial Resistance Genes ◽  
Bulk Tank ◽  
High Level

Enterococci, which are considered environmental mastitis-causing pathogens, have easily acquired aminoglycoside-resistant genes that encode various aminoglycoside-modifying enzymes (AME). Therefore, this study was conducted to compare the distribution of high-level aminoglycoside-resistant (HLAR) and multidrug-resistant (MDR) Enterococcus faecalis (E. faecalis) bacteria isolated from bulk tank milk in four dairy companies in Korea. Moreover, it analyzed the characteristics of their antimicrobial resistance genes and virulence factors. Among the 301 E. faecalis bacteria studied, 185 (61.5%) showed HLAR with no significant differences among the dairy companies. Furthermore, 129 (69.7%) of the 185 HLAR E. faecalis showed MDR without significant differences among companies. In contrast, HLAR E. faecalis from companies A, B, and C were significantly higher in resistance to the four classes than those in company D, which had the highest MDR ability against the three antimicrobial classes (p < 0.05). In addition, in the distribution of AME genes, 72 (38.9%) and 36 (19.5%) of the isolates carried both aac(6′)Ie-aph(2″)-la and ant(6)-Ia genes, and the ant (6)-Ia gene alone, respectively, with significant differences among the companies (p < 0.05). In the distribution of virulence genes, the ace (99.5%), efa A (98.9%), and cad 1 (98.4%) genes were significantly prevalent (p < 0.05). Thus, our results support that an advanced management program by companies is required to minimize the dissemination of antimicrobial resistance and virulence factors.

scholarly journals Characterisation of Staphylococcus aureus isolated from rabbits in Fujian, China

2019 ◽  
Vol 147 ◽  
Author(s):  
J. Wang ◽  
L. Sang ◽  
S. Sun ◽  
Y. Chen ◽  
D. Chen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Virulence Genes ◽  
Susceptibility Test ◽  
Antimicrobial Susceptibility Test ◽  
Fujian Province ◽  
Genetic Characteristics ◽  
Resistance Rates ◽  
Sequence Types

Abstract Staphylococcus aureus has been recognised as one of the important zoonotic pathogens. However, knowledge about the epidemiology and genetic characteristics of S. aureus in rabbits was limited. The aim of this study was to determine the characteristics of 281 S. aureus isolated from dead rabbits of nine rabbit farms in Fujian Province, China. All the isolates were characterised by multi-locus sequencing typing, detection of virulence factors and antimicrobial susceptibility test. The results showed that the 281 isolates were grouped into two sequence types, ST121 (13.52%, 38/281) and ST398 (86.48%, 243/281). Surprisingly, the ST121 strains were only recovered from the lung samples from one of the nine rabbit farms studied. In the 281 isolates, the virulence genes of nuc, hla, hlb, clfA, clfB and fnbpA were positive, whereas the sea, seb, tsst, eta and etb genes were negative. Notably, the 38 ST121 isolates carried the pvl gene. All the 281 isolates were methicillin-susceptible S. aureus, and the isolates were susceptible to most of the used antibiotics, except for streptomycin, kanamycin, azithromycin and penicillin, and the resistance rates of which were 23.84%, 19.57%, 16.01% and 11.03%, respectively. This study first described the epidemiology and characteristics of S. aureus in rabbits in Fujian Province, which will help in tracking the evolution of epidemic strains and preventing the rabbit–human transmission events.

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