Pneumonic Lung Lesions Research Articles

Characteristics of Mycoplasma hyopneumoniae Strain ES-2 Isolated From Chinese Native Black Pig Lungs.

Mycoplasma hyopneumoniae is the primary pathogen of swine enzootic pneumonia and causes great economic losses to the swine industry worldwide. In China, M. hyopneumoniae seriously hinders the healthy development of the native black pigs. To prevent and treat porcine respiratory disease caused by M. hyopneumoniae, the characteristics of M. hyopneumoniae strain ES-2 isolated from Chinese native black pig lungs with gross lesions at post-mortem were studied for the first time in this study. Strain ES-2 cell was round or oval cells and most sensitive to kanamycin. The diameters of most strain ES-2 cells ranged from 0.4 to 1.0 μm with maximum viability of 1010 CCU/ml. Experimental challenge of animals with strain ES-2 showed respiratory disease could be reproduced, with pneumonic lung lesions evident. Comparative genomics analysis identified that 2 genes are specific to pathogenic M. hyopneumoniae strains, which may be predicted to be a molecular marker. These findings suggest that the study on the characteristics of M. hyopneumoniae strain ES-2 will guide the rapid and accurate drug use in the clinic, and develop a theoretical foundation for accurately diagnosing and treating the infection caused by pathogenic M. hyopneumoniae.

Molecular characterization of Mannheimia haemolytica associated with ovine and caprine pneumonic lung lesions

This study investigated via polymerase chain reaction (PCR) three main serotypes (A1, A2, and A6) and nine virulence-associated genes in 71 ovine and caprine Mannheimia haemolytica isolates obtained from lungs (n = 349) with pneumonic lesions from a slaughterhouse in Iran. The lung specimens were collected from sheep (n = 197) and goats (n = 152) between December 2018 and January 2020. A total of 71 M. haemolytica isolates were identified in sheep (37/197; 18.8%) and goat (34/152; 22.4%) pneumonic lungs. Serotypes A2 (30/71; 42.3%) and A6 (29/71; 40.9%) were the most frequently detected, whereas the A1 serotype was detected with a frequency of less than 10% (7/71; 9.9%) and five isolates remained unknown. The virulence genes lkt, pomA, and nanH were present in all the isolates. The detection rates for the remaining virulence-associated genes were: gcp (95.8%), lpsA (93%), fhaC (90%), irp (70.4%), hf (57.7%), and sodC (21%). The sodC gene was exclusively detected among A2 isolates (50%), while the irp gene was more prevalent among A2 isolates and the hf gene among A1 and A6 isolates. These data may be useful for the typing of isolates in epidemiological studies. This study provides information about the main serotypes and the prevalence of virulence-associated genes among M. haemolytica ovine and caprine isolates in Iran.

Field study on the safety and efficacy of intradermal versus intramuscular vaccination against Mycoplasma hyopneumoniae

The present study compares the safety and efficacy of a needle-free, intradermal Mycoplasma hyopneumoniae vaccine to an intramuscular one. 420 piglets (21+3 days of age) were randomly assigned to two...

A simplified evaluation system of surface-related lung lesions of pigs for official meat inspection under industrial slaughter conditions in Germany.

BackgroundEuropean and national administrative legislation require objective evaluation systems for organ lesions at pig slaughter. These results can be used as basis for herd health improvement programs by farmers and their consulting veterinarians. Various studies have shown that the current evaluation and recording of lesions by authorized meat inspectors are not reliable and produce significant inter-rater disagreement especially for lung lesions in pigs. The objectives of this study were to increase the usability of official meat inspection data by a developed and validated scheme and to analyze potential improvements in the reliability of the proposed system under industrialized slaughter conditions.ResultsA simplified evaluation scheme for surface-related lung lesions was developed based on morphometric evaluations of unaffected lungs with quantitative relationships of each lobe to the whole lung (“Rule of Tens”). Furthermore, a theoretical as well as a hands-on training program for meat inspectors was developed and applied. Based on 5,183 lungs, the authors established a baseline of the inter-rater reliability of current routine assessments of lung lesions as documented by meat inspectors compared with the assessments of an independent veterinarian using the developed simplified evaluation scheme. Most frequent inter-rater disagreements greater than 75% were found for moderate pneumonia. Sources of the deviations most frequently included misinterpretations of technical artifacts, which were erroneously assessed by the meat inspectors as pneumonic lung lesions. Results of the post-training investigation based on 4,646 lungs showed a significantly improved reliability of lung lesion evaluation and the inter-rater agreement increased in all respects. Especially the disagreement of recording moderate cases of pneumonia decreased in total to 15% deviations from reference.ConclusionsThe presented simplified lung evaluation scheme showed its capability to standardize the evaluation of lung lesions according to administrative legislation under industrialial slaughter conditions. The reliability of official meat inspections can be significantly increased with the help of the presented scheme to assess surface-related lung lesions of slaughter pigs. Continuous standardization and optimization can be achieved by personalized training programs in the framework of quality assurance systems for meat inspectors.

Mycoplasma bovis infection in respiratory disease of dairy calves less than one month old

Mycoplasma bovis is an important cause of bovine respiratory disease, especially in young calves where it can also cause arthritis, tenosynovitis and otitis. During 2009 and 2010 a survey was carried out on carcasses of calves less than one month old sent to the Diagnostic Laboratory of the Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna in Brescia, regardless of the presence of lung lesions, to detect this pathogen. PCR tests for Mycoplasma spp. and M. bovis were applied. 83 out of 224 (37%) lung tissue samples examined were positive at PCR test for Mycoplasma spp.; in 64 cases of these we observed typical respiratory lesions (P<0.001). M. bovis was identified in 26 out of 83 (31%) lung tissue samples positive at PCR test for Mycoplasma spp.; in 24 cases of these we observed typical respiratory lesions (P=0.039). Our data demonstrate that presence of Mycoplasma spp. and M. bovis positively correlates with pneumonic lung lesions in young dairy calves.

Clinicopathological evaluation of intranasal, subcutaneous and intramuscular routes of vaccination against intratracheal challenge of Peste des petits ruminants virus in goats

An experiment was conducted to compare the efficacy of intranasal vaccination against caprine Peste des petits ruminant lineage 1 variant virus infection with intramuscular and subcutaneous vaccinations. Twenty four goats were divided into four equal groups. Group 1 was vaccinated intranasally, group 2 was vaccinated subcutaneously, and group 3 intramuscularly, while group 4 was the unvaccinated control. In each group, the vaccinations were carried out once. All goats were challenged intratracheally with PPR virus at a concentration of 106.5 TCID50 two weeks after vaccination and were euthanised 21 days after the challenge. The clinical, lung consolidation, gross and histopathological scores were employed using standard techniques. All data were analysed statistically using the paired t-test and one-way analysis of variance (ANOVA). Group 3 had the highest clinical score following the challenge of vaccinated group while deaths were observed only in group 4. Three goats in group 2 and 3 had pneumonic lung lesions, compared with none in group 1 and all the goats in group 4. The lung lesions in group 4 were significantly (P<0.05) severe than in others. Similarly, the lesions in group 2 and 3 were less severe with the right lung more affected (P>0.05) while group 1 had no consolidation. This study showed that PPR vaccination using subcutaneous, intramuscular and intranasal routes were protective but that of intranasal was found to be easy to apply hence it could be used for the prevention of the disease in small ruminants.

Experimental Actinobacillus pleuropneumoniae challenge in swine: Comparison of computed tomographic and radiographic findings during disease

BackgroundIn pigs, diseases of the respiratory tract like pleuropneumonia due to Actinobacillus pleuropneumoniae (App) infection have led to high economic losses for decades. Further research on disease pathogenesis, pathogen-host-interactions and new prophylactic and therapeutic approaches are needed. In most studies, a large number of experimental animals are required to assess lung alterations at different stages of the disease. In order to reduce the required number of animals but nevertheless gather information on the nature and extent of lung alterations in living pigs, a computed tomographic scoring system for quantifying gross pathological findings was developed. In this study, five healthy pigs served as control animals while 24 pigs were infected with App, the causative agent of pleuropneumonia in pigs, in an established model for respiratory tract disease.ResultsComputed tomographic (CT) findings during the course of App challenge were verified by radiological imaging, clinical, serological, gross pathology and histological examinations. Findings from clinical examinations and both CT and radiological imaging, were recorded on day 7 and day 21 after challenge. Clinical signs after experimental App challenge were indicative of acute to chronic disease. Lung CT findings of infected pigs comprised ground-glass opacities and consolidation. On day 7 and 21 the clinical scores significantly correlated with the scores of both imaging techniques. At day 21, significant correlations were found between clinical scores, CT scores and lung lesion scores. In 19 out of 22 challenged pigs the determined disease grades (not affected, slightly affected, moderately affected, severely affected) from CT and gross pathological examination were in accordance. Disease classification by radiography and gross pathology agreed in 11 out of 24 pigs.ConclusionsHigh-resolution, high-contrast CT examination with no overlapping of organs is superior to radiography in the assessment of pneumonic lung lesions after App challenge. The new CT scoring system allows for quantification of gross pathological lung alterations in living pigs. However, computed tomographic findings are not informative of the etiology of respiratory disease.

도축돈에 대한 호흡기 질병의 병리학적 조사

The aims of this study were to assess the lung lesions and to compare gross observations with histopathological findings in the lungs of slaughter pigs. During August of 2010 through July of 2011, the 1,200 lung samples were randomly collected from slaughtered pigs in Korea. We examined prevalence of lung lesions and classified the lung lesion according to the severity of lung lesions. For the comparison of gross lesions with histopathological findings, BALT hyperplasia was also examined. Among the tested samples, 1,100 (91.7%) had pneumonic lung lesions. In the seasonal prevalence of pneumonic lung lesions, spring was the highest followed by winter, summer and autumn, respectively. The mean pneumonic score (<TEX>$mean{\pm}SD$</TEX>) was <TEX>$21.37{\pm}17.87$</TEX> and the highest gross lesion according to stages was 11~20% (27.2%, 326/1,200). The prevalence of pleuritis was 7.0% and the highest prevalence was determined in summer. In severity, the lungs collected in this study were frequently in chronic stage (36.4%, 437/1,200), and it was shown that BALT hyperplasia was more extensive in chronic lesion. In this study, the prevalence of pneumonic lung lesions showed a high side and appeared particularly high in the spring. Severity of lung lesion was the most prevalent chronic lesions which were consistent with histopathologic findings.

돼지 폐렴병소에서 분리한 Pasteurella multocida의 특성 및 항생제 감수성 양상

The present study was conducted to investigate the species-specific gene detection and antimicrobial susceptibility of Pasteurella (P.) multocida isolated from pneumonic lung lesions of Youngnam swine herds during the period from July 2006 to September 2007. A total of 91 (36.3%) strains of P. multocida were isolated from 251 pneumonic lung lesions. The species-specific P. multocida gene was detected at 460 bp amplicons by PCR. The P. multocida tested was susceptible to florofenicol (93.4％), amikacin (91.2％), cephalothin (87.9％), cefoxitin (84.6％), ofloxacin (80.2％) and norfloxacin (65.9％) in 27 antimicrobial susceptibility tests. Most of strains were resistant to more than 5 drugs.

Oral vaccination against mycoplasmal pneumonia of swine using a live Erysipelothrix rhusiopathiae vaccine strain as a vector

Erysipelothrix rhusiopathiae Koganei 65-0.15 strain, the live swine erysipelas vaccine for subcutaneous injection, has been shown to colonize the tonsils of pigs after oral inoculation. We thus evaluated the possible use of the strain as a vector for oral vaccination against mycoplasmal pneumonia of swine. Recombinant E. rhusiopathiae strains expressing the C-terminal domain of the P97 adhesin of Mycoplasma hyopneumoniae were constructed and examined for vaccine efficacy in mice and pigs. Mice subcutaneously inoculated with the recombinant strains were protected from challenge exposure to a virulent E. rhusiopathiae. Administration of milk replacer containing recombinant E. rhusiopathiae expressing the M. hyopneumoniae protein protected pigs from death after exposure to E. rhusiopathiae and significantly reduced the severity of pneumonic lung lesions caused by infection with M. hyopneumoniae.

Effect of vaccinating lambs against pneumonic pasteurellosis under New Zealand field conditions on their weight gain and pneumonic lung lesions at slaughter

In a field trial, 9174 lambs from seven commercial sheep flocks with a history of subclinical pneumonia were either vaccinated with Ovipast Plus (Intervet) or given a placebo by systematic...

A field trial to study the efficacy of respisure one® vaccine against pigs mycoplasmal pneumonia

The immunoprophylaxis of mycoplasmal pneumonia in swine (MPS) caused by Mycoplasma hyopneumoniae was investigated. A field trial was conducted on three commercial pig farms located in different parts of Lithuania. A Mycoplasma hyopneumoniae single dose Respisure One® vaccine was tested in 600 pigs for its effects on daily weight gain (DWG), lung lesions and meat quality. The other group of 600 piglets was left unvaccinated as a control. The evaluation of DWG from the time of vaccination until slaughter showed that the DWG in the vaccinated group increased by 5.5% (p<0.05). Vaccination against Mycoplasma hyopneumoniae decreased significantly (p<0.001) pneumonic lung lesions in vaccinated pigs. In this study, we examined the effects of vaccination against Mycoplasma hyopneumoniae on carcass quality, chemical composition, technological, culinary and physical properties of musculus longissimus dorsi. Our data showed that meat lightness L*(p<0.05), drip loss (p<0.001), fat thickness between 6-7 thoracic vertebrae were significantly higher (p<0.05), than in the unvaccinated pigs. We concluded that Respisure One® vaccine has positive effects daily weight gain, as well as on various carcass and meat quality parameters, at the same time minimizing lung lesions characteristic for mycoplasmal pneumonia.

The comparative pathogenicity of strains of eight serovars and untypable strains of Mannheimia haemolytica in experimental pneumonia of sheep

The experimental induction of pneumonic pasteurellosis in groups of conventionally reared lambs by 8 serovars (A1, A2, A6, A7, A8, A9, T10, and A11) and untypable (UT) strains of Mannheimia haemolytica (Mh) were examined and compared. The groups of lambs were inoculated intratracheally with 1.4 x 10(8) +/- 0.6 x 10(8) (mean +/- SD) colony-forming units of the Mh serovars or UT isolates in the 6-hour log phase of growth. The variables measured as indicators of disease severity were clinical score, percentage lung consolidation and microbiological re-isolation. The clinical parameters for each group were computed daily for 6 days post infection and the lambs which died were necropsied while the remaining lambs were killed on day 7 pi and the extent of lung consolidation was measured. Clinically, the mean scores for the M. haemolytica serovars were A1 (6.1), A2 (18.8), A6 (0.5), A7 (17.4) and A9 (8.5). The mean percent lung lesion scores for M. haemolytica serovars were A1 (12.5), A2 (66.3), A6 (5.0), A7 (51.3), A9 (33.8) and A11 (2.5). The percent mean pneumonic lung lesions recorded for groups inoculated with A2, A7 and A9 were significantly (P < 0.05) higher than the extent of lung lesions in the other groups. A statistically significant correlation was observed between clinical scores and the severity of the lung lesions (r = 0.96, P < 0.01). High titres of M. haemolytica were recovered from lung lesions, with 10 to 100 times the number of organisms inoculated being present in the lung lesions of lambs inoculated with serovars A2 and A7. These data indicate that although M. haemolytica serovars A1, A2, A6, A7, A9 and A11 are important primary lung pathogens of lambs, serovars A2, A7, and A9 are to be regarded as highly virulent strains that have a greater predilection than the other serovars for causing pneumonia in lambs.

Vaccine efficacy of the attenuated Erysipelothrix rhusiopathiae YS-19 expressing a recombinant protein of Mycoplasma hyopneumoniae P97 adhesin against mycoplasmal pneumonia of swine

The attenuated Erysipelothrix rhusiopathiae YS-19 strain was constructed for the purpose of delivering the C-terminal portion of the Mycoplasma hyopneumoniae P97 adhesin to the mucosal surface of the respiratory tract of pigs. In this study, the efficacy of the YS-19 vaccine against mycoplasmal pneumonia of swine was evaluated. Animal experiments revealed that intranasal immunization of pigs with the YS-19 strain significantly reduced the severity of pneumonic lung lesions caused by M. hyopneumoniae infection. In YS-19-immunized pigs, P97-specific serum antibodies were not detected. However, when stimulated with the P97 protein, peripheral blood mononuclear cells from the YS-19-immunized pigs had a significantly higher stimulation index ( P<0.05) than that of cells from control pigs at 7 days post-challenge.

Interaction of cattle health/immunity and nutrition.

The usual means of assessing the health of newly received beef cattle susceptible to bovine respiratory disease (BRD) are subjective, typically involving visual evaluation aided by minimal clinical measurements. Recent evidence based on the occurrence of pneumonic lung lesions at slaughter indicates a need for more accurate methods of diagnosing BRD. Inadequate passive immune transfer at birth may be an important risk factor in susceptibility to BRD, suggesting the need for management to improve passive transfer success rates. Preweaning management and vaccination practices offer opportunities for beef cattle producers to improve the immune status of newly weaned calves and decrease postweaning BRD. Feeding diets with higher levels of concentrate typically improves performance by newly weaned or received cattle, as does feeding diets supplemented with protein; however, limited data suggest that increasing concentrate and protein in receiving diets increases the rate and severity of subjectively determined BRD morbidity. Research with receiving diet concentrate/protein level relative to humoral and cell-mediated immune function coupled with indicators of health and performance is needed. Supplemental B vitamins are sometimes useful in receiving diets, but the effects have been variable, presumably reflecting differences in stress and associated feed intake responses. Vitamin E added to receiving diets to supply > or = 400 IU/animal daily seems beneficial for increasing gain and decreasing BRD morbidity; however, further dose titration experiments are needed. Supplemental Zn, Cu, Se, and Cr can alter immune function of newly received calves, and some field trials have shown decreases in BRD morbidity rate with supplementation; however, several experiments have shown no performance or health/immune benefits from supplementation of these trace minerals. Formulation of receiving diets should take into account decreased feed intake by highly stressed, newly received beef cattle and known nutrient deficiencies, but fortification of such diets with trace minerals beyond the levels needed to compensate for these effects is difficult to justify from present data.

Efficacy of intranasal administration of formalin-killed Pasteurella haemolytica A2 against intratracheal challenge in goats

A trial was conducted to compare the efficacy of intranasal vaccination in protecting goats against pneumonic pasteurellosis with intramuscular vaccination using an oil adjuvant vaccine, and a combination of the...

&lt;I&gt;Actinobacillus pleuropneumoniae&lt;/I&gt;1 型の新生豚感染

Suckling piglets delivered from sows that had complement-fixing antibody titers of 1: 32 againstA. pleuropneumoniaeserotype 1 were infected with this organism at as early as 10-day-old. Maternal antibody gradually declined and was not demonstrated hereafter 40-day-old, and pneumonic lung lesions were first detected in a piglet sacrificed at 46-day-old. From the results obtained here it was suggested that piglets were infected with A. pleuropneumoniae from their carrier sows at the early stage of suckling but the onset of illness might be delayed until maternal antibody disappeared.

Tylosin tartrate and tiamutilin effects on experimental piglet pneumonia induced with pneumonic pig lung homogenate containing mycoplasmas, bacteria and viruses

The effects of tylosin tartrate and tiamutilin were examined in pneumonias induced experimentally in neonatal piglets with a homogenate of pneumonic pig lung, obtained from pigs with naturally acquired enzootic pneumonia. The homogenate contained mycoplasmas, including Mycoplasma hyopneumoniae (M suipneumoniae) and M hyorhinis, and certain bacteria and viruses. The experimental pneumonias generally resembled mycoplasmal pneumonia histologically but were complicated by aspiration pneumonia in some animals. both tylosin tartrate (50 mg/kg) and tiamutilin (10 mg/kg) administered orally twice daily for 10 days, beginning 14 days after intranasal infection, significantly reduced the incidence and severity of macroscopical pneumonic lung lesions. M hyopneumoniae could be isolated from the lungs of the unmedicated piglets, but not from drug-treated piglets. The numbers of M hyorhinis, Acholeplasma granularum, Haemophilus parasuis, Pasteurella multocida and P haemolytica in the lung tissue of the infected piglets were significantly reduced by drug therapy. The role of bacterial in the experimental infection appeared to be that of secondary invaders.