{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T21:04:48Z","timestamp":1792875888642,"version":"4.5.0"},"reference-count":104,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2021,5,29]],"date-time":"2021-05-29T00:00:00Z","timestamp":1622246400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006261","name":"Taif University","doi-asserted-by":"publisher","award":["TURSP -2020\/111"],"award-info":[{"award-number":["TURSP -2020\/111"]}],"id":[{"id":"10.13039\/501100006261","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Mastitis is a significant disease affecting dairy cattle farms in Egypt. The current study aimed to investigate the prevalence and major bacterial pathogens causing subclinical mastitis (SCM) in three bovine dairy herds, with a history of SCM, at three Governorates in North Upper Egypt. The antimicrobial resistance profiles and specific virulence-associated genes causing bovine SCM were investigated. One thousand sixty-quarter milk samples (QMS) were collected aseptically from 270 apparently healthy cows in three farms and examined. The total prevalence of SCM was 46% and 44.8% based on California Mastitis Test (CMT) and Somatic Cell Count (SCC), respectively. Bacteriological examination of CMT positive quarters revealed that the prevalence of bacterial isolation in subclinically mastitic quarters was 90.4% (26 and 64.3% had single and mixed isolates, respectively). The most frequent bacterial isolates were E. coli (49.8%), Staphylococcus aureus (44.9%), streptococci (44.1%) and non-aureus staphylococci (NAS) (37.1%). Antimicrobial susceptibility testing of isolates revealed a high degree of resistance to the most commonly used antimicrobial compound in human and veterinary medicine. Implementation of PCR revealed the presence of mecA and blaZ genes in 60% and 46.7% of S. aureus isolates and in 26.7% and 53.3% of NAS, respectively. Meanwhile 73.3% of streptococci isolates harbored aph(3\u2019)-IIIa gene conferring resistance to aminoglycosides and cfb gene. All E. coli isolates harbored tetA gene conferring resistance to tetracycline and sul1 gene conferring resistance to sulfonamides. The fimH and tsh genes were found in 80% and 60%, respectively. A significant association between the phenotypes and genotypes of AMR in different bacteria was recorded. The presence of a high prevalence of SCM in dairy animals impacts milk production and milk quality. The coexistence of pathogenic bacteria in milk is alarming, threatens human health and has a public health significance. Herd health improvement interventions are required to protect human health and society.<\/jats:p>","DOI":"10.3390\/microorganisms9061175","type":"journal-article","created":{"date-parts":[[2021,5,31]],"date-time":"2021-05-31T01:51:37Z","timestamp":1622425897000},"page":"1175","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":52,"title":["Subclinical Mastitis in Selected Bovine Dairy Herds in North Upper Egypt: Assessment of Prevalence, Causative Bacterial Pathogens, Antimicrobial Resistance and Virulence-Associated Genes"],"prefix":"10.3390","volume":"9","author":[{"given":"Ahmed H.","family":"Abed","sequence":"first","affiliation":[{"name":"Bacteriology, Mycology and Immunology Department, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7219-580X","authenticated-orcid":false,"given":"Ahmed M. S.","family":"Menshawy","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed M. A.","family":"Zeinhom","sequence":"additional","affiliation":[{"name":"Food Hygiene and Control Department, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef 62511, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9269-5353","authenticated-orcid":false,"given":"Delower","family":"Hossain","sequence":"additional","affiliation":[{"name":"Department of Medicine and Public Health, Faculty of Animal Science and Veterinary Medicine, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka 1207, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1029-9571","authenticated-orcid":false,"given":"Eman","family":"Khalifa","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Faculty of Veterinary Medicine, Matrouh University, Matrouh 51511, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6259-1932","authenticated-orcid":false,"given":"Gamal","family":"Wareth","sequence":"additional","affiliation":[{"name":"Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07743 Jena, Germany"},{"name":"Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh 13736, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0467-9164","authenticated-orcid":false,"given":"Mohamed F.","family":"Awad","sequence":"additional","affiliation":[{"name":"Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kova\u010devi\u0107, Z., Radinovi\u0107, M., \u010cabarkapa, I., Kladar, N., and Bo\u017ein, B. (2021). Natural Agents against Bovine Mastitis Pathogens. Antibiotics, 10.","DOI":"10.3390\/antibiotics10020205"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Abebe, R., Hatiya, H., Abera, M., Megersa, B., and Asmare, K. (2016). Bovine mastitis: Prevalence, risk factors and isolation of Staphylococcus aureus in dairy herds at Hawassa milk shed, South Ethiopia. BMC Vet. Res., 12.","DOI":"10.1186\/s12917-016-0905-3"},{"key":"ref_3","first-page":"499","article-title":"Genotyping of \u03b2-lactams resistant staphylococci isolated from bovine subclinical mastitis","volume":"7","author":"Abed","year":"2018","journal-title":"Beni-Suef Univ. J. Basic Appl. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Brennecke, J., Falkenberg, U., Wente, N., and Kr\u00f6mker, V. (2021). Are severe mastitis cases in dairy cows associated with bacteremia?. Animals, 11.","DOI":"10.3390\/ani11020410"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1007\/s11250-014-0688-0","article-title":"Different screening tests and milk somatic cell count for the prevalence of subclinical bovine mastitis in Bangladesh","volume":"47","author":"Hoque","year":"2015","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_6","unstructured":"Constable, P.D., Hinchcliff, K.W., Done, S.H., and Gr\u00fcnberg, W. (2017). Veterinary Medicine-e-Book: A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs and Goats, Elsevier. [11th ed.]."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1007\/s11250-005-7049-y","article-title":"Reduced milk production in udder quarters with subclinical mastitis and associated economic losses in cross-bred dairy cows in Ethiopia","volume":"37","author":"Mungube","year":"2005","journal-title":"Trop. Anim. Health"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2416","DOI":"10.3168\/jds.2018-15135","article-title":"Antimicrobial resistance profiles of 5 common bovine mastitis pathogens in large Chinese dairy herds","volume":"102","author":"Cheng","year":"2019","journal-title":"J. Dairy Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.cvfa.2012.03.005","article-title":"Antimicrobial resistance of mastitis pathogens","volume":"28","author":"Oliver","year":"2012","journal-title":"Vet. Clin. North. Am. Food Anim. Pract."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1007\/s11250-021-02703-5","article-title":"Chronic incurable mastitis in sheep: Prevalence, identification of predisposing factors, and genotyping of fungal causative species using PCR-RFLP","volume":"53","author":"Mousa","year":"2021","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1193","DOI":"10.14202\/vetworld.2020.1193-1198","article-title":"Prevalence of enterotoxins and other virulence genes of Staphylococcus aureus caused subclinical mastitis in dairy cows","volume":"13","author":"Ewida","year":"2020","journal-title":"Vet. World"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"186","DOI":"10.5455\/javar.2020.g409","article-title":"Antimicrobial profile of multidrug-resistant Streptococcus spp. isolated from dairy cows with clinical mastitis","volume":"7","author":"Saed","year":"2020","journal-title":"J. Adv. Vet. Anim. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"337","DOI":"10.7883\/yoken.JJID.2018.538","article-title":"Serotypes, pathogenic potential and antimicrobial resistance of Escherichia coli isolated from subclinical bovine mastitis milk samples in Egypt","volume":"72","author":"Ombarak","year":"2019","journal-title":"Jpn. J. Infect. Dis."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2596","DOI":"10.14202\/vetworld.2020.2596-2607","article-title":"Epidemiology and antibiogram of common mastitis-causing bacteria in Beetal goats","volume":"13","author":"Jabbar","year":"2020","journal-title":"Vet. World"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Ahmed, W., Neubauer, H., Tomaso, H., El Hofy, F.I., Monecke, S., Abd El-Tawab, A.A., and Hotzel, H. (2021). Characterization of enterococci- and ESBL-Producing Escherichia coli isolated from milk of bovides with mastitis in Egypt. Pathogens, 10.","DOI":"10.3390\/pathogens10020097"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Algammal, A.M., Enany, M.E., El-Tarabili, R.M., Ghobashy, M.O.I., and Helmy, Y.A. (2020). Prevalence, antimicrobial resistance profiles, virulence and enterotoxin-determinant genes of MRSA isolated from subclinical bovine mastitis samples in Egypt. Pathogens, 9.","DOI":"10.3390\/pathogens9050362"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3855","DOI":"10.1007\/s11250-020-02424-1","article-title":"Microarray-based detection of resistance genes in coagulase-negative staphylococci isolated from cattle and buffalo with mastitis in Egypt","volume":"52","author":"Gwida","year":"2020","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"42791","DOI":"10.1007\/s11356-020-10054-1","article-title":"Exploitation of new approach to control of environmental pathogenic bacteria causing bovine clinical mastitis using novel anti-biofilm nanocomposite","volume":"27","author":"Mohammed","year":"2020","journal-title":"Environ. Sci. Pollut. Res. Int."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"275","DOI":"10.4081\/ijas.2003.275","article-title":"Effects of automatic milking system on teat tissues, intramammary infections and somatic cell counts","volume":"2","author":"Zecconi","year":"2003","journal-title":"Ital. J. Anim. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"273","DOI":"10.3389\/fvets.2018.00273","article-title":"Assessing financial impacts of subclinical mastitis on Colombian dairy farms","volume":"5","author":"Romero","year":"2018","journal-title":"Front. Vet. Sci."},{"key":"ref_21","unstructured":"Quinn, P.J., Markey, B.K., Leonard, F.C., Hartigan, P., Fanning, S., and Fitzpatrick, E. (2011). Veterinary Microbiology and Microbial Disease, John Wiley & Sons. [2nd ed.]."},{"key":"ref_22","unstructured":"NMC (2017). Laboratory Handbook on Bovine Mastitis, National Mastitis Council Inc.. [3rd ed.]."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.vetmic.2011.04.006","article-title":"CNS species and antimicrobial resistance in clinical and subclinical bovine mastitis","volume":"152","author":"Waller","year":"2011","journal-title":"Vet. Microbiol."},{"key":"ref_24","unstructured":"CLSI (Clinical and Laboratory Standards Institute) (2018). Performance Standards for Antimicrobial Susceptibility Testing, Clinical and Laboratory Standards Institute.M100. [28th ed.]."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1264\/jsme2.23.153","article-title":"Prevalence of multiple drug-resistant Escherichia coli serotypes in a tropical estuary, India","volume":"23","author":"Chandran","year":"2008","journal-title":"Microbes Environ."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1141","DOI":"10.1128\/JCM.44.3.1141-1144.2006","article-title":"Novel multiplex PCR assay for detection of the staphylococcal virulence marker Panton-Valentine leukocidin genes and simultaneous discrimination of methicillin-susceptible from-resistant staphylococci","volume":"44","author":"McClure","year":"2006","journal-title":"J. Clin. Microbiol."},{"key":"ref_27","first-page":"389","article-title":"Antibiotic resistance genes & susceptibility patterns in staphylococci","volume":"135","author":"Duran","year":"2012","journal-title":"Indian J. Med Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1007\/s11250-009-9360-5","article-title":"Evaluation of PCR test for detecting major pathogens of bubaline mastitis directly from mastitic milk samples of buffaloes","volume":"41","year":"2009","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1590\/S1517-83822009000200009","article-title":"Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis","volume":"40","author":"Ciftci","year":"2009","journal-title":"Braz. J. Microbiol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1423","DOI":"10.1128\/AAC.47.4.1423-1426.2003","article-title":"Multiplex PCR for detection of aminoglycoside resistance genes in enterococci","volume":"47","author":"Vakulenko","year":"2003","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1788","DOI":"10.1128\/AAC.38.8.1788","article-title":"Analysis of genes encoding D-alanine-D-alanine ligase-related enzymes in Enterococcus casseliflavus and Enterococcus flavescens","volume":"38","author":"Navarro","year":"1994","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4473","DOI":"10.1128\/JCM.42.10.4473-4479.2004","article-title":"Development of a multiplex PCR for the detection of asa1, gelE, cylA, esp, and hyl genes in enterococci and survey for virulence determinants among European hospital isolates of Enterococcus faecium","volume":"42","author":"Vankerckhoven","year":"2004","journal-title":"J. Clin. Microbiol."},{"key":"ref_33","first-page":"282","article-title":"Screening of group B Streptococcus agalactiae virulence factors (scpB, sip, cfb) in Iraqi pregnant women","volume":"20","author":"Abbas","year":"2020","journal-title":"Plant. Arch."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1093\/jac\/dkh070","article-title":"Antibiotic resistance genes, integrons and multiple antibiotic resistance in thirty-five serotypes of Salmonella enterica isolated from humans and animals in the UK","volume":"53","author":"Randall","year":"2004","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Ibekwe, A.M., Murinda, S.E., and Graves, A.K. (2011). Genetic diversity and antimicrobial resistance of Escherichia coli from human and animal sources uncovers multiple resistances from human sources. PLoS ONE, 6.","DOI":"10.1371\/journal.pone.0020819"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"91","DOI":"10.3844\/ajavsp.2010.91.96","article-title":"Determination of adhesin encoding genes in Escherichia coli isolates from omphalitis of chicks","volume":"5","author":"Ghanbarpour","year":"2010","journal-title":"Am. J. Anim. Vet. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/S0378-1135(03)00076-2","article-title":"Virulence-associated genes in Escherichia coli isolates from poultry with colibacillosis","volume":"94","author":"Delicato","year":"2003","journal-title":"Vet. Microbiol."},{"key":"ref_38","first-page":"321","article-title":"Subclinical mastitis in dairy cattle and buffaloes among small holders in Egypt: Prevalence and evidence of virulence of Escherichia coli causative agent","volume":"35","author":"Ahmed","year":"2018","journal-title":"Trop. Biomed."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1750","DOI":"10.14202\/vetworld.2020.1750-1759","article-title":"Financial and economic analyses of the impact of cattle mastitis on the profitability of Egyptian dairy farms","volume":"13","author":"Azooz","year":"2020","journal-title":"Vet. World"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.prevetmed.2019.03.001","article-title":"Economic and epidemiological impact of different intervention strategies for subclinical and clinical mastitis","volume":"166","author":"Gussmann","year":"2019","journal-title":"Prev. Vet. Med."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"108570","DOI":"10.1016\/j.vetmic.2019.108570","article-title":"Prevalence, etiology, and economic impact of clinical mastitis on large dairy farms in China","volume":"242","author":"He","year":"2020","journal-title":"Vet. Microbiol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"5652","DOI":"10.3168\/jds.2020-19366","article-title":"Partial budget analysis of culture-and algorithm-guided selective dry cow therapy","volume":"104","author":"Rowe","year":"2021","journal-title":"J. Dairy Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"6545","DOI":"10.3168\/jds.2016-12042","article-title":"Estimation of prevalence and incidence of subclinical mastitis in a large population of Brazilian dairy herds","volume":"100","author":"Busanello","year":"2017","journal-title":"J. Dairy Sci."},{"key":"ref_44","first-page":"1497","article-title":"Prevalence of bovine subclinical mastitis, its etiology and diagnosis of antibiotic resistance of dairy farms in four municipalities of a tropical region of Mexico","volume":"47","author":"Kholif","year":"1497","journal-title":"Trop. Anim. Health Prod"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Samuel, T.M., De Castro, C.A., Dubascoux, S., Affolter, M., Giuffrida, F., Billeaud, C., Picaud, J.-C., Agosti, M., Al-Jashi, I., and Pereira, A.B. (2020). Subclinical mastitis in a European multicenter cohort: Prevalence, impact on human milk (HM) composition, and association with infant HM intake and growth. Nutrients, 12.","DOI":"10.3390\/nu12010105"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"2413","DOI":"10.1007\/s11250-019-01957-4","article-title":"Influence of bovine sub-clinical mastitis and associated risk factors on calving interval in a population of cross-bred lactating cows in Sri Lanka","volume":"51","author":"Rahularaj","year":"2019","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"429","DOI":"10.5713\/ajas.2011.10233","article-title":"Relationship of somatic cell count and mastitis: An overview","volume":"24","author":"Sharma","year":"2011","journal-title":"Asian Australas. J. Anim. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Dos Reis, C.B.M., Barreiro, J.R., Mestieri, L., de Fel\u00edcio Porcionato, M., and dos Santos, M.V. (2013). Effect of somatic cell count and mastitis pathogens on milk composition in Gyr cows. BMC Vet. Res., 9.","DOI":"10.1186\/1746-6148-9-67"},{"key":"ref_49","first-page":"205","article-title":"The effect of subclinical mastitis on milk composition in dairy cows","volume":"8","author":"Batavani","year":"2007","journal-title":"Iran. J. Vet. Res. Univ. Shiraz."},{"key":"ref_50","unstructured":"Shereen, S.I. (2009). Lactate Dehydrogenase Activity and Other Factors in Milk as Markers for Bovine Mastitis: Correlation with the Associated Bacterial Pathogens. [Master\u2019s Thesis, Cairo University]."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"38","DOI":"10.21608\/avmj.2013.171607","article-title":"A contribution towards milk enzymes, somatic cell count and bacterial pathogens associated with subclinical mastitis cows milk","volume":"59","author":"Zeinhom","year":"2013","journal-title":"Assiut. Vet. Med. J."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Birhanu, M., Leta, S., Mamo, G., and Tesfaye, S. (2017). Prevalence of bovine subclinical mastitis and isolation of its major causes in Bishoftu Town, Ethiopia. BMC Res. Notes, 10.","DOI":"10.1186\/s13104-017-3100-0"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1007\/s11250-018-1777-2","article-title":"Assessment of risk factors and isolation of Staphylococcus aureus and Escherichia coli from bovine subclinical mastitic milk in and around Gondar, Northwest Ethiopia","volume":"51","author":"Bihon","year":"2019","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_54","first-page":"9","article-title":"Quarter-wise comparative prevalence of mastitis in buffaloes and cross-bred cows","volume":"25","author":"Khan","year":"2005","journal-title":"Pak. Vet. J."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"298","DOI":"10.3923\/pjbs.2017.298.305","article-title":"Genetic characterization, antimicrobial resistance patterns and virulence determinants of Staphylococcus aureus isolated from bovine mastitis","volume":"20","author":"Awad","year":"2017","journal-title":"Pak. J. Biol. Sci."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1136\/vr.163.1.16","article-title":"Prevalence of subclinical mastitis and associated risk factors in smallholder dairy cows in Tanzania","volume":"163","author":"Karimuribo","year":"2008","journal-title":"Vet. Rec."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1515\/acve-2015-0030","article-title":"Investigation on the etiology of subclinical mastitis in Jersey and hybrid Jersey dairy cows","volume":"65","author":"Findik","year":"2015","journal-title":"Acta Vet."},{"key":"ref_58","first-page":"319","article-title":"Prevalence of antimicrobial resistance among bacterial pathogens isolated from bovine mastitis in northern Jordan","volume":"164","author":"Alekish","year":"2013","journal-title":"Rev. Med. Vet."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1515\/pjvs-2016-0015","article-title":"Prevalence and etiological agents of subclinical mastitis at the end of lactation in nine dairy herds in North-East Poland","volume":"19","author":"Janowski","year":"2016","journal-title":"Pol. J. Vet. Sci."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.prevetmed.2017.06.009","article-title":"Prevalence of subclinical mastitis and associated risk factors at cow and herd level in dairy farms in North-West Ethiopia","volume":"145","author":"Mekonnen","year":"2017","journal-title":"Prev. Vet. Med."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"2037","DOI":"10.1007\/s11250-019-01905-2","article-title":"Aetiology and prevalence of subclinical mastitis in dairy herds in peri-urban areas of Kigali in Rwanda","volume":"51","author":"Ndahetuye","year":"2019","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1007\/s11250-013-0455-7","article-title":"Prevalence of subclinical mastitis in dairy farms in urban and peri-urban areas of Kampala, Uganda","volume":"46","author":"Persson","year":"2014","journal-title":"Trop. Anim. Health Prod."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"13","DOI":"10.5897\/JVMAH2013.0259","article-title":"Prevalence of clinical and sub-clinical mastitis on cross-bred dairy cows at Holleta Agricultural Research Center, Central Ethiopia","volume":"6","author":"Duguma","year":"2014","journal-title":"J. Vet. Med. Anim. Health."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"4868","DOI":"10.3168\/jds.2016-12353","article-title":"Associations between pathogen-specific cases of subclinical mastitis and milk yield, quality, protein composition, and cheese-making traits in dairy cows","volume":"100","author":"Bobbo","year":"2017","journal-title":"J. Dairy Sci."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"2247","DOI":"10.3168\/jds.2012-6091","article-title":"Genetic characterization of antimicrobial resistance in coagulase-negative staphylococci from bovine mastitis milk","volume":"96","author":"Frey","year":"2013","journal-title":"J. Dairy Sci."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"234","DOI":"10.3168\/jds.2012-5795","article-title":"Characterization of the ability of coagulase-negative staphylococci isolated from the milk of Canadian farms to form biofilms","volume":"96","author":"Tremblay","year":"2013","journal-title":"J. Dairy Sci."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"2329","DOI":"10.3168\/jds.2010-3741","article-title":"Some coagulase-negative Staphylococcus species affect udder health more than others","volume":"94","author":"Haesebrouck","year":"2011","journal-title":"J. Dairy Sci."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"35","DOI":"10.14419\/ijbr.v2i2.2835","article-title":"Prevalence of subclinical mastitis and its association with bacteria and risk factors in lactating cows of Barisal district in Bangladesh","volume":"2","author":"Kayesh","year":"2014","journal-title":"Int. J. Biol. Res."},{"key":"ref_69","first-page":"2313","article-title":"Prevalence of bovine subclinical mastitis and its association with bacteria and risk factors in milking cows of Batticaloa District in Sri Lanka","volume":"3","author":"Sanotharan","year":"2016","journal-title":"Int. J. Sci. Res. Innov. Technol."},{"key":"ref_70","first-page":"1","article-title":"The isolation of streptococcal agents from cattle with subclinical mastitis in Hatay region and detection of their susceptibilities against some antibiotics","volume":"2","author":"Acar","year":"2012","journal-title":"AVKAE Derg."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"e59","DOI":"10.1111\/j.1863-2378.2009.01307.x","article-title":"Antimicrobial resistance of enterococci isolated from mastitic bovine milk samples in Korea","volume":"57","author":"Nam","year":"2010","journal-title":"Zoonoses Public Health"},{"key":"ref_72","first-page":"190","article-title":"Occurrence, forms and etiologic agents of mastitis in Poland depending on size of farm","volume":"67","author":"Smulski","year":"2011","journal-title":"Med. Weter."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"ftw006","DOI":"10.1093\/femspd\/ftw006","article-title":"Bovine mastitis disease\/pathogenicity: Evidence of the potential role of microbial biofilms","volume":"74","author":"Gomes","year":"2016","journal-title":"Pathog. Dis."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"3368","DOI":"10.3168\/jds.2019-17420","article-title":"Prevalence and characterization of Staphylococcus aureus isolates from subclinical bovine mastitis in southern Xinjiang, China","volume":"103","author":"Ren","year":"2020","journal-title":"J. Dairy Sci."},{"key":"ref_75","doi-asserted-by":"crossref","unstructured":"Srednik, M.E., Tremblay, Y.D.N., Labrie, J., Archambault, M., Jacques, M., Alicia, F.C., and Gentilini, E.R. (2017). Biofilm formation and antimicrobial resistance genes of coagulase-negative staphylococci isolated from cows with mastitis in Argentina. FEMS Microbiol. Lett., 364.","DOI":"10.1093\/femsle\/fnx001"},{"key":"ref_76","unstructured":"Youssif, N.H., Hafiz, N.M., Halawa, M.A., and Aziz, H.M. (2019). Genes conferring antimicrobial resistance in cattle with subclinical mastitis. Bulg. J. Vet. Med., 1\u201319."},{"key":"ref_77","first-page":"706","article-title":"Prevalence, bacterial etiology and antibiotic susceptibility pattern of bovine mastitis in Meerut","volume":"6","author":"Verma","year":"2018","journal-title":"J. Entomol. Zool. Stud."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"688","DOI":"10.1128\/JCM.05214-11","article-title":"Prevalence and characterization of Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus, isolated from bulk tank milk from Minnesota dairy farms","volume":"50","author":"Haran","year":"2012","journal-title":"J. Clin. Microbiol."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"4382","DOI":"10.3168\/jds.2011-5198","article-title":"Prevalence, antimicrobial resistance, and molecular characterization of methicillin-resistant Staphylococcus aureus from bulk tank milk of dairy herds","volume":"95","author":"Kreausukon","year":"2012","journal-title":"J. Dairy Sci."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s12941-017-0210-4","article-title":"Antimicrobial resistance and virulence characterization of Staphylococcus aureus and coagulase-negative staphylococci from imported beef meat","volume":"16","author":"Osman","year":"2017","journal-title":"Ann. Clin. Microbiol. Antimicrob."},{"key":"ref_81","doi-asserted-by":"crossref","unstructured":"Gajewska, J., and Chaj\u0119cka-Wierzchowska, W. (2020). Biofilm formation ability and presence of adhesion genes among coagulase-negative and coagulase-positive Staphylococci isolates from raw cow\u2019s milk. Pathogens, 9.","DOI":"10.3390\/pathogens9080654"},{"key":"ref_82","first-page":"2009","article-title":"Relevance of biofilm formation and virulence of different species of coagulase-negative staphylococci to public health","volume":"34","author":"Osman","year":"2015","journal-title":"Clin. Microbiol. Infect. Dis."},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.vetmic.2015.02.024","article-title":"Virulence, persistence and dissemination of Mycoplasma bovis","volume":"179","author":"Burki","year":"2015","journal-title":"Vet. Microbiol."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1016\/j.jcpa.2010.12.005","article-title":"Detection of Mycoplasma bovis by in-situ hybridization and expression of inducible nitric oxide synthase, nitrotyrosine and manganese superoxide dismutase in the lungs of experimentally infected calves","volume":"145","author":"Hermeyer","year":"2011","journal-title":"J. Comp. Pathol."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.ijfoodmicro.2012.12.028","article-title":"Biocide tolerance in bacteria","volume":"162","author":"Morente","year":"2013","journal-title":"Int. J. Food Microbiol."},{"key":"ref_86","first-page":"308","article-title":"High frequency of hemolysin associated genes among Staphylococcus aureus clinical isolates in Iraq","volume":"12","year":"2017","journal-title":"J. Glob. Pharm. Technol."},{"key":"ref_87","first-page":"326","article-title":"Characterization of hemolysins of Staphylococcus strains isolated from human and bovine, southern Iran","volume":"15","author":"Moraveji","year":"2014","journal-title":"Iran. J. Vet. Res."},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1590\/S1517-83822013000200026","article-title":"Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the northeast of Brazil","volume":"44","author":"Almeida","year":"2013","journal-title":"Braz. J. Microbiol."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"238","DOI":"10.21608\/bvmj.2016.31368","article-title":"Molecular detection of some virulence genes of S. aureus isolated from mastitic Cows by PCR","volume":"30","author":"Maarouf","year":"2016","journal-title":"Benha Vet. Med J."},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"162","DOI":"10.3109\/13880209.2015.1025290","article-title":"Antimicrobial resistance and virulence-related genes of Streptococcus obtained from dairy cows with mastitis in Inner Mongolia, China","volume":"54","author":"Ding","year":"2016","journal-title":"Pharm. Biol."},{"key":"ref_91","doi-asserted-by":"crossref","first-page":"4725","DOI":"10.1128\/IAI.67.9.4725-4731.1999","article-title":"Identification, cloning, and expression of the CAMP factor gene (cfa) of group A streptococci","volume":"67","author":"Gase","year":"1999","journal-title":"Infect. Immun."},{"key":"ref_92","first-page":"145","article-title":"Molecular studies regarding to virulence factors of Streptococcus species isolated from raw milk","volume":"32","author":"Abdullah","year":"2017","journal-title":"Benha Vet. Med J."},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"34","DOI":"10.21608\/avmj.2020.168456","article-title":"Bacteriological and molecular studies on E. coli isolated from broiler chickens","volume":"66","author":"Hassan","year":"2020","journal-title":"Assiut Vet. Med. J."},{"key":"ref_94","first-page":"1","article-title":"Phenotypic and genotypic characterization of virulence factors of Escherichia coli isolated from broiler chickens with simultaneous occurrence of cellulites and other colibacillosis lesions","volume":"65","author":"Gomis","year":"2001","journal-title":"Can. J. Vet. Res."},{"key":"ref_95","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1590\/S0100-736X2009000700001","article-title":"Virulence factors of avian pathogenic Escherichia coli (APEC)","volume":"29","author":"Nakazato","year":"2009","journal-title":"Pesq Vet. Bras."},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"298","DOI":"10.1080\/030794504200020399","article-title":"Significance of interactions between Escherichia coli and respiratory pathogens in layer hen flocks suffering from colibacillosis -associated mortality","volume":"33","author":"Vandekerchove","year":"2004","journal-title":"Avian Pathol."},{"key":"ref_97","doi-asserted-by":"crossref","first-page":"e17520","DOI":"10.5812\/jjm.17520","article-title":"The fimH gene in uropathogenic Escherichia coli strains isolated from patients with urinary tract infection","volume":"8","author":"Hojati","year":"2015","journal-title":"Jundishapur J. Microbiol."},{"key":"ref_98","doi-asserted-by":"crossref","first-page":"1373","DOI":"10.1128\/AEM.01253-08","article-title":"Associations between antimicrobial resistance phenotypes, antimicrobial resistance genes, and virulence genes of fecal Escherichia coli isolates from healthy grow-finish pigs","volume":"75","author":"Rosengren","year":"2009","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_99","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1186\/s13756-019-0505-7","article-title":"Phenotypic and genotypic characterization of antibiotic resistance in the methicillin-resistant Staphylococcus aureus strains isolated from hospital cockroaches","volume":"8","author":"Abdolmaleki","year":"2019","journal-title":"Antimicrob Resist Infect Control."},{"key":"ref_100","doi-asserted-by":"crossref","first-page":"232","DOI":"10.4103\/ijmr.IJMR_2097_17","article-title":"Phenotypic & genotypic study of antimicrobial profile of bacteria isolates from environmental samples","volume":"149","author":"Shivakumaraswamy","year":"2019","journal-title":"Indian J. Med. Res."},{"key":"ref_101","doi-asserted-by":"crossref","unstructured":"Jaja, I.F., Oguttu, J., Jaja, C.-J.I., and Green, E. (2020). Prevalence and distribution of antimicrobial resistance determinants of Escherichia coli isolates obtained frommeat in South Africa. PLoS ONE, 15.","DOI":"10.1371\/journal.pone.0216914"},{"key":"ref_102","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.eng.2019.10.014","article-title":"Association between the phenotypes and genotypes of antimicrobial resistance in Haemophilus parasuis isolates from swine in Quang Binh and Thua Thien Hue Provinces, Vietnam","volume":"6","author":"Van","year":"2020","journal-title":"Engineering."},{"key":"ref_103","doi-asserted-by":"crossref","first-page":"2863","DOI":"10.2147\/IDR.S262493","article-title":"Genotypic to phenotypic resistance discrepancies identified involving \u03b2-lactamase genes, blaKPC, blaIMP, blaNDM-1, and blaVIM in uropathogenic Klebsiella pneumoniae","volume":"13","author":"Urmi","year":"2021","journal-title":"Infect. Drug Resist."},{"key":"ref_104","doi-asserted-by":"crossref","first-page":"6753","DOI":"10.1128\/AEM.71.11.6753-6761.2005","article-title":"Antimicrobial resistance and virulence genes of Escherichia coli isolates from swine in Ontario","volume":"71","author":"Boerlin","year":"2005","journal-title":"Appl. Environ. Microbiol."}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/9\/6\/1175\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:08:54Z","timestamp":1760162934000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/9\/6\/1175"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,29]]},"references-count":104,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2021,6]]}},"alternative-id":["microorganisms9061175"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms9061175","relation":{},"ISSN":["2076-2607"],"issn-type":[{"value":"2076-2607","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,29]]}}}