An investigation into the association between cpb2-encoding Clostridium perfringens type A and diarrhea in neonatal piglets

To investigate the possible role of cpb2-positive type A Clostridium perfringens in neonatal diarrheal illness in pigs, the jejunum and colon of matched normal and diarrheic piglets from 10 farms with a history of neonatal diarrhea were examined grossly and by histopathology, and tested for C. perfringens, for C. perfringens beta2 (CPB2) toxin, as well as for Clostridium difficile toxins, Salmonella, enterotoxigenic Escherichia coli, rotavirus, transmissible gastroenteritis (TGE) virus, and coccidia. Clostridium perfringens isolates were tested using a multiplex real-time polymerase chain reaction (PCR) to determine the presence of cpa, consensus and atypical cpb2, and other virulence-associated genes. The numbers of C. perfringens in the intestinal contents were lower in diarrheic piglets (log₁₀ 5.4 CFU/g) compared with normal piglets (log₁₀ 6.5 CFU/g) (P < 0.05). The consensus cpb2 was present in 93% of isolates in each group, but atypical cpb2 was less common (56% healthy, 32% diarrheic piglets isolates, respectively, P < 0.05). The presence of CPB2 toxin in the intestinal contents of normal and diarrheic piglets did not differ significantly. Clostridium difficile toxins and rotavirus were each detected in 7 of the 21 (33%) diarrheic piglets. Rotavirus, C. difficile toxins, Salmonella, or enterotoxigenic E. coli were concurrently recovered in different combinations in 4 diarrheic piglets. The cause of diarrhea in 8 of the 21 (38%) piglets on 6 farms remained unknown. The etiological diagnosis of diarrhea could not be determined in any of the piglets on 2 of the farms. This study demonstrated that the number of cpb2-positive type A C. perfringens in the intestinal contents was not a useful approach for making a diagnosis of type A C. perfringens enteritis in piglets. Further work is required to confirm whether cpb2-carrying type A C. perfringens have a pathogenic role in enteric infection in neonatal swine.

Outcomes in patients tested for Clostridium difficile toxins

Clostridium difficile testing is shifting from toxin detection to C. difficile detection. Yet, up to 60% of patients with C. difficile by culture test negative for toxins and it is unclear whether they are infected or carriers. We reviewed medical records for 7046 inpatients with a C. difficile toxin test from 2005 to 2009 to determine the duration of diarrhea and rate of complications and mortality among toxin-positive (toxin+) and toxin- patients. Overall, toxin- patients had less severe diarrhea, fewer diarrhea days, and lower mortality (P < 0.001, all comparisons) than toxin+ patients. One toxin- patient (n = 1/6121; 0.02%) was diagnosed with pseudomembranous colitis, but there were no complications such as megacolon or colectomy for fulminant CDI among toxin- patients. These data suggest that C. difficile-attributable complications are rare among patients testing negative for C. difficile toxins. More studies are needed to evaluate the clinical significance of C. difficile detection in toxin- patients.

The successful experimental induction of necrotic enteritis in chickens by Clostridium perfringens: a critical review

Necrotic enteritis (NE) is one of the most important enteric diseases in poultry and is a high cost to the industry worldwide. It is caused by avian-specific, Necrotic Enteritis Beta toxin (NetB)-producing, strains of Clostridium perfringens that also possess in common other virulence-associated genes. In Europe the disease incidence has increased since the ban on in-feed "growth promoting" antibiotics. Because of this, many recent studies of NE have focused on finding different ways to control the disease, and on understanding its pathogenesis. Frustratingly, reproduction of the disease has proven impossible for some researchers. This review describes and discusses factors known to be important in reproducing the disease experimentally, as well as other considerations in reproducing the disease. The critical bacterial factor is the use of virulent, netB-positive, strains; virulence can be enhanced by using tpeL- positive strains and by the use of young rather than old broth cultures to increase toxin expression. Intestinal damaging factors, notably the use of concurrent or preceding coccidial infection, or administration of coccidial vaccines, combined with netB-positive C. perfringens administration, can also be used to induce NE. Nutritional factors, particularly feeding high percentage of cereals containing non-starch polysaccharides (NSP) (wheat, rye, and barley) enhance disease by increasing digesta viscosity, mucus production and bacterial growth. Animal proteins, especially fish meal, enhance C. perfringens proliferation and toxin production. Other factors are discussed that may affect outcome but for which evidence of their importance is lacking. The review compares the different challenge approaches; depending on the aim of particular studies, the different critical factors can be adjusted to affect the severity of the lesions induced. A standardized scoring system is proposed for international adoption based on gross rather than histopathological lesions; if universally adopted this will allow better comparison between studies done by different researchers. Also a scoring system is provided to assist decisions on humane euthanasia of sick birds.

Fatal foodborne Clostridium perfringens illness at a state psychiatric hospital--Louisiana, 2010

Clostridium perfringens, the third most common cause of foodborne illness in the United States (1), most often causes a self-limited, diarrheal disease lasting 12-24 hours. Fatalities are very rare, occurring in <0.03% of cases (1). Death usually is caused by dehydration and occurs among the very young, the very old, and persons debilitated by illness (2). On May 7, 2010, 42 residents and 12 staff members at a Louisiana state psychiatric hospital experienced vomiting, abdominal cramps, and diarrhea. Within 24 hours, three patients had died. The three fatalities occurred among patients aged 41-61 years who were receiving medications that had anti-intestinal motility side effects. For two of three decedents, the cause of death found on postmortem examination was necrotizing colitis. Investigation by the Louisiana Office of Public Health (OPH) and CDC found that eating chicken served at dinner on May 6 was associated with illness. The chicken was cooked approximately 24 hours before serving and not cooled in accordance with hospital guidelines. C. perfringens enterotoxin (CPE) was detected in 20 of 23 stool specimens from ill residents and staff members. Genetic testing of C. perfringens toxins isolated from chicken and stool specimens was carried out to determine which of the two strains responsible for C. perfringens foodborne illness was present. The specimens tested negative for the beta-toxin gene, excluding C. perfringens type C as the etiologic agent and implicating C. perfringens type A. This outbreak underscores the need for strict food preparation guidelines at psychiatric inpatient facilities and the potential risk for adverse outcomes among any patients with impaired intestinal motility caused by medications, disease, and extremes of age when exposed to C. perfringens enterotoxin.

Emphysematous cholecystitis complicating liver abscess due to Clostridium baratii infection

Clostridium baratii bacteremia is a rare but severe anaerobic infection. Its major clinical features are neurological presentation, and significant risk factors include hemodialysis, intestinal disease or malignancy. We describe a case of emphysematous cholecystitis complicated by a liver abscess due to C baratii infection in a healthy adult without neurological manifestation.

Necrotizing duodenitis caused by Clostridium perfringens type A in a Japanese young man

A 21-year-old Japanese man with a history of marked body weight loss over a short period of time died of necrotizing duodenitis caused by Clostridium perfringens (C. perfringens) type A. C. perfringens type A is considered to usually cause self-limiting gastroenteritis. Necrotizing enteritis sometimes occurs due to C. perfringens in developing countries; however, it is primarily caused by the type C strain and its site of onset is typically the jejunum or ileum. This is a rare case of necrotizing duodenitis caused by C. perfringens type A in a Japanese young man. Physicians need to be more aware of this emerging fatal disease in developed countries.

Clostridium difficile infection rates and spectrum of disease among peripartum women at one hospital from 2003 to 2007 with molecular typing analysis of recovered Clostridium difficile isolates

BACKGROUND

Peripartum women are at risk for Clostridium difficile infection (CDI), but the risk magnitude and clinical disease spectrum are unknown. We determined the incidence and clinical features of CDI in peripartum women in the Loyola University Medical Center system and describe typing of C difficile isolates by restriction endonuclease analysis (REA).

METHODS

A retrospective chart review of peripartum CDI from 2003 to 2007 was performed after identifying patients from the clinical laboratory log of positive C difficile toxin assays. Available stool samples were cultured and isolates typed using REA.

RESULTS

We found 12 CDI cases over 5 years for an incidence of 0.7 cases/1,000 obstetrics ward admissions. Prior antibiotic use was documented in 11 (92%) cases, and 8 (67%) were health care facility associated. The rate of CDI following cesarean section was 2.2 per 1,000 live births compared with 0.2 per 1,000 following vaginal delivery (relative risk, 11.6; 95% confidence interval: 1.39-96.23). Typing revealed 4 different REA strain groups; 6 of the 7 REA types were toxin variants.

CONCLUSION

CDI in peripartum women is similar to CDI in other groups except for age. CDI was caused by multiple REA types. Cesarean section may be a particular risk for CDI that develops in the postpartum period.

The changing epidemiology of Clostridium difficile infections

The epidemiology of Clostridium difficile infection (CDI) has changed dramatically during this millennium. Infection rates have increased markedly in most countries with detailed surveillance data. There have been clear changes in the clinical presentation, response to treatment, and outcome of CDI. These changes have been driven to a major degree by the emergence and epidemic spread of a novel strain, known as PCR ribotype 027 (sometimes referred to as BI/NAP1/027). We review the evidence for the changing epidemiology, clinical virulence and outcome of treatment of CDI, and the similarities and differences between data from various countries and continents. Community-acquired CDI has also emerged, although the evidence for this as a distinct new entity is less clear. There are new data on the etiology of and potential risk factors for CDI; controversial issues include specific antimicrobial agents, gastric acid suppressants, potential animal and food sources of C. difficile, and the effect of the use of alcohol-based hand hygiene agents.

Clinical spectrum & pathogenesis of Clostridium difficile associated diseases

Clostridium difficile is the major aetiological agent of antibiotic associated diarrhoea and colitis. The majority of hospitalized patients infected by C. difficile are asymptomatic carriers who serve as silent reservoirs for continued C. difficile contamination of the hospital environment. C. difficile associated disease (CDAD) is a serious condition with mortality up to 25 per cent in frail elderly people. C. difficile infection may present itself in several forms with both colonic and extracolonic manifestations. Several factors are involved in determining whether or not a patient develops C. difficile infection. These include factors related to the pathogen as well as the host. Transmission of C. difficile can be endogenous or exogenous. Colonization of the pathogen occurs when the gut flora gets disrupted due to various factors. The main virulence factors for CDAD are the two potent toxins: toxin A and toxin B which share 63 per cent of amino acid sequence homology and act on small guanosine triphosphate binding proteins. The emergence of the global hypervirulent C. difficile strain has been a cause of concern. Diagnosis of CDAD infection can be done by detection of C. difficile toxin in the stool specimen. Vancomycin is the drug of choice for severely ill patient, whereas metronidazole can be used for mild to moderately ill patients. Clinical spectrum, the factors precipitating CDAD, pathogenesis, diagnostic assay and treatment of the disease are reviewed.

[Post-mortal detection of clostridia--putrefaction or infection?]

Clostridia are often found in the heart blood and organs of corpses showing putrefactive changes, and it can sometimes be difficult to distinguish between an ante-mortem infection caused by these gram-positive, anaerobic, spore-forming bacteria and post-mortal putrefactive changes. Microbiological tests ordered by the Institute of Legal Medicine of the Hanover Medical School following autopsy between July 2006 and June 2009 were analyzed retrospectively. In all, 50 bacteriological analyses were performed. In 2006, no clostridia were detected, whereas in 2007 the bacteria were demonstrated in 3 (18.8%), in 2008 in 4 (23.5%) and in 2009 in 5 (33.3%) cases. In 50% of the cases, there had been an ante-mortal clostridia infection. The remaining 50% were due to post-mortem transmigration of clostridia species. The results of this study underline the importance of additional post-mortem bacteriological and histological investigations.

Innate immune recognition of, and response to, Clostridium sordellii

Clostridium sordellii, an anaerobic pathogen, has recently been associated with rapidly fatal infections following medically induced abortions and injecting drug use. Patients with C. sordellii infection display few signs of inflammation such as fever, or redness and pain at the site of infection. We hypothesized that this could be due to reduced recognition of the organism by Toll-like receptors (TLRs) of the innate immune system. An ELAM-NF-kappaB luciferase reporter system in TLR-transfected HEK cells was used to measure TLR-dependent recognition of washed, heat-killed C. sordellii and other pathogenic clostridial species. Results demonstrated that all clostridia were well recognized by TLR2 alone and that responses were greatest when TLR2 was co-expressed with TLR6. Further, isolated human monocytes produced the pro-inflammatory cytokine TNFalpha and the immunoregulator IL-10 in response to C. sordellii. In addition, C. sordellii-stimulated monocytes produced 30% less TNFalpha following treatment with an anti-TLR2 blocking antibody. These data demonstrate that innate immune recognition of, and response to, cell-associated components of C. sordellii and other clostridial pathogens are mediated by TLR2 in combination with TLR6. We conclude that the characteristic absence of inflammatory signs and symptoms in C. sordellii infection is not related to inadequate immune detection of the organism, but rather is attributable to a species-specific immune system dysfunction that remains to be elucidated.

NetB, a new toxin that is associated with avian necrotic enteritis caused by Clostridium perfringens

For over 30 years a phospholipase C enzyme called alpha-toxin was thought to be the key virulence factor in necrotic enteritis caused by Clostridium perfringens. However, using a gene knockout mutant we have recently shown that alpha-toxin is not essential for pathogenesis. We have now discovered a key virulence determinant. A novel toxin (NetB) was identified in a C. perfringens strain isolated from a chicken suffering from necrotic enteritis (NE). The toxin displayed limited amino acid sequence similarity to several pore forming toxins including beta-toxin from C. perfringens (38% identity) and alpha-toxin from Staphylococcus aureus (31% identity). NetB was only identified in C. perfringens type A strains isolated from chickens suffering NE. Both purified native NetB and recombinant NetB displayed cytotoxic activity against the chicken leghorn male hepatoma cell line LMH; inducing cell rounding and lysis. To determine the role of NetB in NE a netB mutant of a virulent C. perfringens chicken isolate was constructed by homologous recombination, and its virulence assessed in a chicken disease model. The netB mutant was unable to cause disease whereas the wild-type parent strain and the netB mutant complemented with a wild-type netB gene caused significant levels of NE. These data show unequivocally that in this isolate a functional NetB toxin is critical for the ability of C. perfringens to cause NE in chickens. This novel toxin is the first definitive virulence factor to be identified in avian C. perfringens strains capable of causing NE. Furthermore, the netB mutant is the first rationally attenuated strain obtained in an NE-causing isolate of C. perfringens; as such it has considerable vaccine potential.

Clostridium perfringens can cause gas gangrene and food poisoning in humans and causes several enterotoxemic diseases in animals including avian necrotic enteritis. This disease affects all chicken producing countries worldwide and is a considerable burden on the commercial chicken production industry. Until recently alpha-toxin was thought to be the major virulence factor involved in necrotic enteritis. However, by using an alpha-toxin null mutant it has been demonstrated that this toxin is not essential for disease. This paper details the identification and characterisation of a novel toxin, NetB, and provides evidence that the protein is an essential factor in causing necrotic enteritis in chickens. NetB has limited protein sequence identity to the beta-toxin of C. perfringens, which causes mucosal necrosis of the small intestine in humans and animals. We demonstrate that NetB null mutants can no longer cause disease in chickens, whereas both the wild-type and mutant complemented with a wild-type netB gene caused significant levels of necrotic enteritis. The identification of this important toxin advances our understanding of the pathogenesis of the disease and opens significant opportunities for the development of novel vaccines against necrotic enteritis in poultry.

Clinical severity of Clostridium difficile PCR ribotype 027: a case-case study

BACKGROUND

Clostridium difficile is a leading infectious cause of health care associated diarrhoea. Several industrialised countries have reported increased C. difficile infections and outbreaks, which have been attributed to the emergent PCR ribotype 027 strain.

METHODS AND FINDINGS

We conducted a case-case study to compare severity of C. difficile disease for patients with 027 versus non-027 ribotypes. We retrospectively collected clinical information about 123/136 patients with C. difficile infections admitted to hospitals in the East of England region in 2006 and from whom stool isolates were cultured and ribotyped as part of an earlier national survey. We defined severe C. difficile disease as having one or more of shock, paralytic ileus, pseudo membranous colitis or toxic megacolon. Patient median age was 83 years old (range 3 to 98, interquartile range 75 to 89), 86% were prescribed antibiotics in the eight weeks before illness onset, 41% had ribotype 027 and 30-day all cause mortality during hospital admission was 21%. Severe disease occurred in 24% (95%CI 13% to 37%) and 17% (95%CI 9% to 27%) of patients with PCR ribotype 027 and non-027 ribotypes respectively. In a multivariable model, ribotype 027 was not associated with severe disease after adjusting for sex, discharge from hospital prior to 60 days of current admission, gastroenteritis on admission, number of initiator antibiotics for C. difficile disease, and hospital where the patient was admitted.

CONCLUSIONS

Our study found no evidence to support previous assertions that ribotype 027 is more virulent than other PCR ribotypes. This finding raises questions about the contribution of this strain to the recent increase in C. difficile disease throughout North America and Europe.

Clostridial sacroiliitis in a patient with fecal incontinence: a case report and review of the literature

INTRODUCTION

Image-guided sacroiliac joint injections are frequently employed for both diagnostic and therapeutic relief of low back pain.

CASE REPORT

An 83-year-old male with chronic lumbrosacral pain previously responsive to right sacroliac joint injections presented for repeat injection. His medical history included Parkinsonism and stool incontinence. Forty-two hours after the injection, he developed fever, dyspnea, and crepitus on the right buttock and thigh. Surgical debridement was recommended, but the family wished for comfort care only. The patient died hours later. The autopsy revealed Gram positive bacilli consistent with Clostridial myonecrosis.

DISCUSSION

Pyogenic sacroiliitis is rare and usually occurs in the setting of trauma, drug abuse, or extraspinal infections. Joint infections with Clostridium have been reported after traumatic events including puncture, surgery, and abrasions. Clostridium spores are resistant to chemical preparations used for skin sterilization and require high heat for destruction. Possible practice guidelines with patients that are stool incontinent include mechanical wash prior to sterile preparation and placement of an occlusive sterile dressing after injection to prevent stool contamination of the needle puncture site. As with all rare complications, large scale studies are needed to better identify risk factors to formulate practice management strategies.

Necrotic enteritis-producing strains of Clostridium perfringens displace non-necrotic enteritis strains from the gut of chicks

We inoculated broiler chicks with mixtures of Clostridium perfringens strains to investigate the single strain dominance observed in natural cases of necrotic enteritis (NE) [Nauerby, B., Pedersen, K., Madsen, M., 2003. Analysis by pulsed-field gel electrophoresis of the genetic diversity among Clostridium perfringens isolates from chickens. Vet. Microbiol. 94, 257-266]. Pre-inoculation bacteriologic culture of chick intestines yielded up to six pulsed-field gel electrophoresis (PFGE) types of C. perfringens. Birds developed typical NE lesions in response to administration (2x per day for 4 days) of a combined inoculum comprising one NE strain (JGS4143, PFGE pattern 8) and four non-NE strains (from piglet necrotizing enteritis, chicken normal flora, human gas gangrene, and bovine neonatal enteritis). After inoculation commenced, only the NE strain was recovered through the first post-inoculation day, in spite of intense efforts to recover pre-challenge flora strains and the other challenge strains. Thereafter, pre-inoculation and previously undetected PFGE types were found, and JGS4143 became undetectable. Birds inoculated simultaneously with five NE strains (from disease in chickens or turkeys, and including JGS4143) also developed lesions, but again only JGS4143 was recovered through the 1st day post-challenge. At that time, birds began to be repopulated with pre-challenge PFGE types. Two NE strains (JGS4143 and JGS4064) produced bacteriocins, which inhibited each other and normal flora strains (n=17), while normal flora strains inhibited neither NE strains nor each other. Thus, it appears that naturally occurring dominance of the gut by NE strains can be reproduced experimentally. Bacteriocins directed against normal flora could possibly provide the necessary advantage, although inhibition of one NE strain by another suggests that other factors may be partially or completely responsible for the dominance.

Quantification of gut lesions in a subclinical necrotic enteritis model

Currently Clostridium perfringens-induced necrotic enteritis is a major problem in broiler flocks. In the present study, broilers were inoculated with a combination of Eimeria maxima or overdose coccidial vaccine (one inoculation) with C. perfringens (repeated inoculations). Single C. perfringens, E. maxima or an overdose of live coccidial vaccine inoculations did not result in grossly visible necrotic gut lesions, while combined inoculation resulted in typical necrotic lesions at approximately 4 days after inoculations with C. perfringens in approximately one-half of the inoculated animals. Semi-quantitative histological lesion scoring was done to evaluate gut damage in gut sections of animals in which no gross necrotic lesions were detected. This included scoring of hyperaemia, haemorrhages, the amount of red blood cells and protein precipitate in the lumen, villus fusion and epithelial defects. The villus length and the villus length/crypt depth ratio were also analysed. This approach proved to be discriminative between single E. maxima infection, overdose of coccidial vaccine or C. perfringens inoculations and the non-inoculated control group, and between the double-inoculated and single-inoculated groups. In general, the highest histological scores for gut lesions were observed in the double-inoculated groups, but the single-inoculated groups had higher scores than the control group. It was concluded that oral inoculation of broilers with an overdose of live coccidial vaccine in combination with multiple oral C. perfringens inoculations is a suitable model for necrotic enteritis without inducing mortality of the animals. C. perfringens and Eimeria act synergistically in inducing grossly visible gut damage.

Leger J, Puschner B, Fisher DJ, McClane BA, Uzal FA. Necrotizing enterocolitis and death in a goat kid associated with enterotoxin (CPE)-producing Clostridium perfringens type A

A goat kid died after being depressed for several days. No significant gross abnormalities were observed at postmortem examination, while histopathological analysis revealed diffuse necrotizing enterocolitis. Isolation of Clostridium perfringens type A secreting enterotoxin (CPE) and presence of CPE in the small intestine suggest that CPE contributed to the death of this kid.

Enteritis necroticans 'pigbel' in a Japanese diabetic adult

Enteritis necroticans 'pigbel' is caused by Clostridium perfringens type C but has rarely been reported in developed countries. A 50-year-old Japanese man with untreated diabetes mellitus (DM) presented with diarrhea and abdominal pain. Intraoperative endoscopic and macroscopic examination disclosed segmental annular mucosal lesions characteristic of clostridial enteritis. Clostridial infection type C was verified on pathological, and immunohistochemical analysis. Although rare, the disease is likely to be underdiagnosed. Hence, the pathology and immunohistochemistry of segmental enteritis with annular mucosal lesions should be examined to establish a diagnosis of enteritis necroticans even in mildly affected patients, and especially those with DM.

Massive intravascular hemolysis in a patient infected by a Clostridium perfringens

Clostridium perfringens infection is a very rare cause of massive intravascular hemolysis, but it should always be kept in mind, since only early treatment can rescue patients from an otherwise rapidly fatal outcome. We report a case of a 78-year-old diabetic male who was admitted complaining of general fatigue, dark red urine, and vomiting. His blood revealed massive hemolysis. Computer tomography demonstrated huge liver abscess in the right lobe of the liver. About 1 h after admission, he suddenly fell into a critical condition. He died 3 h after admission in spite of intensive care and resuscitation. Clostridium perfringens was detected from the blood taken before death and from liver abscess by biopsy after death. We concluded that this patient died of acute massive intravascular hemolysis in septicemia caused by Clostridium perfringens infection.