In Vitro Activity of Quaternary Ammonium in Prototheca Isolated from Clinical Bovine Mastitis Identified by Mass Spectrometry and PCR Sequencing of the cytb Gene Marker.

The in vitro algaecide activity of quaternary ammonium (QA) against Prototheca isolated from bovine clinical mastitis was investigated, in which the clinical severity was scored, milk samples were subjected to microbiological culture, and algal species were identified by molecular typing. A total of 4275 milk clinical samples of different cows from ten large dairy farms were used. Forty-four (1%) samples of cows from three dairy farms yielded growth of Prototheca, of which 88.6% (39/44) were identified as Prototheca bovis and 11.3% (5/44) as Prototheca sp. by MALDI-TOF MS, whereas 100% of the isolates were identified as P. bovis using PCR sequencing of the cytb gene. Among cows for which clinical severity scoring was available, 78.8% (26/33) and 21.2% (7/33) had mild and moderate infections, respectively, whereas no animal showed severe clinical signs. The algaecide activity of QA in Prototheca was observed in low concentrations among all isolates, in 20.4% (9/44) at 35 ppm, 36.4% (16/44) at 17 ppm, and 43.2% (19/44) at an 8 ppm, in addition to activity on three reference Prototheca strains. Overall, the study highlights the predominance of P. bovis as the causative agent of algal mastitis in bovines. Prototheca induced abnormalities preponderantly in the milk and mammary gland tissue of cows, and to our knowledge, our study is the first to apply clinical severity scoring in protothecal mastitis. In addition, the study underlines the activity of QA in low concentrations against Prototheca, indicating its potential use as an antiseptic/disinfectant in milking facilities and dairy environments.

Diagnosis failure of bovine leukosis: serology variation during the peripartum period.

This study demonstrates the influence of pregnancy on serum diagnosis of enzootic bovine leukosis (EBL), emphasizing the importance of routine testing to maintain herd health. For this, 143 pregnant cows were sampled in duplicate (30 days before and 15 days after calving). For EBL diagnosis, samples were submitted to agar gel immunodiffusion testing (AGID). Different results were observed before and after delivery in seventy-six serum samples (53.15%), indicating variations in the levels of serum globulins in the blood during the peripartum period. Therefore, using a single sample for serological diagnosis during the birth season might not represent the correct infection status of animal health due to physiological variations in antibody concentrations.

Phenotypic and molecular identification of Brucella suis biotype 1 in a pig from Brazil-case report.

Brucellosis is a zoonotic disease with a global impact. Brucella suis is one of the most pathogenic species to humans, requiring different measures for the control and/or eradication of the disease. The serological investigation for brucellosis was performed in pigs, horses, dogs, and cattle on a farm with a history of abortion in sows and necropsy of a boar with severe necrosuppurative orchitis. One sow, two cows, and two dogs reveled positive to Rose Bengal Test (RBT), although only the sow had a confirmatory outcome in 2-mercaptoethanol (2-ME). The 2-ME-positive sow was euthanized and microbiological culture of lymph nodes and liver followed by biochemical characterization allowed phenotypic characterization of Brucella suis biotype 1. PCR multiplex Bruce-ladder and Suis-ladder enabled molecular confirmation, respectively, of Brucella suis and biotype 1. The transmission aspects of B. suis to pigs and other domestic species, the combination of diagnostic procedures to diagnosis, as well as human health concerns of brucellosis are discussed.