A Serologic Variant of Mycoplasma Hyorhinis Recovered from the Conjunctiva of Swine

In an examination of conjunctival samples from 40 piglets for mycoplasmas, 17 isolates were obtained. Eight could be identified as Mycoplasma hyorhinis, three as Mycoplasma flocculare, and one as Acholenlasma sp. Five strains were not readily identifiable, but together with two previously recovered strains they were found to represent a distinct serogroup. All seven strains were glucose and phosphatase positive. Incubation in a CO₂-enriched atmosphere led to enhancement of the growth on solid medium. The serogroup was serologically related to M. hyorhinis, but not to a number of other glucose fermenting species of mycoplasma, and it may therefore be regarded as a new subspecies of M. hyorhinis.     

Colonisation pattern of the respiratory tract of calves by Mycoplasma dispar

Eight conventionally reared, 1- to 11-week old Ayrshire calves were naturally infected by a strain of Mycoplasma dispar (M. dispar). The colonisation was quantitatively followed by nasal swab samples, transtracheal aspiration samples and by the examination of the whole of the respiratory tract for mycoplasmas at slaughter after a follow-up period of 7–10 months.The fairly uniform pattern of the colonisation by M. dispar was revealed: A high degree of colonisation, measuring 10⁵–10⁸ colour change units (ccu) per nasal sample, lasted for a period of 2–5 months and was followed by a slow decrease in titres. Seven of the calves still harboured M. dispar in their respiratory tracts at slaughter. Intermittently obtained transtracheal aspiration samples were all positive for M. dispar and the titres were regularly higher than those for the simultaneously taken nasal samples indicating a high ability of M. dispar to continuously colonize the more distal parts of the respiratory tract. It was demonstrated that the sensitivity of nasal swabbing in the detection of M. dispar infection largely depended on the phase of colonisation : The method was good for the detection of a fairly recent infection of M. dispar, but inadequate for detection of low grade carriers.In various phases, the calves also became infected by Mycoplasma bovirhinis and Acholeplasma laidlawii. Their ability to colonize the whole respiratory tract was lower than that of M. dispar.     

Comparison of detection procedures of Mycoplasma hyopneumoniae, Mycoplasma hyosynoviae, and Mycoplasma hyorhinis in lungs, tonsils, and synovial fluid of slaughtered pigs and their distributions in Thailand

The aim of this study was to investigate whether direct PCR (DP) gave similar results to culture prior to PCR (CPP) for detecting mycoplasmas in different types of pig tissues. A total of 724 samples obtained from lungs, tonsils, or synovial fluids from 270 slaughtered pigs were used. The history of clinical signs, lung score, and the presence of joint lesions were recorded during sample collection. The rates of detection of Mycoplasma hyopneumoniae, Mycoplasma hyosynoviae, and Mycoplasma hyorhinis using both procedures were evaluated. The overall prevalences of M. hyopneumoniae, M. hyosynoviae, and M. hyorhinis were 40.3%, 12.3%, and 64.6%, respectively, and the detection rate depended on the sample type and the procedure used. With lung tissue, DP gave a higher detection rate for M. hyopneumoniae (77.4%) than CPP (38.5%). M. hyorhinis was detected by CPP at 15.6% and 18.1% and by DP at 31.5% and 5.2%, respectively. The positive rate derived from tonsil from CPP was closed to that of DP. Using synovial fluid could not yield any positive M. hyorhinis from CPP whereas 37.2% was positive from DP. In contrast, using sample tissue from lung and tonsil by CPP could show much higher positive number than that of DP. There was a significant relationship between joint lesion and M. hyorhinis detection by DP (P < 0.05) but not for M. hyosynoviae and M. hyorhinis detected by CPP. We speculated that lung was a proper sample for M. hyopneumoniae and M. hyorhinis detection by DP and CPP, respectively. Tonsil was likely the community of persistent M. hyosynoviae and M. hyorhinis with highly detection by CPP. Synovial fluid was apparently unsuitable for mycoplasmal culture. The accuracy of mycoplasmal detection may depend upon the type of sample relevant to the detection procedure used.     

Absence of strictly age-related resistance to Mycoplasma hyosynoviae infection in 6-week-old pigs

Mycoplasma hyosynoviae has never been reported to cause arthritis in pigs younger than 10 weeks of age. In order to investigate whether a strict age-related resistance exists, four 6-week-old pigs and four 13-week-old pigs, all immunologically na?ve with respect to M. hyosynoviae, were inoculated intranasally with the agent and autopsied at day 11 or 13 after infection. One uninoculated pig per age group was included as a negative control. Just as the 13-week-old pigs, the 6-week-old piglets were susceptible to blood, joint and tonsillar infection with M. hyosynoviae and developed clinical arthritis following inoculation with the agent. Thus, we found no evidence of an age-related resistance to the infection.     

Interactions of highly and low virulent Mycoplasma hyopneumoniae isolates with the respiratory tract of pigs

Mycoplasma hyopneumoniae is the etiological agent of swine enzootic pneumonia, a chronic nonfatal disease affecting pigs of all ages. To obtain better insight in the mechanisms responsible for differences in virulence between highly and low virulent M. hyopneumoniae isolates, 23 caesarean-derived, colostrum-deprived piglets were randomly assigned to three groups. Groups 1 and 2 consisted of nine animals each, which were intratracheally inoculated at 1 week of age with a highly or a low virulent isolate of M. hyopneumoniae, respectively. The remaining five animals were inoculated with sterile culture medium. Animals were euthanized at 5, 10, 15 and 28 days post-inoculation (DPI). Animals inoculated with the highly virulent isolate had more neutrophils in BAL fluid at 10, 15 and 28DPI compared to the other groups. At 10 and 15DPI, animals in the highly virulent group had significantly higher concentrations of TNF-alpha in BAL fluid. IL-1beta concentration in this group was higher at 5 and 28DPI compared to the other groups. From 10DPI onwards, significantly higher titres of M. hyopneumoniae were detected in the BAL fluid of animals inoculated with the highly virulent isolate compared to animals inoculated with the low virulent isolate. Additionally, the in vitro generation time of the highly virulent M. hyopneumoniae isolate was significantly shorter than that of the low virulent isolate. The present study indicates that the difference in pathogenicity between the highly and low virulent isolates is associated with a faster in vitro growth, a higher capacity to multiply in the lungs and the induction of a more severe inflammation process by the highly virulent isolate.     

Mycoplasma suipneumoniae and mycoplasma flocculare in the growth precipitation test.

A number of laboratory and field strains of Mycoplasma suipneumoniae and Mycoplasma flocculare were subjected to a comparative examination by the growth precipitation test. It was found that all the strains could readily be identified by that test. Slight evidence of cross-reaction was noted for a few of the laboratory strains, but not until late in the observation period. Only some of the field strains would form precipitates when primary cultures (from tissue suspensions) were used, but all strains could be identified already in the second and third passages. The test therefore seems well suited for distinguishing the two species from each other.     

Heterogeneity of Mycoplasma dispar.

Seventy bovine mycoplasma strains recovered from cases of calf pneumonia, and all displaying the cultural characteristics of Mycoplasma dispar, were compared to the type strain of this species by the disc growth inhibition test, the metabolism inhibition test and indirect epi-immunofluorescence test applied to colonies on agar. Sixty-seven strains were found to be identical with M. dispar. The remaining three strains formed a distinct serogroup partially separate from the type strain of M. dispar, but the difference from the type strain was not considered great enough to warrant the establishment of a subspecies.     

猪肺炎支原体和猪鼻支原体双重PCR检测方法的建立与应用

根据猪肺炎支原体(Mhp)和猪鼻支原体(Mhr)的16S rRNA基因设计3条引物, 建立Mhp和Mhr的双重PCR检测方法,并对该方法进行了特异性和敏感性试验,并使用建立的方法检测了临床样品和疫苗样品。结果显示该方法具有良好的特异性,最低可检测到0.66ng 的Mhp基因组DNA和0.58 ng Mhr基因组DNA,临床样品和疫苗样品检测结果与普通PCR检测结果一致。该双重PCR方法,可用于Mhp与Mhr的鉴别、诊断以及疫苗纯粹性检查,快速而准确。     

Experimental studies on the pathogenicity of Mycoplasma ovipneumoniae and Mycoplasma arginini for the respiratory tract of goats.

Mycoplasma ovipneumoniae and Mycoplasma arginini were the species of Mollicutes most commonly isolated from 175 goats with respiratory disease in Ontario. The pathogenicity of M. ovipneumoniae, strain B321B and M. arginini, strain D53e, was assessed in goats following endobronchial inoculation. One out of three two year old goats developed fever after inoculation with a pure culture of strain B321B, and it had extensive subacute fibrinous pleuritis when necropsied three weeks later. Neither of the remaining goats had lesions in the respiratory tract. Mycoplasma ovipneumoniae was recovered from one of the animals four days after inoculation, but not at necropsy from any of the goats, at which time a marked humoral immune response with growth inhibiting antibodies was detected. In a second experiment three four to five week old goats were inoculated with the same strain and three other goats were given placebo treatment. One experimental goat developed fever and coughing, and it had extensive subacute fibrinous pleuritis in the right side and pneumonia. Another goat had focal pneumonia in the left diaphragmatic lobe. Microscopically there was subacute hyperplastic suppurative bronchiolitis, atelectasis and nonsuppurative alveolitis. The infected animals did not clear the mycoplasma and not all of them produced antibodies. Mycoplasma arginini, strain D53e, did not induce lesions in any of four goat kids within 14 days after inoculation but did cause transient elevations in rectal temperature, circulating monocytes, circulating neutrophils and blood fibrinogen. Mycoplasma arginini was infective and immunogenic for all inoculated animals and showed a particular affinity for the tonsil. Thus, this study provides the first evidence that M. ovipneumoniae is pathogenic for goats causing pneumonia and pleuritis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of serology,bacteriological isolation and polymerase chain reaction for the detection of pigs carrying Actinobacillus pleuropneumoniae in the upper respiratory tract after experimental infection

Pigs, asymptomatically infected with Actinobacillus pleuropneumoniae in their upper respiratory tract, can transmit the infection. Detection of such animals is indispensable to prevent the intake of the disease in a herd. This study was conducted to evaluate bacteriology, polymerase chain reaction (PCR) and serology for the detection of subclinically infected pigs. Pigs were inoculated onto the tonsils with an A. pleuropneumoniae serotype 9 strain (n=12, group 1) or phosphate buffered saline solution (PBSS) (n=5, group 2). To prevent infection of the lungs, pigs of group 1 were treated three times with sodium ceftiofur as an aerosol. A third group (n=5) was inoculated intranasally with the same strain. All animals were euthanized 30 days post-inoculation (dpi). In pigs of group 1, clinical signs were not observed. A small lung lesion was found in only one pig and A. pleuropneumoniae was isolated from this lesion. The bacterium was not isolated from the lungs of animals that did not develop lung lesions. A. pleuropneumoniae was demonstrated in tonsils of 9/12 animals using bacteriological isolation, whereas it was demonstrated in mixed bacterial cultures from tonsils of all 12 animals by PCR. In non-infected animals (group 2), clinical signs were not observed and A. pleuropneumoniae was not demonstrated in any sample. All intranasally infected animals (group 3) developed disease signs and lung lesions. High antibody titers against ApxI, ApxII and heat-stable antigens were detected in animals that developed lung lesions. Antibody titers against these antigens were low or absent in all other pigs. It was concluded that pigs carrying A. pleuropneumoniae in the upper respiratory tract generally do not show measurable antibodies in serum. Therefore, sensitive methods for the detection of the etiological agent such as PCR are required to identify carrier animals, while serological methods are not suitable.     

The prevalence of Mycoplasma ovipneumoniae and Mycoplasma arginini in the respiratory tract of sheep

Abstract

Extract

In an initial study of mycoplasmas of the respiratory tract of New Zealand sheep a number of strains of mycoplasma were recovered and identified as either M. ovipneumoniae or M. arginini (Clarke et al., 1974 Clarke, J. K., Brown, V. G. and Alley, M. R. 1974. Isolation and identification of mycoplasmas from the respiratory tract of sheep in New Zealand. N.Z. vet. J., 22: 117–121. [Taylor &; Francis Online] , [Google Scholar]). Investigations in Australia have produced evidence that M. ovipneumoniae is associated with a proliferative interstitial pneumonia in Queensland sheep (Sullivan et al., 1973 Sullivan, N. D., St. George, T. D. and Horsfall, N. 1973. A proliferative interstitial pneumonia of sheep associated with mycoplasma infection. I. Natural history of the disease in a flock. Aust. vet. J., 49: 57–62.  [Google Scholar]) and for this reason the present survey was undertaken to investigate the prevalence of mycoplasmas in the respiratory tract of sheepin New Zealand.     

Examination of the upper and lower respiratory tract relevant to purchase.

The intent and extent of the respiratory tract examination relevant to purchase are dictated by numerous factors, including historical information, signs suggestive of respiratory tract abnormalities, intended use of the horse, and economic considerations. Following a thorough and systematic examination of the horse at rest, evaluation during and following exercise may be warranted. The physical examination should include evaluation of regional symmetry of the head, neck, and thorax; evaluation of nasal airflow and patency; palpation of the nasal septum, larynx, and trachea; examination for surgical scars; and auscultation and percussion. Special examination techniques, including endoscopy, stress evaluation, and radiography, may be indicated. Much has been learned about the URT in recent years, particularly regarding endoscopy of the region and the interpretation of endoscopic findings. The reader is referred to a generous list of references to gain further detailed information regarding the endoscopic diagnosis of other URT conditions.     

1株猪鼻支原体的分离鉴定及致病性

猪鼻支原体是猪场感染率极高的一种支原体,可引起多发性浆膜炎、关节炎等症状。目前尚未建立标准的猪鼻支原体发病模型,也缺乏标准强毒株。本研究从某猪场发病猪的关节液中分离得到一株支原体,通过PCR检测、菌落形态观察、菌体形态电镜分析、菌株MLST分型等方法对其进行了鉴定,确认其为猪鼻支原体。为评价菌株致病性,将该分离株接种1月龄自然分娩不吃初乳猪（SF-pCD猪）,试验猪在感染后出现关节肿胀、跛行等临床症状,日增重显著低于对照组,并出现部分死亡。剖检结果显示感染组出现胸膜炎、腹膜炎、心包炎及关节炎,肺部组织病理分析显示为间质增宽,无虾肉样病变。从发病猪的扁桃体、肺、心及关节积液中可再次分离到攻毒株。综上,本研究分离获得一株猪鼻支原体,人工感染猪后可出现典型的发病症状,猪鼻支原体发病模型的建立为致病机制及疫苗研究奠定了重要的基础。     

Diagnosis of upper respiratory tract diseases in the performance horse.

Wastage of performance horses because of respiratory dysfunction is common. Appropriate identification of the disease is paramount for treatment recommendations. Diagnostic modalities for upper respiratory tract dysfunction include a thorough physical examination, radiographic evaluation when appropriate, and upper respiratory tract endoscopy. Anatomical deviations or structural are easily identified during resting evaluation, while exercise testing is often necessary to assess thedynamic properties of the upper airway. Utilizing the many diagnostic tools available allows the clinician to make an accurate diagnosis and recommend appropriate treatment.     

Tritrichomonas foetus and Mycoplasma felis coinfection in the upper respiratory tract of a cat with chronic purulent nasal discharge

A 5‐year‐old indoor male neutered Siamese cat was presented with clinical signs of sneezing and chronic bilateral purulent nasal discharge. Multiple nasal cavity swabs were submitted for bacterial cultures, Mycoplasma felis‐DNA qPCR, and cytology. M felisqPCR was positive and cytomorphologic diagnosis was severe, acute, purulent, rhinitis with intralesional protozoal microorganisms consistent with a Trichomonas spp. Nested PCR (nPCR) confirmed the diagnosis of Tritrichomonas foetus. Systemic therapy with doxycycline for M felis and metronidazole for T foetus was started with remission of clinical signs within 2 weeks; however, symptoms relapsed shortly after therapy was discontinued. This study represents the first documented case of T foetus associated with chronic nasal discharge in a cat, which supports the hypothesis that T foetus can live in the nasal cavity. It is also the first reported case of M felis and T foetus coinfection, which indicates that with mycoplasmal feline upper respiratory tract infections, T foetus should be considered as a coinfecting agent.