Catarrhal Pneumonia Research Articles

Features of pathomorphological manifestation of low pathogenic influenza in laying hens

Relevance. In the available literature, there are enough works devoted to the study of pathomorphological changes in low pathogenic influenza. The described changes are not sufficiently systematized, including in laying hens.Methods. The material for the research was the corpses of 60 laying hens, 235–428 days old, egg crosses “Tetra”, “Hisex Brown”, “Dekalb White”, killed for diagnostic purposes. Research methods: autopsy, histological examination.Results. Leading macroscopic changes: cyanosis of the comb and earrings; acute serous-catarrhal rhinitis, laryngotracheitis; acute fibrinous-purulent sinusitis; acute catarrhal or fibrinous-hemorrhagic pneumonia, pulmonary edema; yolk peritonitis; granular and fatty degeneration, acute venous hyperemia of the liver, kidneys and myocardium; hemorrhages in the epicardium. The most characteristic histological changes: necrosis and desquamation of the integumentary epithelium of the larynx and trachea, inflammatory hyperemia, fibrinoid swelling of the walls of the vessels of microvasculature, hemorrhages, serous edema, pronounced lymphoid-macrophage and plasma cell infiltration of the mucous membrane; croupous pneumonia with a pronounced hemorrhagic accent, lymphoid-macrophage infiltration of the mucous membrane of the bronchi and parabronchi of the lungs, fibrinoid swelling of the walls of the vessels of microvasculature, hemorrhages, emphysema; hemorrhages in the serous membrane of the esophagus, in the mucous membrane of the duodenum, jejunum, ileum and caecum; acute venous hyperemia, serous edema, granular, smalland large-drop fatty degeneration of hepatocytes of the liver, fibrinoid swelling of the walls of the vessels of microvasculature, hemorrhages; acute venous hyperemia of the kidneys, serous edema, large-drop fatty and vacuolar degeneration of the epithelium of the urinary tubules, fibrinoid swelling of the walls of the vessels of microvasculature, hemorrhages; acute alterative myocarditis; fibrinoid swelling of the walls of the vessels of microvasculature of the spleen, hemorrhages; acute venous hyperemia of cerebral vessels, pronounced perivascular and pericellular edema.

Trigger role of infectious agents in the genesis of sudden infant death

Purpose. To increase the effectiveness of diagnostic predictors for the development of sudden infant death based on the study of the role of infectious agents.Materials and methods. A retrospective analysis of 120 cases of development of children, suddenly deceased, medical charts of pregnant women, histories of childbirth of mothers was carried out, and the morphological features of the suddenly deceased children were studied. The frequency of distribution and types of viruses detected using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction test (PCR) in the examined children who died suddenly in their first year of life were analyzed. Statistical analysis of the research results was made in the MedStat software.Results. The frequency of detection of various infectious agents among the deceased from sudden infant death is (64.4 ± 4.2) %. Morphohistological study indicated characteristic signs of catarrhal tracheobronchitis (83.0 ± 5.5) %, focal intraepithelial inflammation of the larynx and trachea (48.9 ± 7.3) %, desquamative catarrhal pneumonia (31.9 ± 6.8) %, as well as acute focal bronchitis (27.7 ± 6.5) %.Conclusion. The performed study confirms that in the genesis of sudden infant death, along with a role of social and economic, medical and biological factors, there is an obvious negative effect of infectious agents, with the infectious activator working as the trigger and provoking sudden infant death.

Production Significance of Bovine Respiratory Disease Lesions in Slaughtered Beef Cattle.

Simple SummaryRespiratory diseases are a common health and economic problem in beef cattle production. Bovine respiratory syndrome, by which these processes are known, needs to be studied in different aspects. Therefore, this study has tried to understand the impact on the production of this disease through the study of the post-mortem lesions observed in clinically healthy beef animals and its associated factors for the management system, age and gender. It was found that there is a high percentage of subclinical pneumonia, both chronic and acute fibrinous, with different grade expanse. The animals that showed lesions experienced a lower average carcass weight than those without lesions. Furthermore, the mixed and extensive production system, as well as young animals, are associated with a greater probability of presenting pneumonic lesions. The bacterial agents were only identified in the acute fibrinous pneumonia. This study reflects the high prevalence of animals arriving at the slaughterhouse that suffer or have suffered respiratory disease and can serve as herd monitoring to adopt the necessary health measures to avoid economic losses.Bovine respiratory disease (BRD) is still a serious concern in feedlots, where it exerts a negative effect on farm productivity. There is a shortage of studies focused on the evaluation of BRD-associated lesions at the slaughterhouse in clinically healthy animals. The objective of this work was to investigate the prevalence and type of subclinical pneumonic lesions in slaughtered beef cattle, according to the age range and management system, and its impact on carcass weight. A total of 1101 beef cattle intended for human consumption were examined at slaughter. Information on age, sex, management system and carcass weight was recorded. The presence and type of pneumonia were evaluated according to gross and microscopic findings and etiological agents by PCR. Lung pneumonic lesions appeared in 17.9% of animals and were predominant among veal calves. According to the type, chronic catarrhal pneumonia prevailed in the majority of animals, and mixed and extensively reared cattle were more likely to suffer acute fibrinous pneumonia. The presence of pneumonic lesions was associated with a significant decrease in carcass weight that had more of an impact in veal male calves coming from intensive systems. Bacterial infections were the predominant infectious agent and the only cause of acute fibrinous pneumonia, while viruses were infrequent and only found in lesions with chronic catarrhal pneumonia. This study shows the importance of BRD in beef feedlots upon production values and points out the feasibility of slaughterhouse assessment of pneumonia as a method for the evaluation of BRD significance.

Pathological description of naturally occurring Mycoplasma bovis associated pneumonia in bovine calves

Mycoplasma bovis is an important etiologic agent of bovine respiratory infection and predominantly causing chronic pneumonic lesion. The present study encompassed standardized pathological, immunohistological and molecular technique for diagnosing natural bovine pneumonic cases with Mycoplasma bovis associated lesions. During the study, examination of 87 carcasses putatively died of pneumonia where Mycoplasma bovis was ascertained in two bovine female calves by immunohistological staining and Polymerase chain reaction. The specific pathological lesions were noted as chronic bronchopneumonia with mild to moderate caseonecrotic lesion and suppurative bronchopneumonia typical of Pasteurella infection. The other bacterial organism associated with these cases was found to be of Pasteurella multocida detected on isolation. No viral etiological association was detected in immunohistological examination in respect of bovine parainfluenza type 3, bovine respiratory syncytial virus and infectious bovine rhinotracheitis virus. The result also revealed that M bovis infection may develop into a severe necrosuppurative bronchopneumonia when associated with high numbers of intralesional organism and into mild catarrhal bronchointerstitial pneumonia when associated with low numbers of organism.

Етіологія ензоотичної пневмонії свиней та стратегії боротьби з нею в фермерських господарствах Запорізької та Полтавської областей

Porcine enzootic pneumonia is a multifactorial disease, it leads to large and significant economic losses in pig farms and it remains a relevant veterinary problem. The involvement of new etiological agents in the association of pathogens and the constantly changing conditions on the farms lead to the fact that previously developed control schemes and methods of disease lost their effectiveness. Therefore, the identification of all the infectious agents that make up the association, as well as the concomitant factors that led to the occurrence of the disease in each case is the only correct way to control measures. When we studied the situation in pig farms in the south and in the central region of Ukraine, we found that mycoplasmas were the main etiological agent for Porcine enzootic pneumonia. We noted that mycoplasmosis as a monoinfection was recorded only in 9-12 % of cases. In most outbreaks Mycoplasmas were only members of associations along with Porcine reproductive and respiratory syndrome infection (6%), Type 2 Circovirus infection (6%), enterbacterias (19%) and pasterellas (59%). The course of the disease was also aggravated by the stress of early weaning of piglets and violations of the conditions of feeding and animal welfare. The most difficult enzootic pneumonia occurred in those farms where mycoplasmosis and pasteurellosis were exacerbated by the presence of pathogens of actinobacillus pleuropneumonia. In such farms the average daily weight gain decreased in piglets by a third and feed consumption increased to 28 %. Piglets on affected farms were ill with obvious respiratory clinical signs. And 82% of dead or killed piglets had signs of fibrinous pleuropneumonia or catarrhal pneumonia. In those farms where we recorded associated respiratory infections, we also found reproductive-neonatal infections of pigs. In such farms treatment and prophylactic measures using traditional antimicrobial special remedies and monovaccines, did not give the expected effect. We proposed the use of autovaccines for associated enzootic pneumonia.

Вплив умовно патогенної мікрофлори на розвиток патологічного процесу за пастерельозно-аскаридіозного мікст захворювання птиці

The article presents the results of autopsy dead of poultry and bacteriological studies of pathological material confiscation of dead birds. It was established that the pathological process at the mixed pasteurellosis and ascaridosis diseases is enhanced by the complications its conditioned pathogenic microflora, ie Escherichia coli, which amounts to 85.4% of all the isolated microorganisms. In most cases the selection of conditionally pathogenic microflora in the mixed pasteurellosis and ascaridosis disease observed in the spring to 82.4%. Pathological changes at he mixed pasteurellosis and ascaridosis disease complicated by conditionally pathogenic microflora were atypical: exhaustion, conjunctivitis, allocation from the nose muddy mucus hydropericarditis, catarrhal pneumonia, perihepatitis, splenitis, catarrhal hemorrhagic enterocolitis, hemorrhagic duodenitis, ruffled feathers, near the cloaca soiled dark gray of the droppings, sometimes mixed with fibrin, are thickened joints, in articular vagina accumulation of exudate straw-yellow color. Sometimes at roosters observed cyanosis of the comb, turkeys – cyanotic head skin, pigeons and parrots – expressed exhaustion, enlargement of the spleen twice from the physiological norm. In most cases were isolated conditionally pathogenic microflora of parenchymal organs: heart, liver, spleen and bone pulp. Because isolated pathogens play an important role in the development and aggravation of the pathological process at he mixed pasteurellosis and ascaridosis disease of poultry.

ОСОБЛИВОСТІ ПАТОМОРФОЛОГІЧНИХ ЗМІН ЗА АСОЦІАТИВНОГО ПЕРЕБІГУ МІКОПЛАЗМОЗУ

Coplasma pneumonia of pigs is a chronic infectious disease of pigs of all age groups, characterized by exudative–proliferative inflammation of the lungs, intermittent fever, cough and delayed growth and development of piglets, and complications – progressive weight loss. Mycoplasmosis increases the susceptibility of pigs to secondary infections, making it more difficult and often leads to death of animals.Conducted a comprehensive laboratory study of the use of bacteriological, serological and coprologic research methods pigs aged 1.5 and 3 months. The studies were conducted in the conditions of farms for growing and fattening pigs in the Poltava region.Characteristic of all cases of death of animals was uneven redness and slight thickening of the skin in the abdomen. The increase and uneven coloration pdsalvy, tracheal, inguinal lymph nodes.Lungs with signs of catarrhal pneumonia with lesions predominantly cranial lobes. Some areas of dark red color with a bluish tint, more dense consistency, fall on a common surface, in the lumen of the bronchial – mucous mass. The other part of the body gets mild tuberosity at the age of 1.5 months and more intelligible – at the age of 3 months. In all cases of death of pigs, the pericardium and the pleura with hemorrhage. The spleen is diffusely dark red. The buds are light brown with areas of bluish color. At the age of 1.5 months on the mucosa of a thick intestine was rounded multiple small formations, protruding into the lumen of the intestine.

Detection of pathogens in Boidae and Pythonidae with and without respiratory disease

Respiratory diseases in boid snakes are common in captivity, but little information is available on their aetiology. This study was carried out to determine the occurrence of lung associated pathogens...

Pleuritis in slaughter pigs: Relations between lung lesions and bacteriology in 10 herds with high pleuritis

Pleuritis in slaughter pigs has increased in recent years in the Netherlands. The aim of the present study was to determine what respiratory pathogens were involved in pleuritis. In total, lungs of 968 slaughter pigs from 10 herds with high prevalence of pleuritis were morphologically examined for size, location, and type of lesions. Moreover, histology and bacteriology were performed. Examination of gross lung lesions showed 45% pleuritis, 14% pleuropneumonia and 38% catarrhal pneumonia. Peribronchiolar cuffing was found in 61 of 142 samples. Actinobacillus pleuropneumoniae was cultured from 22 lung samples from four herds. Pasteurella multocida was cultured from 55 lung samples in eight herds. No specific pattern with respect to the causal pathogens was found. In conclusion, no single infectious cause of pleuritis was found. A variety of infectious agents combined with environmental factors should be considered as a cause of pleuritis.

Expression of Class II Major Histocompatibility Complex Molecules in Chronic Pulmonary Mycoplasma bovis Infection in Cattle

Pulmonary inflammation often results in expression of the class II major histocompatibility complex (MHCII) by both professional antigen-presenting cells (APCs; histiocytes and lymphocytes) and non-professional APCs (respiratory epithelium and endothelium). In this study lesions from 17 cases of bovine chronic pneumonia, associated with Mycoplasma bovis infection, were examined immunohistochemically for M. bovis antigen and MHCII expression. Ten cases of chronic necrosuppurative bronchopneumonia (NBP) were shown to be characterized by abundant perinecrotic M. bovis antigen associated with scant MHCII expression by degenerate leucocytes. Seven cases of chronic catarrhal bronchointerstitial pneumonia (CBP) showed prominent MHCII expression by both professional APCs and respiratory epithelium, in the absence of intralesional M. bovis immunolabelling. The results suggest that prominent MHCII expression by both professional and non-professional APCs plays a role in the pathogenesis of M. bovis-induced CBP. Conversely, the role of MHCII expression in necrosuppurative foci typical of M. bovis-associated NBP can be considered negligible.

Experimental Burkholderia pseudomallei infection of pigs.

Experimental infection with Burkholderia pseudomallei was successfully produced after a single intravenous challenge of 2-month-old pigs with a dose of 5.0 x 10(9) bacterial cells. Clinical, paraclinical and morphological findings of the infectious process and post-infectious immunity were examined up to day 30 post infection (p.i.). A transient and short hyperthermia accompanied by enhanced and longer demonstrated pulse frequency. An increased erythrocyte sedimentation rate and tachypnea were observed too after clinical examination. The infection starts with significant leucopenia, and a reduced number of alveolar and peritoneal macrophages which have been overcome in the latest intervals of infection. In contrast, the phagocytic activity of leucocytes was statistically increased during the course of infection and up to day 15 p.i. in the case of alveolar macrophages. Burkholderia pseudomallei was able to colonize the lungs during the whole experiment and was only present 3 days in the spleen and mesenterial lymph nodes (MLN). Significant antibody response was developed as early as day 7 p.i. Hyperaemia, haemorrhages and necrotic foci were found in the brain, liver spleen and MLN. Lung tissue was also hyperaemic, with formation of small abscesses and signs of catarrhal pneumonia. Data obtained in this study revealed that B. pseudomallei causes a chronic generalized infection in pigs, even after intravenous challenge.

Experimental mixed infection of rabbits with Yersinia enterocolitica and Listeria monocytogenes.

Experimental mixed infection was reproduced in rabbits after per os infection with Yersinia enterocolitica serotype 0:3 cells. Four days later some of animals were re-infected orally with Listeria monocytogenes serotype 4b cells. A third group of healthy rabbits was also infected per os with Listeria monocytogenes. The infectious process was followed dynamically from days 1-28. The experimental animals were examined for clinical, paraclinical and morphological findings. Augmentation of body temperature and alveolar macrophage number, a decreased number of peritoneal macrophages, leucopenia as well as purulent meningoencephalitis, catarrhal pneumonia, lienitis, lymphadenitis and enteritis were detected after experimental mixed infection. Both types of macrophages demonstrated a weak bactericidal activity against Yersinia enterocolitica and a highly expressed killing effect against Listeria monocytogenes. Yersinia and Listeria cells were isolated from the viscera and brain. Both species of bacteria were established intracellularly in the macrophages by electron-microscopic examination. The data received showed that mixed Yersinia enterocolitica 0:3 and Listeria monocytogenes 4b infection of rabbits runs with transitory hyperthermia as a generalized infection and is similar to the Listeria mono-infection. The immunosuppressive effect induced by oral Yersinia enterocolitica infection of rabbits promotes the expression of listerious agents.

Arthritis after experimental infection with Yersinia enterocolitica 0:3 in rabbits.

Arthritis in rabbits was caused after experimental oral infection with Yersinia enterocolitica (serotype 0:3, biotype 4, pYV+). Clinical and laboratory signs, bacterial dissemination to the viscera, immune response and morphological findings were studied from day 1 to day 40 post-infection (p.i.). Augmentation of body temperature and erythrocyte sedimentation rate occurred on day 1, and on day 8 p.i. was accompanied by leucopenia. The number of alveolar macrophages was increased up to the 15th day p.i., in contrast to peritoneal macrophage numbers. Extensive bacterial colonization of the internal organs was detected at necropsy until the end of the experiment. Analysis of the cell immune response revealed activation of B cells in peripheral blood, spleen and thymus as well as augmentation of T-cell number in the lymphoid organs examined on days 15, 28 and 40 p.i. Histological changes typical of a generalized infection, such as purulent meningoencephalitis, catarrhal pneumonia and lymphadenitis, were observed. Clinical and morphological manifestations of arthritis were also established. The results obtained show that Y. enterocolitica (serotype 0:3, pYV+) induces a generalized, non-lethal infection in Chinchilla rabbits, complicated by arthritis.

The pathological effect of the Bordetella dermonecrotic toxin in mice.

The effect of dermonecrotic toxin (DNT) expression of Bordetella bronchiseptica was studied in mice by comparing the pathology induced by a wild type strain with that induced by an isogenic DNT- strain in which part of the structural gene has been replaced by an antibiotic resistance cassette. While extracts of strain B58 proved toxic in intravenously inoculated mice, similar extracts from strain B58GP had lost toxic activity. The parent (B58) and the mutant (B58GP) strains of B. bronchiseptica each possessed comparable virulence for mice. These findings confirmed that DNT production was successfully abolished in strain B58GP while other virulence characteristics required for pathogenicity in mice remained intact, at a comparable level to the parent strain. Turbinate atrophy was observed in mice infected with the DNT+ strain, but not in those infected with the DNT- strain. This indicates that DNT is the cause of turbinate atrophy in the mice and not other factors produced by phase I strains of B. bronchiseptica. B. bronchiseptica DNT showed a lienotoxic effect (lymphocyte depletion and a reduction in the intensity of extramedullar haemocytopoieis) that is considered to adversely alter the immune function of the host animal. In mice infected with strain B58GP, catarrhal pneumonia with characteristic lympho-histiocytic peribronchial and perivascular infiltration was noticed. In mice infected with strain B58, large necrotic areas were seen surrounded by an inflammatory reaction. The DNT appears to directly damage lung tissues, at least in mice. DNT production seems to enhance the establishment of B. bronchiseptica in the lungs, presumably by reducing the local resistance and causing severe local damage to the lung tissues.

Pathological Lesions in the Right and Left Porcine Lung: Evaluation of an Alternative Method for Scoring Pneumonic Lesions based on Right Lung Examination

Plucks from 2,372 sows, gilts and slaughterswine (originating from 3 independent sources) were evaluated for presence and severeness of 6 different pathological entities. Results were calculated for each of the lungs separately and compared to the combined findings of both lungs. Both qualitatively (comparing relative test sensitivities) and quantitatively (comparing lung scores), the right lung results were more optimal than the left lung outcomes and relatively consistent among the 3 data sets. The over-all right lung relative sensitivities for the detection of catarrhal pneumonia or chronic pleuritis were 81.3% and 72.0%, respectively. The over-all differences in the right minus left lung scores for the 2 lesions were +13.0% and +9.0%, respectively. The necessary sample size of right lungs to detect at least 1 lung with catarrhal pneumonia or chronic pleuritis is presented along with a method for calculating confidence intervals.

Comparison of pathological signs of disease in specific-pathogen-free calves after inoculation of the respiratory tract with Ureaplasma diversum or Mycoplasma canis

To confirm the pathogenic role of Ureaplasma diversum in respiratory disease of calves, we inoculated caesarean-delivered, colostrum-deprived calves intranasally with a dose of 10(7) colour-changing units (CCU) or endobronchially with a dose of 10(10) CCU. Clinical signs of respiratory disease were not observed, but in the endobronchially inoculated calves, thick cuffs of round cells surrounded the bronchi, bronchioli and blood vessels, and a lobular catarrhal pneumonia developed. It was concluded that the pathogenicity of U. diversum can be demonstrated after endobronchial but not after intranasal inoculation. Similar calves were inoculated endobronchially with a dose of 2 x 10(10) colony-forming units of Mycoplasma canis. Clinical signs of respiratory disease were not observed. At day 2 after inoculation, only slight pathological signs of respiratory disease were detected, and these disappeared at day 9. M. canis was not recovered from the lungs. Hence, M. canis could not be clearly identified as a pathogen in respiratory disease of calves. By comparing the results of the various experiments, we concluded that thin cuffs of round cells in the lungs can indicate mycoplasma infections, but that these are not necessarily pathognomonic.

Pathological, ultrastructural, and immunohistochemical changes caused by Lelystad virus in experimentally induced infections of mystery swine disease (synonym: Porcine epidemic abortion and respiratory syndrome (PEARS))

The pathogenicity and pathogenesis of Lelystad virus was studied in six 6-day-old SPF piglets. A third passage of the agent was propagated on porcine alveolar macrophages and intranasally inoculated into pigs. Pigs were killed at hours 24, 48, 60, and 72, and on days 6 and 8 after inoculation. From day 2 on pigs developed diffuse interstitial pneumonia with focal areas of catarrhal pneumonia, and from this day on splenic red pulp macrophages were enlarged and vacuolated. Lelystad virus was re-isolated from the lungs of infected pigs from day 2 after inoculation. Lelystad virus antigens were detected by immunohistochemical techniques in bronchiolar epithelium and alveolar cells, and in spleen cells of infected pigs from day 2 after inoculation. Ultrastructural examination of tissues by electron microscopy revealed degenerating alveolar macrophages and epithelial cells in lungs and nasal mucosa, with excessive vacuolation of the endoplasmic reticulum. Although the respiratory tract seems to be the target organ for this virus, macrophages in other organs, such as the spleen, can also be infected. This preference for macrophages may impair immunological defences.

Clinical and pathological observations on spontaneous bovine respiratory syncytial virus infections in calves

A clinical, pathological and microbiological study was made of acute spontaneous bovine respiratory syncytial virus infection in calves. Characteristic features were atelectatic areas, which had an exudative and, or, necrotising bronchiolitis with syncytial giant cells in the epithelial lining and in the lumina of these bronchioles. Restricted to these areas both bronchiolar and alveolar immunofluorescence for bovine respiratory syncytial virus were seen. Complications were severe interstitial oedema, interstitial emphysema and a catarrhal or fibrinous pneumonia due to secondary bacterial invasion.

Studies on the pathogenicity of Acholeplasma axanthum in swine.

Acholeplasma axanthum sp. was isolated from the lung of swine with catarrhal pneumonia. Clinical symptoms of respiratory disease, gross and histological lesions of pneumonia, as well as serological response were produced by intranasal inoculation of ;miniature pigs' with the supernatant of lung suspension containing Acholeplasma axanthum and by a 48 hr. broth culture of the strain.A similar picture of disease was observed in animals held in contact with the animals inoculated with untreated lung suspension. Acholeplasma axanthum was isolated from the nasal cavity, lung and peribronchial lymph nodes 7-41 days after inoculation. No lesions were observed after inoculation of pigs with the supernatant of lung suspension pretreated with oxytetracycline or chloroform, and no successful isolation of Acholeplasma axanthum could be achieved after this treatment.

Occurrence and possible role of Moraxella species in pigs.

Bacteriological examination of material from 4500 post mortem examined suckling pigs from 17 herds resulted in the isolation of a haemolytic Moraxella species in 81 cases (1.8 per cent). In 43 instances Moraxella was isolated in pure culture and 34 pigs apparently succumbed to a generalized Moraxella infection. Mixed infections occurred in 11 pigs and 27 isolations were from mucous membranes. A tendency to a prevalence among pigs born by primiparae was found. Seasonal variation with the highest frequency in the winter‐months was obvious. The infections occurred sporadically in 13 out of 17 herds. The Moraxella was predominantly found among pigs less than one week old, 73 of all the isolates and 94 per cent of the generalized infections were found in this age group. Besides generalized infections, Moraxella was isolated from four cases of catarrhal pneumonia, three cases of arthritis and three abscesses. The morphology and the biochemical properties of the isolated strains are described. In a preliminary inoculation‐experiment with gnotobiotic pigs the employed Moraxella‐strain was able to establish itself in the pharynx, but no clinical symptoms or pathological lesions were produced. It is concluded, that the described Moraxella species like some other gram‐negative related species can act as an opportunistic pathogen in pigs and occasionally cause generalized or localized infections in piglets—mainly among predisposed and debilitated individuals.