Patho-bacteriological investigation of an outbreak of Mycoplasma bovis infection in calves - Emerging stealth assault.

Mycoplasma bovis (M. bovis) is an important bacterium, causing severe respiratory infection, and arthritis in dairy animals worldwide. This study is based on 50 suckling calves among which 15 showed respiratory distress, lameness and swollen joints and died later. M. bovis was isolated and identified from all dead (n = 15) and live (17.14%; 06 out of 35) calves on the basis of bacteriological examination. In morbid calves, the carpus and stifle joints were severely affected, while necropsy revealed multiple well-circumscribed calcified abscesses and caseous exudates in cranio-ventral and diaphragmatic lobes of lungs. Suppurative polyarthritis, fibrino-suppurative, teno-synovitis and otitis media were the common and striking lesion observed at postmortem examination. Histopathological examination revealed broncho-interstitial pneumonia and necrotic fibrino-purulent broncho-pneumonia in lungs. Similarly, synovial membranes and joints revealed presence of multiple foci of liquefactive necrosis surrounded by lymphocytes, plasma cells, macrophages and peripheral fibroplasia. In the bacteriological investigations, the characteristic fried egg colonies of M. bovis further confirmed this infection in all suspected cases. In conclusion, the current clinico-histo-pathological features are the depictive picture, and is the first report of M. bovis infection in calves in Pakistan.

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.

Are bacterial load and synovitis related in dogs with inflammatory stifle arthritis?

It has been proposed that small quantities of microbial material within synovial joints may act as a trigger for development of synovitis. We have previously identified an association between intra-articular bacteria and development of inflammatory stifle arthritis and cranial cruciate ligament rupture (CCLR) in dogs, and now wished to quantify bacterial load and markers of synovitis in dogs with and without stifle arthritis and CCLR. Joint tissues were collected from dogs with CCLR (n=51) and healthy dogs with normal stifles (n=9). Arthritis was assessed radiographically in CCLR dogs. Bacterial load was assessed using qPCR and broad-ranging 16S rRNA primers. qRT-PCR was used to estimate expression of the T lymphocyte antigen receptor (TCR Vß), CD3ɛ, tartrate-resistant acid phosphatase (TRAP), IL-4, IL-17, and TNF-α genes. Severity of synovitis was assessed histologically. Bacterial load was increased in arthritic stifles, when compared with healthy stifles. Histologic synovitis in arthritic stifles was mononuclear and was significantly correlated with bacterial load (1 of 2 primer sets) (S(R)=0.49, p<0.001). In arthritic stifles, expression of TRAP in synovium was increased relative to healthy stifles. Expression of pro-inflammatory genes was not correlated with bacterial load, histologic inflammation, or radiographic arthritis. Translocation of bacterial material to the canine stifle is related to the presence of joint inflammation. The lack of a strong positive correlation suggests that bacterial load is unlikely to be a primary pro-inflammatory factor. However, dysregulation of immune responses within synovial tissues may be dependent upon an environmental microbial trigger.

Remitting seronegative symmetrical synovitis with pitting edema associated with subcutaneous Streptobacillus moniliformis abscess.

We describe an 84-year-old woman who developed remitting seronegative symmetrical synovitis with pitting edema (RS3PE) associated with a subcutaneous abscess of the hand due to Streptobacillus moniliformis. Polyarthritis and edema were relieved after therapy with corticosteroids. We review the association of RS3PE to different rheumatologic, neoplastic, or infectious diseases.

The hemagglutination-positive phenotype of Mycoplasma synoviae induces experimental infectious synovitis in chickens more frequently than does the hemagglutination-negative phenotype.

Inoculation with hemagglutination-positive (HA+) cultures of Mycoplasma synoviae AAY-4 induced acute synovitis significantly more frequently (P = 0.001) in chicken tibiotarsal-tarsometatarsal joints than did inoculation with HA-negative (HA-) cultures derived from the same clone of AAY-4. Immunoblotting analyses showed that HA+ cultures abundantly expressed two phase-variable hemadherence-associated surface membrane proteins of 53 kDa and 48 to 50 kDa defined by monoclonal antibodies. HA- cultures lacked the 53-kDa proteins and synthesized truncated 27- to 30-kDa forms of the 48- to 50-kDa proteins. Inoculation of cyclosporin A (CsA) into infected joints significantly decreased the frequency of acute synovitis (P = 0.001). Moreover, repeated intra-articular inoculation of CsA (three doses of 1 mg at 2-day intervals) significantly reduced the local antibody response to M. synoviae in the joints treated with CsA.

Rheumatological lesions in individuals with human immunodeficiency virus infection.

One hundred and twenty-three patients with human immunodeficiency virus infection have been referred to rheumatologists at our hospitals between October 1985 and April 1989 because of musculoskeletal symptoms. Thirty-four homosexual men presented with acute, peripheral, non-erosive arthritis (mean number of four joints affected) with the knees being involved in 23. Other features developing concurrently with arthritis included psoriasis, keratoderma blenorrhagica, plantar fasciitis, urethritis, conjunctivitis and anterior uveitis. Four of five patients investigated were HLA-B27-positive; none of 15 patients tested had raised titres of rheumatoid or antinuclear factors. Various infections were associated with the onset of arthritis and two patients with a recent history of diarrhoea had serological evidence of yersinia infection. No micro-organisms were identified within the joint except for HIV itself. At the time of onset of arthritis four of these individuals had the acquired immunodeficiency syndrome (AIDS); 11 were not known to be HIV-positive before testing which was performed following referral for arthritis. Six patients have since developed AIDS and four have died. In 15 individuals, including those who progressed to AIDS, joint symptoms have been severe, persistent and poorly responsive to non-steroidal anti-inflammatory drugs. In only five patients has the arthritis been known to resolve. Synovitis has also been seen in two women: in one of these HIV infection was thought to have been acquired through intravenous drug abuse. Other rheumatic lesions included myalgia/myositis, non-inflammatory peripheral arthritis, spinal pain, soft tissue lesions, arthralgia or myalgia of unknown cause and infective lesions including septic arthritis and bony infection due to histoplasmosis and atypical mycobacterial infection. It appears likely that HIV infection is a risk factor for the development of seronegative arthritis and other rheumatic lesions.