Survival patterns of Streptococcus suis serotypes 1 and 14 in porcine blood indicate cross-reactive bactericidal antibodies in naturally infected pigs.

Streptococcus suis serotype (cps) 1 and cps14 have been detected in association with severe diseases such as meningitis and polyarthritis in pigs. Though these two cps are very similar, only cps14 is an important zoonotic agent in Asia and only cps1 is described to be associated with diseases in suckling piglets rather than weaning piglets. The main objective of this study was to assess restriction of survival of cps14 and cps1 in porcine blood by IgG and IgM putatively cross-reacting with these two cps. Furthermore, we differentiate recent European cps1/14 strains by agglutination, cpsK sequencing, MLST and virulence-associated gene profiling. Our data confirmed cps1 of clonal complex 1 as an important pathotype causing polyarthritis in suckling piglets in Europe. The experimental design included also bactericidal assays with blood samples drawn at different ages of piglets naturally infected with different S. suis cps types including cps1 but not cps14. We report survival of a cps1 and a cps14 strain (both of sequence type 1) in blood of suckling piglets with high levels of maternal IgG binding to the bacterial surface. In contrast, killing of cps1 and cps14 was recorded in older piglets due to an increase of IgM as demonstrated by specific cleavage of IgM. Heterologous absorption of antibodies with cps1 or cps14 is sufficient to significantly increase the survival of the other cps. In conclusion, IgM elicited by natural S. suis infection is crucial for killing of S. suis cps1 and cps14 in older weaning piglets and has most likely the potential to cross-react between cps1 and cps14.

Unusual case of polyarthritis and hepatorenal syndrome associated with Leptospira interrogans infection in a dog: A case report.

Leptospirosis is a zoonotic disease caused by spirochetal bacterial of the genus Leptospira affecting virtually all mammals. The infection has a broad range of effects, from mild clinical manifestation to multiple organ failure, and ultimately death. A 5-months-old male unvaccinated dog was admitted to the University Veterinary Teaching Hospital presenting dullness, dehydration, jaundiced mucous, bloody diarrhea, vomiting, and hyporexia. Microscopic agglutination test (MAT) detected serological titers of 1:1.600 for serogroup Canicola. After five days of monitoring by the medical team he developed fever and swelling of carpal and tarsal joints, accompanied by functional limitation. Initial antimicrobial treatment was instituted for leptospirosis. Polyarthritis responsiveness to glucocorticoid therapy was observed through decreasing signs of inflammation of the affected joints. The diagnosis of leptospirosis was further confirmed by molecular investigation for Leptospira spp. on blood and synovial fluid samples. Amplification and sequencing of the secY partial gene characterized the infective bacterial as Leptospira interrogans. From the 7th day the respiratory condition worsened and on Day 14 the patient evolved to death, when necropsy and histological evaluation were performed. Prominent anatomopathological findings included: fibrinous polyarthritis, bronchointerstitial pneumonia, intense hepatocyte dissociation, cholestasis, and periportal multifocal hepatitis, diffuse acute tubular necrosis, and significant dystrophic mineralization in the renal parenchyma, lungs, and atrial endocardium. Here, we present a case report of systemic clinical manifestations polyarthritis associated with the presence of leptospiras in the synovial fluid. We highlight the need for richer knowledge about the different clinical manifestations of leptospirosis.

Invasion of Mycoplasma bovis into bovine synovial cells utilizing the clathrin-dependent endocytosis pathway.

Mycoplasma bovis causes chronic arthritis in cattle, accompanied by a severe inflammatory reaction of the joints. Recent studies demonstrated that M. bovis can invade bovine non-phagocytic cells, but the mechanism of M. bovis internalization in the cells remains unclear. In this study, we examined the mechanism by which M. bovis invades synovial cells, including the pathway of cell invasion. Using fluorescence and electron microscopy, multiple M. bovis were observed to adhere to and be internalized in cultured bovine synovial cells. The number of M. bovis colocalized with clathrin heavy chain (CLTC) per cell was significantly higher than the number of M. bovis colocalized with caveolin-1 (Cav-1). The internalized ratio of M. bovis in synovial cells treated with clathrin-dependent endocytosis inhibitor and small interfering RNA (siRNA) against CLTC was significantly lower than that in control cells. In contrast, the internalized ratio of M. bovis in synovial cells was unaffected by siRNA against Cav-1. These findings provide the first evidence that clathrin-dependent endocytosis is one of the major pathways by which M. bovis invades into synovial cells.

Granulomatous polyarthritis caused by Talaromyces georgiensis in a dog.

A 6-y-old, 3.5-kg, spayed female Toy Poodle was presented with left forelimb lameness of 2-d duration. Two months before the initial presentation, radiography showed osteolysis of the medial epicondyle of the left humerus, and the left forelimb was amputated. Grossly, the articular villi of the elbow joint were markedly thickened, and the articular cartilage surfaces of the distal humerus and proximal radius had partial erosion. Histologically, granulomatous arthritis and osteomyelitis characterized by the presence of abundant macrophages containing numerous fungi were observed. ITS and ß-tubulin sequences amplified from the isolate from the specimen were 100% and 99% identical to type strain UTHSC D16-145T of Talaromyces georgiensis, respectively. Canine osteoarthritis caused by T. georgiensis has not been reported previously, to our knowledge.

Polyarthritis Caused by Acinetobacter kookii in a Rothschild's Giraffe Calf (Giraffa camelopardalis rothschildi).

We report the first isolation of Acinetobacter kookii from a Rothschild's giraffe calf (Giraffa camelopardalis rothschildi) that had severe polyarthritis. The isolate was resistant to more than one representative of each of four classes of antibiotics (penicillins, macrolides, lincosamides and tetracyclines). As A. kookii has not been previously associated with disease in humans or animals, it may be an emerging opportunistic pathogen posing a threat to immunocompromised patients. Furthermore, as transmission of Acinetobacter spp. with similar patterns of antimicrobial resistance has been previously reported in human and animal populations, special care should be taken when handling infected animals.

Molecular detection of Mycoplasma synoviae and avian reovirus infection in arthritis and tenosynovitis lesions of broiler and breeder chickens in Santa Catarina State, Brazil.

Infectious arthritis or tenosynovitis in broiler and breeder chickens results in major loss of productivity because of reduced growth and downgrading at processing plants. The most common causative agents of avian infectious arthritis are the bacterium Mycoplasma synoviae and avian reoviruses (ARVs) (family Reoviridae, genus Orthoreovirus). In this study, we evaluated the occurrence of these two pathogens in arthritis or tenosynovitis lesions of broilers and breeder flocks in southern Brazil using molecular detection. Tissue sections from tibiotarsal joints with visible lesions from 719 broilers and 505 breeders were analysed using pathogen-specific polymerase chain reaction (PCR) assays. In breeders, 41.2% (n = 296) of lesions were positive for M. synoviae, 26.4% (n = 190) were positive for ARV, while co-infection was present in 12.2% (n = 88) of the samples. In broilers, 20.8% (n = 105) of lesions were positive for M. synoviae, 11.9% (n = 60) for ARV and 7.7% (n = 39) of these cases were positive for both pathogens. Post-mortem examination revealed lesions with varying degrees of gross pathological severity. Histopathological examination showed intense, diffuse lymphohistiocytic inflammatory infiltrates with heterophil accumulation, primarily in the synovial capsule and digital flexor tendon, in all samples. Improved strategies for early detection and control of these major avian pathogens are highly desirable for preventing the spread of infection and reducing economic losses in the poultry industry.

An outbreak of Mycoplasma mycoides subspecies capri arthritis in young goats: a case study.

Mycoplasmosis is a well-known cause of morbidity and mortality in small ruminants. Previously recognized outbreaks have involved arthritis, and pneumonia or pleuropneumonia. Modern bacteriology procedures rely less on isolation techniques that require special media for mollicutes given that these species are notoriously difficult to isolate, and rely more on PCR tests. We report an outbreak of arthritis, pleuropneumonia, and mild meningitis affecting dairy goat kids, spanning a period of 3 y, which had unusual epidemiologic characteristics related to husbandry practices. Lesions were characterized by polyarthritis of the appendicular joints, with copious joint fluid and extension of arthritic exudate beyond the joint itself. The cause remained unknown until serendipitous isolation of a mycoplasma on blood agar. Mycoplasmosis was not detected from synovial samples by a general mycoplasma PCR, despite multiple attempts. Isolated colonies were also negative by this general PCR assay. The isolate was identified as Mycoplasma mycoides subspecies capri, using universal 16S primers and amplicon sequencing. Testing of additional isolates from other diseased goats in the herd confirmed that this was the cause of illness. A failure to recognize the distinct nature of organisms of the M. mycoides group of mycoplasmas meant that a PCR test that cannot detect this group of organisms was utilized at first, and the etiology of the illness was overlooked for a period of time. Veterinary pathologists and microbiologists must be aware of the limitations of some PCR assays when confronted with joint disease and pleuropneumonia in small ruminants.

Comparative immunosecretome analysis of prevalent Streptococcus suis serotypes.

Streptococcus suis is a major Gram-positive swine pathogen associated with a wide variety of diseases in pigs. The efforts made to develop vaccines against this pathogen have failed because of lack of common cross-reactive antigens against different serotypes. Nowadays the interest has moved to surface and secreted proteins, as they have the highest chances to raise an effective immune response because they are in direct contact with host cells and are really exposed and accessible to antibodies. In this work, we have performed a comparative immunosecretomic approach to identify a set of immunoreactive secreted proteins common to the most prevalent serotypes of S. suis. Among the 67 proteins identified, three (SSU0020, SSU0934, and SSU0215) were those predicted extracellular proteins most widely found within the studied serotypes. These immunoreactive proteins may be interesting targets for future vaccine development as they could provide possible cross-reactivity among different serotypes of this pathogen.

Age susceptibility of caesarian derived colostrum deprived pigs to Mycoplasma hyorhinis challenge.

Mycoplasma hyorhinis (MHR) is a major cause of lameness, arthritis, and polyserositis among growing pigs. Reduced performance and culling due to MHR infection result in economic losses in swine production. We have previously developed an MHR challenge model in seven week-old CDCD pigs using cell-associated challenge material which results in both severe pericarditis and lameness. In this study we sequentially challenged CDCD pigs at seven, ten, thirteen, and sixteen weeks of age. Lameness was observed in >60% of the animals in the first three age groups but only 33% in the oldest age group. The number of animals with arthritis declined from 100% at seven weeks, to 56% at ten weeks and approximately 25% at both thirteen and sixteen weeks of age. Pericarditis was observed in 87% of the seven week challenge group, 28% in the ten week challenge group, 8% in the thirteen week challenge group and 4% in the sixteen week challenge group. All challenged groups showed a reduced average daily gain (ADG) compared to their age-matched non-challenged control groups. The largest disparity in ADG (1.2 lbs/day difference) was noted at thirteen weeks of age. Results of this study demonstrate that these animals were susceptible to MHR-associated lameness through sixteen weeks of age while susceptibility to MHR-associated polyserositis appeared to peak at seven weeks of age.

Serum Thymidine Kinase 1, Canine-C-Reactive Protein, Haptoglobin, and Vitamin D Concentrations in Dogs with Immune-Mediated Hemolytic Anemia, Thrombocytopenia, and Polyarthropathy.

BACKGROUND: Relapses of immune-mediated hemolytic anemia (IMHA), thrombocytopenia (ITP), or polyarthropathy (IMPA) occur despite normal hematologic and cytologic parameters. Thymidine kinase 1 (TK1), canine C-reactive protein (c-CRP), haptoglobin (HPT), and 25-Hydroxyvitamin-D (25(OH)D) might be adjunct to current monitoring strategies. HYPOTHESIS/OBJECTIVES: Compare serum concentrations of TK1, c-CRP, HPT, and 25(OH)D in dogs with well- and poorly controlled primary IMHA, ITP, or IMPA. ANIMALS: Thirty-eight client-owned dogs. METHODS: Prospective descriptive study. Dogs diagnosed with IMHA, ITP, or IMPA had serum biomarker concentrations measured commercially. Disease control was assessed by hematocrit/PCV and reticulocyte count, platelet count, and synovial fluid cytology for IMHA, ITP, and IMPA, respectively. Statistical analysis performed by Mann-Whitney rank-sum tests and receiver operating characteristic curves. RESULTS: TK1 and c-CRP, but not HPT significantly decreased with well- versus poorly controlled IMHA (P = 0.047, P = 0.028, P = 0.37). C-CRP, but not TK or HPT was significantly lower with well- versus poorly controlled IMPA (P = 0.05, P = 0.28, P = 0.84). Sensitivity and specificity of TK and c-CRP (simultaneously) for detecting dogs with poorly controlled IMHA were 88 and 100%, respectively. Sensitivity and specificity of c-CRP for detecting poorly controlled dogs with IMPA were 13 and 100%, respectively. 92% of dogs were vitamin D insufficient (<100 ng/mL) regardless of disease control. CONCLUSIONS AND CLINICAL IMPORTANCE: Combining TK1 and c-CRP might act markers of disease control in dogs with IMHA. Canine-CRP cannot be recommended as an independent marker of disease control in IMPA. 25(OH)D insufficiency in immune-mediated disorders might benefit from further study to determine if supplementation could improve therapeutic response or reduce disease risk.

Acute phase protein haptoglobin as inflammatory marker in serum and synovial fluid in an equine model of arthritis.

Acute phase proteins are useful inflammatory markers in horses. Haptoglobin (Hp) serum level is increased in horses undergoing different inflammatory processes, including arthritis. However, Hp concentration has not been assessed in inflammatory synovial fluid (SF). The aim of the present study was to investigate the Hp response in serum and SF in horses undergoing experimentally induced arthritis. For this purpose, serum and SF samples were collected from 12 animals before amphotericin B-induced arthritis was created (T0, healthy) and 15days after the lesion induction (T1, joint inflammation) and Hp was determined by single radial immunodiffusion. The Hp increase between T0 and T1 was significant in both serum and SF, and serum Hp concentration at T0 was significantly higher than in SF, but significant differences were not found at T1, indicating a higher Hp increase in SF. A significant positive correlation for Hp concentration between serum and SF samples was found. These results highlight the potential usefulness of Hp as inflammatory marker in horses, showing for the first time the increase of Hp in SF from joint inflammation in the horse.

Diversity of Escherichia coli strains involved in vertebral osteomyelitis and arthritis in broilers in Brazil.

BACKGROUND: Locomotor disorders and infections by Escherichia coli represent major concerns to the poultry industry worldwide. Avian pathogenic E. coli (APEC) is associated with extraintestinal infections leading to respiratory or systemic disease known as colibacillosis. The most common lesions seen in cases of colibacillosis are perihepatitis, airsacculitis, pericarditis, peritonitis/salpingitis and arthritis. These diseases are responsible for significant economic losses in the poultry industry worldwide. E. coli has been recently isolated from vertebral osteomyelitis cases in Brazil and there are no data on molecular and phenotypic characteristics of E. coli strains isolated from lesions in the locomotor system of broilers. This raised the question whether specific E. coli strains could be responsible for bone lesions in broilers. The aim of this study was to assess these characteristics of E. coli strains isolated from broilers presenting vertebral osteomyelitis and arthritis in Brazil. RESULTS: Fifteen E. coli strains from bone lesions were submitted to APEC diagnosis and setting of ECOR phylogenic group, O serogroup, flagella type, virulence genes content, genetic patterns by Pulsed Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST). In addition, bacterial isolates were further characterized through a lethality test, serum resistance test and antibiotic resistance profile. E. coli strains harbored different genetic pattern as assessed by PFGE, regardless of flock origin and lesion site. The strains belonged to seven sequence types (STs) previously described (ST117, ST101, ST131, ST 371 and ST3107) or newly described in this study (ST5766 and ST5856). ECOR group D (66.7 %) was the most frequently detected. The strains belonged to diverse serogroups (O88, O25, O12, and O45), some of worldwide importance. The antibiotic resistance profile confirmed strains' diversity and revealed a high proportion of multidrug-resistant strains (73 %), mainly to quinolones and beta-lactams, including third generation cephalosporin. The percentage of resistance to tetracycline was moderate (33 %) but always associated with multidrug resistance. CONCLUSIONS: Our results demonstrated that vertebral osteomyelitis and arthritis in broilers can be associated with highly diverse E. coli based on molecular and phenotypic characteristics. There was no specific virulence patterns of the E. coli strains associated with vertebral osteomyelitis or arthritis. Also, E. coli strains were frequently multidrug resistant and belonged to STs commonly shared by APEC and human ExPEC strains.

Cryptococcus neoformans var. grubii-Induced Arthritis with Encephalitic Dissemination in a Dog and Review of Published Literature.

This article describes the clinical, pathological, and immunohistochemical findings associated with Cryptococcus neoformans var. grubii in a 4-year-old female Boxer dog from Uberlândia, Minas Gerais, Southeastern Brazil. Clinically, there was a swelling at the right metatarsal region and the hock joint with enlargement of regional lymph nodes. Radiographical evaluation revealed lysis of the tarsal bone; cytology demonstrated cryptococcal intralesional organisms at the swollen joint. Despite empirical antifungals therapeutic, the animal developed neurological cryptococcosis and died spontaneously. Significant pathological alterations included arthritis, lymphadenitis, and encephalitic cryptococcomas associated with numerous intralesional narrow-necked budding encapsulated yeasts. Immunohistochemistry utilising monoclonal antibodies that label C. neoformans sp. complex capsule, characterised the yeasts as C. neoformans var. grubii. Collectively, the pathological and immunohistochemical findings of this dog indicate that the intralesional organisms observed within the articular surface of the hock joint, lymph nodes, and the brain were C. neoformans var. grubii, confirming the participation of this fungal pathogen in the development of cryptococcal arthritis. In this case, the most likely pathogenesis was percutaneous inoculation with resultant abscess-like lesion, which resulted in the draining sinus, swelling of the right hind limb with progression to the articular disease. Thereafter, the fungal pathogen probably compromised the adjacent lymph nodes with subsequent haematogenous distribution to the brain, terminating with cryptococcal arthritis, lymphadenitis, and encephalitis.

Comparative evaluation of therapeutic efficacy of sulfadiazine-trimethoprim, oxytetracycline, enrofloxacin and florfenicol on Staphylococcus aureus-induced arthritis in broilers.

Staphylococcus aureus is an important human and veterinary pathogen that causes economic loss in the poultry industry. This study aimed to compare therapeutic efficacy of 4 commonly used antibiotics in poultry on S. aureus-induced arthritis in broilers. Sixty broilers, 8 weeks of age, were assigned at random into 7 groups as follows: (1) negative control (n = 5); (2) vehicle control (n = 5); (3) sulfadiazine-trimethoprim, 250 ml/1000 l drinking water (n = 10); (4) oxytetracycline 20%, 1 mg/l drinking water (n = 10); (5) florfenicol 10%, 1/1000 v/v in drinking water (n = 10); (6) enrofloxacin 10%, 1/1000 v/v in drinking water (n = 10) and (7) positive control (n = 10). Birds in group 2 were injected with 1 ml of sterile TSB medium into the right tibiotarsal joint on d 0 while other birds (except group 1) were challenged with 1 ml of 1.2 × 10(10) CFU/ml suspension of S. aureus bacteria. Antibiotic therapy was started from d 4 post challenge and continued for 5 d. At the end, birds were weighed and clinical severity of arthritis was determined. After blood collection, birds were slaughtered and tibiotarsal and hip joints were evaluated grossly. The content of inflammatory exudates of tibiotarsal joint and the degree of femoral head necrosis were recorded. Mucin clot test and histopathological evaluation were performed on right tibiotarsal joint. Serum interleukin 6 was also assayed. Sulfadiazine-trimethoprim had higher therapeutic efficiency with regard to most of the assayed criteria, whereas none of the antibiotics significantly affected femoral head necrosis and body weight. These data will help clinicians to have better antibiotic choice in field conditions.

Analysis of lactate concentrations in canine synovial fluid.

OBJECTIVE: To report synovial fluid lactate concentrations in normal and pathological canine joints. STUDY DESIGN: Controlled, prospective study. METHODS: Lactate was measured in synovial fluid using a hand-held meter and the rest of the fluid was sent to a commercial laboratory for analysis. Samples were divided into four groups; group 1: control, group 2: osteoarthritis, group 3: immune-mediated inflammatory arthritis, and group 4: septic arthritis. Statistical analysis was performed to compare lactate concentrations between the four groups and to examine the predictive value of lactate in the diagnosis of septic arthritis. A correlation was sought between synovial fluid lactate and synovial fluid total nucleated cell count and total protein. RESULTS: Seventy-four samples were investigated from 55 dogs. Statistical analysis found that lactate concentrations were significantly higher in the septic arthritis group than in each of the other three groups. No significant correlation could be found between synovial fluid lactate concentrations and synovial fluid total nucleated cell count or synovial fluid total protein. Lactate concentration was found to be a useful predictor of septic arthritis, with a low concentration pointing towards exclusion rather than a high concentration to the diagnosis of septic arthritis. CLINICAL SIGNIFICANCE: Synovial fluid lactate concentration is not a good marker for osteoarthritis or immune-mediated inflammatory arthritis, but it is significantly increased in septic arthritis and could help the clinician in ruling out this condition in a quick and cost-effective way.

Molecular identification of Bartonella species in dogs with leishmaniosis (leishmania infantum) with or without cytological evidence of arthritis.

Recent evidence suggest that Bartonella species may cause polyarthritis and lameness in dogs. Canine leishmaniosis (CanL) due to Leishmania infantum is a multi-systemic disease often occurring in association with arthritis. We hypothesized that concurrent Bartonella infection may be a contributing factor for the development of arthritis in dogs with CanL. Hence the primary objective of this study was to investigate the molecular prevalence of Bartonella spp. in dogs with naturally occurring CanL, with or without cytologically documented arthritis. Thirty-eight dogs with CanL (31 with neutrophilic arthritis and 7 without arthritis) were retrospectively studied. Seventy-four archived clinical specimens from these 38 dogs, including 33 blood samples, 19 bone marrow (BM) samples and synovial fluid (SF) aspirates from 22 dogs were tested for Bartonella spp. DNA using the Bartonella alpha proteobacteria growth medium (BAPGM) diagnostic platform. Overall, eight (21.1%) dogs were infected with one or two Bartonella species; however, Bartonella spp. infection was not associated with arthritis in dogs with CanL. Further prospective studies are warranted to determine if there is a correlation between Bartonella spp. infection and the development of arthritis in dogs with CanL.

Bacteria and Toll-like receptor and cytokine mRNA expression profiles associated with canine arthritis.

The major forms of inflammatory canine arthritis are immune-mediated arthritis (IMA) and septic arthritis (SA), although some cases of cruciate disease (CD) are associated with significant levels of synovitis. In this study, the bacteria associated with canine arthritis were identified and mRNA expression levels of Toll-like receptors (TLRs) and pro-inflammatory cytokines determined. Of the 40 synovial fluid samples analysed, bacteria were isolated from 12 samples by culture (2 CD, 10 SA) and detected in 4 samples (3 CD, 1 SA) using culture-independent methods. Statistically significant increases in TLR2, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-12 mRNA expression were seen in all disease groups compared to normal controls. All disease groups had decreased mRNA expression of other TLRs compared to normal controls, but this did not reach statistical significance. Synovial fluid cell counts revealed that the highest number and proportion of mononuclear cells and neutrophils were found in the IMA and SA samples, respectively. Age had an effect on the TLR and cytokine mRNA expression profiles: TNF-α (p=0.043) and IL-12 (p=0.025) mRNA expression was increased and TLR4 mRNA expression was reduced (p=0.033) in dogs up to 4 years of age compared to older animals. In the 10 SA samples from which bacteria were isolated, statistically significant increases in TLR2, TLR7, TNF-α and IL-6 mRNA expression were observed. It is concluded that canine arthritis is associated with increased mRNA levels of pro-inflammatory cytokines, which could in some cases be mediated by bacteria through activation of TLR2.

The effect of antimicrobial treatment and preventive strategies on bovine respiratory disease and genetic relatedness and antimicrobial resistance of Mycoplasma bovis isolates in a western Canadian feedlot.

Feedlot calves (n = 3784) were systematically randomized and allocated in a 2 × 2 factorial study to receive metaphylactic oxytetracycline (OTC) on arrival or no antimicrobial, as well as florfenicol once subcutaneously or twice intramuscularly (48 h apart) if diagnosed with bovine respiratory disease (BRD). Calves of different treatment groups were comingled and followed from placement to re-implantation (~100 days). Animals receiving OTC had a reduced risk of BRD, an increased risk of arthritis, and no significant differences in average daily gain, BRD relapse, overall mortality, or BRD mortality. There were no significant differences between treatment protocols. Deep nasal swabs (n = 233) taken at arrival (n = 122), treatment (n = 77), and swabs from lungs and joints at postmortem (n = 34) were cultured for Mycoplasma bovis from 61 animals ill or dying of chronic pneumonia and arthritis and from 61 healthy calves. There was significant variation in diversity among isolates (n = 51) between study years and different cattle. Metaphylaxis or antimicrobial treatment did not affect the diversity of isolates. Except for tilmicosin, isolates were largely susceptible to tested antimicrobials.

Effet du traitement antimicrobien et des stratégies préventives sur le complexe respiratoire bovin ainsi que la relation génétique et l'antibiorésistance des isolats deMycoplasma bovisdans un parc d'engraissement de l'Ouest canadien. Les veaux d'un parc d'engraissement (n = 3784) ont été systématiquement randomisés et répartis dans une étude factorielle 2 × 2 pour recevoir de l'oxytétracycline métaphylactique (OTC) à l'arrivée ou pas d'antimicrobien, ainsi qu'une injection sous-cutanée ou deux injections intramusculaires (à intervalle de 48 h) de florfénicol s'ils étaient diagnostiqués avec le complexe respiratoire bovin (CRB). Les veaux de différents groupes de traitement ont été regroupés pêle-mêle et suivis du placement à la réimplantation (~100 jours). Les animaux recevant l'OTC avaient un risque réduit de CRB, un risque accru d'arthrite et ne présentaient pas de différences significatives pour le gain de poids quotidien moyen, la rechute du CRB, la mortalité globale ou la mortalité associée au CRB. Il n'y avait aucune différence significative entre les protocoles de traitement. Des écouvillonnages nasaux profonds (n = 233) prélevés à l'arrivée (n = 122), au traitement (n = 77) et des écouvillonnages des poumons et des articulations post mortem (n = 34) ont été cultivés pour Mycoplasma bovis à partir de 61 animaux malades ou mourants de pneumonie chronique et d'arthrite et de 61 veaux en santé. Il n'y avait aucune variation significative dans la diversité des isolats (n = 51) entre les années d'étude et les différents bovins. La métaphylaxie ou le traitement antimicrobien n'a pas affecté la diversité des isolats. Sauf pour la tilmicosine, les isolats étaient largement sensibles aux antimicrobiens testés.(Traduit par Isabelle Vallières).

Mycoplasma corogypsi-associated polyarthritis and tenosynovitis in black vultures (Coragyps atratus).

Three wild American black vultures (Coragyps atratus) were presented to rehabilitation centers with swelling of multiple joints, including elbows, stifles, hocks, and carpal joints, and of the gastrocnemius tendons. Cytological examination of the joint fluid exudate indicated heterophilic arthritis. Radiographic examination in 2 vultures demonstrated periarticular soft tissue swelling in both birds and irregular articular surfaces with subchondral bone erosion in both elbows in 1 bird. Prolonged antibiotic therapy administered in 2 birds did not improve the clinical signs. Necropsy and histological examination demonstrated a chronic lymphoplasmacytic arthritis involving multiple joints and gastrocnemius tenosynovitis. Articular lesions varied in severity and ranged from moderate synovitis and cartilage erosion and fibrillation to severe synovitis, diffuse cartilage ulceration, subchondral bone loss and/or sclerosis, pannus, synovial cysts, and epiphyseal osteomyelitis. No walled bacteria were observed or isolated from the joints. However, mycoplasmas polymerase chain reactions were positive in at least 1 affected joint from each bird. Mycoplasmas were isolated from joints of 1 vulture that did not receive antibiotic therapy. Sequencing of 16S rRNA gene amplicons from joint samples and the mycoplasma isolate identified Mycoplasma corogypsi in 2 vultures and was suggestive in the third vulture. Mycoplasma corogypsi identification was confirmed by sequencing the 16S-23S intergenic spacer region of mycoplasma isolates. This report provides further evidence that M. corogypsi is a likely cause of arthritis and tenosynovitis in American black vultures. Cases of arthritis and tenosynovitis in New World vultures should be investigated for presence of Mycoplasma spp, especially M. corogypsi.