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.

Atypical mandibular osteomyelitis in an ewe caused by coinfection of Pseudomonas aeruginosa and Lactococcus raffinolactis

Background: Osteomyelitis is defined as a bone inflammation involving the cortical and medullary regions, usually caused by the local invasion of opportunistic microorganisms. The inflammatory reaction of bone may extend to the periosteum and soft tissues, compromising adjacent structures far from the initially infected foci. Different classifications of transmission routes, gravity levels, and tissues involved in animal and human osteomyelitis are available. In humans, the infection can reach bone tissue by exogenous or hematogenous pathways. This paper reports an atypical case of mandibular pyogranulomatous osteomyelitis in an ewe caused by concomitant Pseudomonas aeruginosa and Lactococcus raffinolactis infection. Case: The animal presented a 1-month history of progressive mandibular enlargement refractory to conventional therapy. In a physical examination, an increased volume located in the ventrolateral region of the right ramus of the mandible was observed. Fine-needle aspiration of the lesion enabled isolation in bacteriological culture of Pseudomonas aeruginosa and Lactococcus raffinolactis using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDITOF MS). Besides support care procedures and antimicrobial treatment approaches for the sheep based on in vitro tests, the animal died due to the severity of the clinical signs and the progressive worsening of the general health status. The radiographic image examination of the mandibular region revealed a severe and infiltrative periodontal reaction, with a predominance of a great number of neutrophils and macrophages, necrotic areas, and bone destruction, characterized histologically as a pyogranulomatous rection. At post mortem examination, a large pyogranuloma was observed in the entire horizontal branch of the mandible as well, showing a dark yellowish content of coarse consistency, caseous appearance, and bone fragmentation. Discussion: Ovine mandibular osteomyelitis is a well-established bone inflammation involving the cortical and medullary regions, characterized clinically by local enlargement, asymmetry, pain sensitivity, edema, hyperthermia, infiltrate caseous or suppurative material, and bone rarefaction. In the current report, 1-month history of progressive enlargement of the mandibular region, prostration, and weight loss in an ewe were referred. Where clinical and epidemiological features, bacteriological, cytological, histological, and mass spectrometry diagnostic approaches were assessed to diagnostic. Most reports involving the etiology of ovine mandibular osteomyelitis have been diagnosed based on classical phenotypic tests. Here, the concomitant identification of P. aeruginosa and L. raffinolactis infection was possible using mass spectrometry (MALDI-TOF), highlighting the importance of molecular methods in the diagnosis of animal diseases. In addition, the differentiation between Lactococcus and Enterococcus species is difficult, which could underestimate the diagnosis of Lactococcus species as a primary pathogen from animal diseases. We report, for the first time, a fatal case of mandibular pyogranulomatous osteomyelitis in a sheep caused by Pseudomonas aeruginosa and Lactococcus raffinolactis coinfection.