Sarcina -like bacteria, Clostridium fallax and Clostridium sordellii in lambs with abomasal bloat, haemorrhage and ulcers

Sarcina sp. as a presumptive cause of fatal acute gastric dilation and gastric emphysema in rhesus macaques

A 4-y-old female and 3-y-old male rhesus macaque (Macaca mulatta), both housed in the same facility, died unexpectedly within 2 wk. Postmortem examination revealed severe gastric dilation in both macaques and gastric emphysema in the female macaque. Histologically, bacteria consistent with Sarcina sp. were present in both macaques within the lungs and lumen of the trachea, esophagus, and gastrointestinal (GI) tract without associated inflammation. Additionally, in the female macaque, the bacteria were found in the gastric mucosa and associated with emphysematous spaces in the gastric wall without associated inflammation. PCR and Sanger sequencing of amplicons were subsequently performed on GI contents and non-alimentary tissues from the 2 affected monkeys and on comparative samples from unaffected rhesus monkeys in the same facility and an adjacent primate facility. The cases were compared using the 2-tailed Fisher exact test (p-value at 95% confidence). PCR identified Sarcina in GI contents of both affected and unaffected monkeys (p = 0.6084) and in non-alimentary tissues of affected monkeys only (p = 0.0083). These results suggest that the presence of Sarcina sp. in non-alimentary tissues is associated with gastric distension, gas accumulation, and unexpected death in nonhuman primates.

Species and Strain Variability among Sarcina Isolates from Diverse Mammalian Hosts

Sarcina spp. has been isolated from the gastrointestinal tracts of diverse mammalian hosts. Their presence is often associated with host health complications, as is evident from many previously published medical case reports. However, only a handful of studies have made proper identification. Most other identifications were solely based on typical Sarcina-like morphology without genotyping. Therefore, the aim of this work was culture detection and the taxonomic classification of Sarcina isolates originating from different mammalian hosts. Sarcina-like colonies were isolated and collected during cultivation analyses of animal fecal samples (n = 197) from primates, dogs, calves of domestic cattle, elephants, and rhinoceroses. The study was carried out on apparently healthy animals kept in zoos or by breeders in the Czech Republic and Slovakia. Selected isolates were identified and compared using 16S rRNA gene sequencing and multi-locus sequence analysis (MLSA; Iles, pheT, pyrG, rplB, rplC, and rpsC). The results indicate the taxonomic variability of Sarcina isolates. S. ventriculi appears to be a common gut microorganism in various captive primates. In contrast, a random occurrence was also recorded in dogs. However, dog isolate N13/4e could represent the next potential novel Sarcina taxonomic unit. Also, a potentially novel Sarcina species was found in elephants, with occurrences in all tested hosts. S. maxima isolates were detected rarely, only in rhinoceroses. Although Sarcina bacteria are often linked to lethal diseases, our results indicate that Sarcina spp. appear to be a common member of the gut microbiota and seem to be an opportunistic pathogen. Further characterization and pathogenic analyses are required.

[3 cases of abomasitis in calves associated with Sarcina sp. infection]

In this case report - to the best knowledge of the authors for the first time in the German-speaking region - 3 calves with ulcerating or emphysematous abomasitis respectively are presented, in which intralesional bacteria of the Sarcina species were identified. The unusual appearance of these bacteria is described, their etiopathogenic relevance discussed.

Detection and molecular characterization of Clostridium perfringens, Paeniclostridium sordellii and Clostridium septicum from lambs and goat kids with hemorrhagic abomasitis in Turkey

BACKGROUND

The pathogenic Clostridia cause neurotoxic, histotoxic and enterotoxic infections in humans and animals. Several Clostridium species have been associated with abomasitis in ruminants. The present study aimed to investigate the frequency, and the presence of virulence genes, of Clostridium perfringens, Paeniclostridium sordellii and Clostridium septicum in lambs and goat kids with hemorrhagic abomasitis.

RESULTS

A total of 38 abomasum samples, collected from lambs and goat kids of 1 week to 1 month of age in different farms located in eastern Turkey between 2021 and 2022, were evaluated by histopathology, culture and PCR. At necropsy, the abomasum of the animals was excessively filled with caseinized content and gas, and the abomasum mucosa was hemorrhagic in varying degrees. In histopathological evaluation, acute necrotizing hemorrhagic inflammation was noted in abomasum samples. The examination of swab samples by culture and PCR revealed that C. perfringens type A was the most frequently detected species (86.84%) either alone or in combination with other Clostridium species. P. sordellii, C. perfringens type F and C. septicum were also harboured in the samples, albeit at low rates. Beta2 toxin gene (cpb2) was found in three of C. perfringens type A positive samples.

CONCLUSION

It was suggested that vaccination of pregnant animals with toxoid vaccines would be beneficial in terms of protecting newborn animals against Clostridial infections. This study investigated the presence of clostridial toxin genes in abomasal samples for the first time in Turkey.

Diagnosis of Sarcina ventriculi-derived haemorrhagic abomasitis in lambs by histopathology and real-time PCR

This study aimed to diagnose Sarcina ventriculi in lambs with haemorrhagic abomasitis using histopathological and real-time PCR methods. The material used in this study consisted of 43 abomasum tissues recovered from lambs presenting bleeding, ulcer, gas or a combination of these in the abomasum, that were brought for necropsy to the Department of Pathology of the Veterinary Faculty, Selcuk University. The recovered samples were stored in a 10% formaldehyde solution for histopathological examinations and in Eppendorf tubes at −20 °C for PCR examinations. All the samples were analyzed by histopathological and PCR methods. While S. ventriculi pyruvate decarboxylase (PDC) amplicon was determined by real-time PCR in 17 cases, the packaged form of Sarcina-like bacteria was found microscopically in 3 cases only. In this study, the diagnosis of S. ventriculi in cases of lambs presenting bleeding, ulcers and gas in the abomasum or haemorrhagic abomasitis simultaneously at the necropsy was performed using histopathological and real-time PCR methods; in parallel, the real-time PCR method for the diagnosis of S. ventriculi-derived haemorrhagic abomasitis in lambs was also optimized.

A Sarcina bacterium linked to lethal disease in sanctuary chimpanzees in Sierra Leone

Human and animal infections with bacteria of the genus Sarcina (family Clostridiaceae) are associated with gastric dilation and emphysematous gastritis. However, the potential roles of sarcinae as commensals or pathogens remain unclear. Here, we investigate a lethal disease of unknown etiology that affects sanctuary chimpanzees (Pan troglodytes verus) in Sierra Leone. The disease, which we have named "epizootic neurologic and gastroenteric syndrome" (ENGS), is characterized by neurologic and gastrointestinal signs and results in death of the animals, even after medical treatment. Using a case-control study design, we show that ENGS is strongly associated with Sarcina infection. The microorganism is distinct from Sarcina ventriculi and other known members of its genus, based on bacterial morphology and growth characteristics. Whole-genome sequencing confirms this distinction and reveals the presence of genetic features that may account for the unusual virulence of the bacterium. Therefore, we propose that this organism be considered the representative of a new species, named "Candidatus Sarcina troglodytae". Our results suggest that a heretofore unrecognized complex of related sarcinae likely exists, some of which may be highly virulent. However, the potential role of "Ca. S. troglodytae" in the etiology of ENGS, alone or in combination with other factors, remains a topic for future research.

Clostridium sordellii-associated gas gangrene in 8 horses, 1998-2019

Gas gangrene occurs in several animal species and is caused by one or more clostridial species. In horses, the disease is most often caused by Clostridium perfringens type A. Although Clostridium sordellii has been associated with gas gangrene in ruminants and humans, cases of the disease associated with this microorganism have not been described in horses, to our knowledge. We report herein 8 cases of gas gangrene caused by C. sordellii in horses. These cases were characterized by myonecrosis and cellulitis, associated with systemic changes suggestive of toxic shock. The diagnosis was confirmed by gross and microscopic changes combined with anaerobic culture, fluorescent antibody test, immunohistochemistry, and/or PCR. The predisposing factor in these cases was an injection or a traumatic skin injury. C. sordellii should be considered as a possible etiologic agent in cases of gas gangrene in horses.

Sarcina Organisms in the Upper Gastrointestinal Tract: A Report of 3 Cases With Varying Presentations

Sarcina species are anaerobic gram-positive cocci rarely seen in the upper gastrointestinal tract and associated with delayed gastric emptying. We present 3 cases of Sarcina infection with varying clinical presentations including the first reported case of Sarcina in a patient with eosinophilic esophagitis. Although the pathogenesis of Sarcina is unclear, awareness of the bacteria is important as they can usually only be detected on histopathologic examination of upper gastrointestinal biopsies. Treatment in symptomatic patients may prevent severe complications such as emphysematous gastritis and gastric perforation.

Short communication: Survival of replacement kids from birth to mating on commercial dairy goat farms in New Zealand

Commercial dairy goat systems rely on the successful rearing of kids for herd replacement. The objectives of this study were to (1) determine survival from birth until mating for a large cohort of commercial dairy goat kids; (2) descriptively summarize the causes of mortality and removal from the herd during this period; and (3) compare actual (determined by postmortem examination) and suspected (farmer-reported) causes of mortality. A total of 1,262 female kids were enrolled at birth on 16 commercial dairy goat farms in New Zealand. Median ages at weaning and mating were 86 d [minimum = 54, quartile (Q)1 = 78, Q3 = 97, maximum = 144] and 223 d (minimum = 183, Q1 = 208, Q3 = 237, maximum = 310), respectively. Overall, 87.1% (1,099/1,262) of kids remained on farm at mating, 10.4% (131/1,262) died or were euthanized, and 2.5% (32/1,262) were lost to follow-up or sold. Mortality risk was greatest in early life, with more than 90% of deaths occurring before weaning. Mortality from enrollment to mating varied between farms (minimum = 0%, Q1 = 5.9%, median = 8.9%, Q3 = 15.8%, maximum = 20.5%). The leading cause of death was gastrointestinal disorders (33.6%, 36/107), followed by disbudding-related injury (15.9%, 17/107), and septicemia (12.1%, 13/107). Farmers correctly identified approximately half of the deaths attributed to gastrointestinal disorders (56.0%, 14/25) and disbudding-related injury (44.4%, 4/9), but were less successful at diagnosing septicemia (0%, 0/5), starvation or dehydration (0%, 0/4), and suffocation (18.8% 3/16). This is the largest cohort of dairy goat kids to be systematically followed over time to confirm survival until mating and to determine causes of death by postmortem examination. We found that kid mortality was highest during the preweaning period and there was often a discrepancy between farmer-perceived and actual cause of death. Postmortem examinations should be more widely used to establish causes of death and inform on-farm strategies to reduce kid mortality.

Abomasal and Third Compartment Ulcers in Ruminants and South American Camelids

Abomasal ulcers are frequent incidental findings in necropsies of domestic ruminants and South American Camelids (SAC) or in slaughter animals and are a frequent cause of death in the most affected group of cattle, veal calves. Their true prevalence and significance is unknown owing to limitations in diagnosing the condition in live animals. This article discusses types of ulcers, possible causes of ulceration, and the clinical consequences, symptoms, and differential diagnoses, as well as further diagnostics in cattle, small ruminants and SAC. The limited treatment options and possibilities for prevention are reviewed.

Gastric Dilatation Associated with Gastric Colonization with Sarcina-Like Bacteria in a Cat with Chronic Enteritis

An 11 yr old spayed female domestic longhair cat was presented for an acute onset of vomiting. Abdominal radiographs and ultrasound revealed severe gastric dilatation (GD) without evidence of gastric outflow obstruction. On esophagogastroduodenoscopy, the duodenal mucosa was mildly erythematous, and a moderate, diffuse, chronic enteritis was found by histological examination of duodenal biopsies. Large numbers of Sarcina-like bacteria without associated inflammation were present in gastric mucosal biopsies. To the authors' knowledge, this is the first report of GD associated with colonization by Sarcina-like bacteria in a cat. Gastric colonization by Sarcina-like bacteria should be suspected when cats are presented with acute onset of GD and vomiting.

Sudden Death Associated with Clostridium sordellii in Captive Lions (Panthera leo)

In the spring of 2003, a series of sudden deaths in a group of adult lions ( Panthera leo) with a previous history of depression, inanition, and lethargy, was investigated. Five animals died within 24 to 36 hours after onset of signs of disease. Serologic screening for viral disease detection was negative, evidence of parasites was not detected, and results of a complete blood count and serum biochemical analysis were within reference intervals in all lions. The most relevant lesions observed were multiple areas of necrosis and hemorrhage in the intestinal outer muscular layer, and cellulitis with an intense bloody edema in the mesenteric and the pericardial fat tissue. On the basis of the fulminant course of the disease, the gross and histologic findings, and the isolation and identification of Clostridium sordellii, a diagnosis of infectious myositis and cellulitis associated with acute clostridiosis was made. To the authors' knowledge, this is the first report of sudden death associated with C. sordellii in felines.

The effect of helminth infection on the microbial composition and structure of the caprine abomasal microbiome

Haemonchus contortus is arguably the most injurious helminth parasite for small ruminants. We characterized the impact of H. contortus infection on the caprine abomasal microbiome. Fourteen parasite naive goats were inoculated with 5,000 H. contortus infective larvae and followed for 50 days. Six age-matched naïve goats served as uninfected controls. Reduced bodyweight gain and a significant increase in the abosamal pH was observed in infected goats compared to uninfected controls. Infection also increased the bacterial load while reducing the abundance of the Archaea in the abomasum but did not appear to affect microbial diversity. Nevertheless, the infection altered the abundance of approximately 19% of the 432 species-level operational taxonomic units (OTU) detected per sample. A total of 30 taxa displayed a significantly different abundance between control and infected goats. Furthermore, the infection resulted in a distinct difference in the microbiome structure. As many as 8 KEGG pathways were predicted to be significantly affected by infection. In addition, H. contortus-induced changes in butyrate producing bacteria could regulate mucosal inflammation and tissue repair. Our results provided insight into physiological consequences of helminth infection in small ruminants and could facilitate the development of novel control strategies to improve animal and human health.

Clostridium sordellii Lethal-Toxin Autoprocessing and Membrane Localization Activities Drive GTPase Glucosylation Profiles in Endothelial Cells

Clostridium sordellii is a bacterium that can infect humans and cause serious disease and death. The principle virulence factor associated with clinical symptoms is a large protein toxin known as lethal toxin. The mechanism of lethal-toxin intoxication is assumed to be similar to that of the homologous toxins from C. difficile, but very few studies have been done in the context of endothelial cells, a relevant target in C. sordellii infections. This study was designed to test the role of the lethal-toxin enzymatic activities and membrane localization in endothelial cell toxicity and host substrate modification.

Clostridium sordellii infections cause gangrene and edema in humans and gastrointestinal infections in livestock. One of the principle virulence factors is TcsL, a large protein toxin which glucosylates host GTPases to cause cytopathic and cytotoxic effects. TcsL has two enzymatic domains, an N-terminal glucosyltransferase domain (GTD) and an autoprocessing domain responsible for release of the GTD within the cell. The GTD can then use its N-terminal membrane localization domain (MLD) for orientation on membranes and modification of GTPases. This study describes the use of conditionally immortalized murine pulmonary microvascular endothelial cells as a model for the study of TcsL functional activities. Point mutations that disrupt the glucosyltransferase, autoprocessing, or membrane localization activities were introduced into a recombinant version of TcsL, and the activities of these mutants were compared to those of wild-type toxin. We observed that all mutants are defective or impaired in cytotoxicity but differ in their modification of Rac1 and Ras. The data suggest a model where differences in GTPase localization dictate cellular responses to intoxication and highlight the importance of autoprocessing in the function of TcsL.

IMPORTANCEClostridium sordellii is a bacterium that can infect humans and cause serious disease and death. The principle virulence factor associated with clinical symptoms is a large protein toxin known as lethal toxin. The mechanism of lethal-toxin intoxication is assumed to be similar to that of the homologous toxins from C. difficile, but very few studies have been done in the context of endothelial cells, a relevant target in C. sordellii infections. This study was designed to test the role of the lethal-toxin enzymatic activities and membrane localization in endothelial cell toxicity and host substrate modification.

Clinical, microbiological and histological findings in lambs affected by 'salivary abomasum disease'

'Salivary abomasum disease' is a common syndrome in Greece affecting lambs and kids from three to 17 days of age. In this case series, we present clinical and laboratory findings from 37 affected lambs presented alive and subsequently euthanased for welfare reasons and necropsied, and also from 24 other lambs submitted dead that were also necropsied. The clinical signs in the 37 lambs presented alive included lethargy (100 per cent), absence of sucking (83.8 per cent), weakness (37.8 per cent), abdominal distension (40.5 per cent) and increased frequency of urination (24.3 per cent). Diarrhoea was not observed in any affected lambs. At necropsy of these 37 lambs, the abomasum was distended with gas (70.3 per cent), saliva (43.2 per cent) along with mixed milk clots and gastric secretions; while multiple small mucosal and serosal haemorrhages with blood clots ('coffee grains') were recorded (91.9 per cent). Eight of 37 lambs that were examined alive, had elevated blood urea nitrogen concentrations (21.6 per cent). The pH of the abomasal contents ranged from 1.0 to 2.8; Escherichia coli was cultured from six of 37 (16.2 per cent) abomasal fluid samples. A mild to moderate inflammatory cell infiltrate was present in the mucosal lamina propria of 13 of 15 abomasal samples (86.6 per cent). Kidneys were paler than normal in 13 of the total 61 lambs necropsied (21.3 per cent); while acute tubular necrosis was evident on histopathological examination of 11 of 12 examined pale kidneys (91.6 per cent). The low abomasal pH and reported successful treatment with oral sodium bicarbonate suggest that metabolic acidosis may develop during the disease; however, further studies, including blood gas analysis, and determination of D- and L-lactic acid concentrations, are necessary to confirm this hypothesis.

Health management of ewes during pregnancy

The objectives of health management of ewes during pregnancy are as follows: (i) successful completion of pregnancy at term, (ii) birth of healthy and viable lambs, with optimal birth and potential weaning bodyweight, (iii) optimum milk production during the subsequent lactation and (iv) improved management in relation to drug residues in animal products. Knowledge of the physiological background of pregnancy in ewes: changes, mechanisms and interactions, during pregnancy is important for the overall health management of ewes during pregnancy. Health management of pregnant ewes includes diagnosis of pregnancy and evaluation of the number of foetuses borne, which will support strategies for subsequent management of the flock. Nutritional management of ewes depends upon the stage of lactation and specifically aims to (i) prevention of pregnancy toxaemia and other metabolic diseases during the peri-partum period, (ii) formation of colostrum in appropriate quantity and quality, (iii) production of lambs with normal future birth bodyweight and (iv) support of increased milk yield during the subsequent lactation. At the end of lactation, udder management of pregnant ewes includes its clinical examination, culling of ewes considered unsuitable for lactation and, possibly, the intramammary administration of antibiotics; objectives of that procedure are (i) to cure infections which have occurred during the previous lactation and (ii) to prevent development of new mammary infection during the dry period. Management of abortions includes the correct and timely diagnosis of the causative agent of the disorder, as well as the strategic administrations of chemotherapeutic agents, aiming to prevent abortions in flocks with confirmed infection with an abortifacient agent, especially if no appropriate vaccinations had been carried out before the mating season. During the final stage of pregnancy, health management of ewes includes administration of appropriate anthelmintic drugs, aiming to eliminate gastrointestinal helminthes (thus, increasing production output of ewes) and preventing the built-up of parasitic burdens in the environment (thus, reducing infection of lambs during their neonatal period). Vaccinations of pregnant ewes aim to protect these animals, as well as their offspring, especially against diseases which are a frequent cause of neonatal mortality (e.g., clostridial infections). Health management also aims to prevent the main metabolic disorders of pregnant ewes (i.e., pregnancy toxaemia and hypocalcaemia), as well as to monitor flocks for development of these disorders. Health management of pregnant ewes is completed with application of husbandry practices before the start of the lambing season. Finally, in some cases, health management may include induction and synchronisation of lambings, which is a management or therapeutic procedure.

Sarcina organisms in the gastrointestinal tract: a clinicopathologic and molecular study

Sarcina organisms were first observed in and recorded from the stomach contents of a patient suffering from vomiting by John Goodsir in 1842. Since that time, their fine structure, phylogenetic classification, and biochemical characteristics have been described. Although numerous cases of fatal disease have been attributed to this organism in the veterinary literature, only a few human cases have been documented. As a result, whether this organism causes disease in humans has not been definitively established. We report the clinicopathologic findings in a series of 5 patients with Sarcina-like organisms identified in upper gastrointestinal endoscopic biopsies with molecular confirmation. Our findings have shown that the organism is most commonly found in patients with a history of gastric outlet obstruction or delayed gastric emptying. Although many of the patients do not demonstrate direct mucosal injury from the organism, the presence of a concurrent gastric ulcer puts the patient at increased risk for complications such as emphysematous gastritis or perforation. The finding of Sarcina organisms should prompt further investigation for functional causes of gastric outlet obstruction and delayed gastric emptying, such as occult malignancy.

Metagenome plasticity of the bovine abomasal microbiota in immune animals in response to Ostertagia ostertagi infection

Infections in cattle by the abomasal nematode Ostertagia ostertagi result in impaired gastrointestinal function. Six partially immune animals were developed using multiple drug-attenuated infections, and these animals displayed reduced worm burdens and a slightly elevated abomasal pH upon reinfection. In this study, we characterized the abomasal microbiota in response to reinfection using metagenomic tools. Compared to uninfected controls, infection did not induce a significant change in the microbial community composition in immune animals. 16S rRNA gene-based phylogenetic analysis identified 15 phyla in the bovine abomasal microbiota with Bacteroidetes (60.5%), Firmicutes (27.1%), Proteobacteria (7.2%), Spirochates (2.9%), and Fibrobacteres (1.5%) being the most predominant. The number of prokaryotic genera and operational taxonomic units (OTU) identified in the abomasal microbial community was 70.8±19.8 (mean ± SD) and 90.3±2.9, respectively. However, the core microbiome comprised of 32 genera and 72 OTU. Infection seemingly had a minimal impact on the abomasal microbial diversity at a genus level in immune animals. Proteins predicted from whole genome shotgun (WGS) DNA sequences were assigned to 5,408 Pfam and 3,381 COG families, demonstrating dazzling arrays of functional diversity in bovine abomasal microbial communities. However, none of COG functional classes were significantly impacted by infection. Our results demonstrate that immune animals may develop abilities to maintain proper stability of their abomasal microbial ecosystem. A minimal disruption in the bovine abomasal microbiota by reinfection may contribute equally to the restoration of gastric function in immune animals.

Examination of equine glandular stomach lesions for bacteria, including Helicobacter spp by fluorescence in situ hybridisation

Background

The equine glandular stomach is commonly affected by erosion and ulceration. The aim of this study was to assess whether bacteria, including Helicobacter, could be involved in the aetiology of gastric glandular lesions seen in horses.

Results

Stomach lesions, as well as normal appearing mucosa were obtained from horses slaughtered for human consumption. All samples were tested for urease activity using the Pyloritek^® assay, while mucosal bacterial content was evaluated using Fluorescence In Situ Hybridisation. In selected sub samples, bacteria characterisation was pursued further by cloning and sequencing. Mucosal lesions were found in 36/63 stomachs and included hyperplastic rugae, polypoid structures and focal erosions. None of the samples were tested positive for urease activity or for FISH using the Helicobacter genus specific probe. In samples of lesions, as well as normal samples, clones with 99% similarities to Lactobacillus salivarius and Sarcina ventriculi were found. Escherichia like bacterium clones and Enterococcus clones were demonstrated in one focal erosion. Based on a phylogenetic tree these clones had 100% similarity to Escherichia fergusonii and Enterococcus faecium. The Enterococcus were found colonising the mucosal surface, while E. fergusonii organisms were also demonstrated intraepithelial.

Conclusion

Gastric Helicobacter spp. could not be verified as being involved in lesions of the glandular stomach of the horse. Since E. fergusonii has been described as an emerging pathogen in both humans and animals, the finding of this bacterium in gastric erosion warrants further clarification to whether gastric infection with this type bacterium is important for horses.

Sarcina-like bacteria associated with bloat in young lambs and calves

Sarcina species are fastidious Gram-positive anaerobic bacteria that occur in cubical packets of eight or more cells. In 2006 to 2007, they were associated with cases of acute abomasal bloat in young lambs and calves. Two incidents were in lambs aged three to six weeks that were found dead, with one or two cases in each of a group of 15 and 100 lambs. Three incidents were recorded in small groups of calves up to 10 days of age, two cases in each incident, with the calves found dead or dying after a short illness characterised by bloat. Their gross lesions included emphysema and oedema of the abomasal wall, mucosal hyperaemia and haemorrhage, and rupture of the abomasum. Histological lesions included abomasitis with congestion, haemorrhage, emphysema and oedema. Bacteria characteristic of Sarcina species were observed in sections associated with the superficial mucosa of these cases, but the bacteria were not detected in cultures.

Tympany, acidosis, and mural emphysema of the stomach in calves: report of cases and experimental induction

Necropsy of 4 neonatal calves with a peracute syndrome of abdominal distention, diarrhea, dehydration, shock, and death revealed abomasal tympany, marked edema, hemorrhage, and emphysema of ruminal and abomasal walls and histopathologic lesions characteristic of forestomach acidosis. The presence of acid damage and the production of substantial quantities of gas strongly suggested that the pathogenesis of the syndrome involved exuberant fermentation of intragastric substrate. This supposition led to attempts to experimentally induce the syndrome by dosing neonatal calves with an alimentary tract flora, followed by milk replacer supplemented with excessive fermentable carbohydrate (D-glucose and cornstarch). Two of the 5 calves thus treated developed a syndrome very similar to that observed in naturally affected calves. Literature suggests involvement of several Clostridial species, Sarcina spp., and possibly other microbes or a combination thereof to be involved in very similar syndromes. Therefore it is suggested that this complex of lesions and clinical signs is not dependent on a single etiologic agent. Rather, it is proposed that the natural occurrence of disease requires a quantity of highly fermentable substrate (starch, glucose, lactose, etc.) and a bacterial flora that is capable of rapidly fermenting that particular substrate with a resultant production of gas and acid.

Variations in lethal toxin and cholesterol-dependent cytolysin production correspond to differences in cytotoxicity among strains of Clostridium sordellii

Clostridium sordellii is an emerging human pathogen and frequent contaminant of cadaver-derived tissue transplant material. Herein, we provide data suggesting the potential for severe C. sordellii-associated disease may be dictated by whether the specific strain produces lethal toxin (TcsL) or sordellilysin (SDL), a cholesterol-dependent cytolysin. The virulence factor profiles of 14 C. sordellii isolates were determined, and culture supernatant from six of the isolates was found to be cytotoxic to mammalian cells; yet, only one of these strains conferred cytotoxicity via production of TcsL. Cytotoxicity of TcsL- strains correlated with the production of sordellilysin, which was also recognized by an antiperfringolysin O antibody. However, supernatant from TcsL+, SDL- strains demonstrated a lower LD50 relative to TcsL-, SDL+ strains, suggesting the potential for severe C. sordellii-associated disease may be determined by the particular strain colonizing the host.

Clostridium fallax associated with sudden death in a 16-year-old boy

Clostridial myonecrosis or gas gangrene occurs most frequently in contaminated wounds following trauma or surgery. It is caused by a wide variety of Clostridium species, the most common being Clostridium perfringens. Spontaneous, non-traumatic clostridial myonecrosis is uncommon and is usually associated with gastrointestinal and haematological malignancy, diabetes mellitus and peripheral vascular disease. The case of a previously healthy 16-year-old boy with acute onset of gastrointestinal symptoms, who died of bacterial sepsis without apparent preceding trauma, is presented here. Clostridium fallax was identified as the most probable causative agent. As far as is known, this is the first report of fatal sepsis in humans due to C. fallax, which has been described only rarely as a cause of gas oedema in animals.

Clostridium sordellii lethal toxin is maintained in a multimeric protein complex

Clostridium sordellii lethal toxin (TcsL) is distinct among large clostridial toxins (LCTs), as it is markedly reduced in its rate of intoxication at pH 8.0 yet is cytotoxic at pH 4.0. Results from the present study suggest that TcsL's slow rate of intoxication at pH 8.0 is linked to formation of a high-molecular-weight complex containing dissociable pH 4.0-sensitive polypeptides. The cytosolic delivery of TcsL's enzymatic domain by using a surrogate cell entry system resulted in cytopathic effect rates similar to those of other LCTs at pH 8.0, further indicating that rate-limiting steps occurred at the point of cell entry. Since these rate-limiting steps could be overcome at pH 4.0, TcsL was examined across a range of pH values and was found to dissociate into distinct 45- to 55-kDa polypeptides between pH 4.0 and pH 5.0. The polypeptides reassociated when shifted back to pH 8.0. At pH 8.0, this complex was resistant to sodium dodecyl sulfate (SDS) and multiple proteases; however, following dissociation, the polypeptides became protease sensitive. Dissociation of TcsL, and cytotoxicity, could be blocked by preincubation with ethylene glycol bis(sulfosuccinimidylsuccinate), resulting in cross-linking of the polypeptides. TcsL was also examined at pH 8.0 by using SDS-agarose gel electrophoresis and transmission electron microscopy and was found to exist in a higher-molecular-weight complex which resolved at a size exceeding 750 kDa and also dissociated at pH 4.0. However, this complex did not reassemble following a shift back to pH 8.0. Collectively, these data suggest that TcsL is maintained in a protease-resistant, high-molecular-weight complex, which dissociates at pH 4.0, leading to cytotoxicity.

Are goats naturally resistant to gastric Helicobacter infection?

Gastric Helicobacter species are widespread and have been reported in wild and domestic mammals of different dietary habits such as humans, dogs, cats, macaques, mice, cheetahs, ferrets, swine and cattle. All have been associated with gastric pathologies. Recently, gastric Helicobacter species were shown to be widespread in cattle and swine in Europe, and there is a report of Helicobacter pylori in sheep in Italy. However, there are no reports of Helicobacter infection in the goat, another important domestic animal of human consumption. The aim of our study was to assess whether Helicobacter abomasal infection was common in goats slaughtered for human consumption. Infection was detected through PCR analysis of DNA extracted from gastric biopsies, using genus- and species-specific primers. Bovine and porcine gastric samples were also analyzed as positive controls. None of the 70 goats were positive for Helicobacter spp.; however, Candidatus Helicobacter bovis and Candidatus Helicobacter suis were detected in 85% of the bovine and 45% of the porcine samples, respectively. We discuss the possibility that goats may exhibit natural resistance to abomasal infection by Helicobacter spp.

pH-enhanced cytopathic effects of Clostridium sordellii lethal toxin

Clostridium sordellii lethal toxin (TcsL) is a large clostridial toxin (LCT) that glucosylates Ras, Rac, and Ral. TcsL differs from other LCTs because it modifies Ras, which does not cycle from cytosol to membrane. By using a suite of inhibitors, steps in cell entry by TcsL were dissected, and entry appears to be dependent on endosomal acidification. However, in contrast to TcdB, TcsL was substantially slower in its time course of entry. TcsL cytopathic effects (CPE) were blocked by bafilomycin A1 and neutralized by antiserum up to 2 h following treatment of cells with the toxin. The slow time course of intoxication and relatively high cytopathic dose were alleviated by exposing TcsL to acid pH, resulting in a time course similar to that of TcdB. The optimal pH range for activation was 4.0 to 5.0, which increased the rate of intoxication over 5-fold, lowered the minimal intoxicating dose by over 100-fold, and allowed complete substrate modification within 2 h, as shown by differential glucosylation. Fluorescence analysis of TcsL with 2-(p-toluidinyl) naphthalene-6-sulfonic acid as a probe suggested the acid pH stimulated a hydrophobic transition in the protein, a likely prelude to membrane insertion. Finally, acid entry by TcsL caused TcdB-like morphological changes in CHO cells, which suggesting that acid activation may impact substrate recognition profiles for TcsL.

Histamine in lambs with abomasal bloat, haemorrhage and ulcers

The median concentration of histamine in abomasal fluid of lambs with abomasal haemorrhage and/or ulcers (group 2) was significantly (P < 0.05) higher than the concentrations in lambs presenting abomasal bloat (group 1) and in the healthy and the diseased controls. In group 2, there was also a strong correlation (R2 = 0.81) between the histamine concentrations in abomasal tissue and abomasal fluid, although the median value of histamine in the abomasal tissue was not statistically higher in this group than in the others. The urine of lambs in group 2 also had numerically higher median concentration of histamine than the other groups. Five out of eight tested strains of Lactobacillus spp. and one out of two strains of Clostridium sordellii, isolated from abomasal contents of lambs with abomasal disease, were strong producers of histamine. Bacterial production is one possible source for the increased histamine concentrations in lambs suffering from abomasal haemorrhage and/or ulcers.

Effects of iron dextran injections on the incidence of abomasal bloat, clinical pathology and growth rates in lambs

A preliminary study revealed significantly lower serum iron concentrations in lambs that developed abomasal bloat about one week later, than in lambs that did not develop bloat. In a subsequent trial, with 754 naturally reared twin lambs from five flocks, iron dextran injections were found to have a preventive effect on the development of abomasal bloat. Clinical signs of abomasal bloat were observed in the placebo-treated lamb of 16 couples and in the iron-treated lamb of six couples (P<0.05). In three further couples, both lambs developed bloat. The iron-treated group had significantly (P<0.001) better average weight gains, both from birth to summer, and from birth to autumn of approximately 0.5 and 1 kg, respectively. There was a reduction in red blood cell values and iron saturation in the placebo group 14 days after treatment but not in the iron-treated lambs. In one of the flocks, there was a decrease in the cumulative incidence of abomasal bloat from 37 per cent to 3 per cent during the period of four years after measures such as later lambing, earlier turnout and iron injections were introduced.