Soft tissue infections caused by spore-forming bacteria in injecting drug users in the United Kingdom.

From 2000 to May 2004 there has been a marked increase in illness resulting from spore-forming bacteria in injecting heroin users in the United Kingdom. Clostridium novyi caused 63 cases of severe illness in 2000 and seven further cases from 2001. Wound botulism first occurred in 2000 (six cases) with 51 further cases to March 2004. Tetanus occurred in 20 cases between late 2003 and March 2004. Infections with C. histolyticum (nine cases), C. sordellii (one case) and Bacillus cereus (one case) were also reported. The reasons for the increase in illness are unclear. The major risk factor was skin- or muscle-popping. The problem appears to be here to stay. This review describes the causative organisms, pathogenesis, clinical presentation, epidemiology and treatment of cases. Clinical vigilance and a high standard of anaerobic microbiology are essential. Clinicians and laboratories must report such cases (or likely cases) rapidly so that clusters can be rapidly identified, in order to control disease. Prevention relies on tetanus immunization.

A case of infant botulism with a possible link to infant formula milk powder: evidence for the presence of more than one strain of Clostridium botulinum in clinical specimens and food.

Infant botulism was confirmed in a 5-month-old female by both isolation of Clostridium botulinum type B and by detection of type B botulinum neurotoxin in rectal washout and faeces. DNA fingerprinting of nine isolates from faeces yielded two different amplified-fragment length polymorphism (AFLP) patterns. C. botulinum was isolated from two of 14 food and drink items from the patient's home: C. botulinum type A was recovered from an opened container of dried rice pudding and C. botulinum type B from opened infant formula milk powder. Ten C. botulinum type B isolates from the opened infant formula yielded four AFLP patterns, two of which were indistinguishable from the clinical isolates. Fifteen unopened foods were tested and C. botulinum type B of a unique AFLP pattern was recovered from one unopened infant formula of the same batch as the opened container. It is suggested that multiple C. botulinum were present in both food and the intestine during infant botulism.

Detection of Clostridium difficile cytotoxin and Clostridium perfringens enterotoxin in cases of diarrhoea in the community.

Faecal specimens from 843 cases of diarrhoea in the community were tested for the presence of Clostridium difficile cytotoxin and Clostridium perfringens enterotoxin. C. difficile cytotoxin was detected in faecal specimens from 0.6 % of cases aged at least 2 years by using a Vero cell assay. Factors associated with detection of C. difficile cytotoxin were antibiotic therapy, age over 60 years and living in a home with other elderly people. Three methods were used for the detection of C. perfringens enterotoxin: a Vero cell assay, a commercial (TechLab) enzyme immunoassay (EIA) and an in-house EIA. The lower level of detection of pure C. perfringens enterotoxin in buffer was 0.01 micro g ml(-1) by the TechLab EIA and 1.0 micro g ml(-1) by the Vero cell assay. C. perfringens enterotoxin was detected by using the TechLab EIA in faecal specimens from 2.5 % of cases. This commercial EIA was less sensitive than the in-house EIA, detecting only 31 % of positive cases, but was specific and could be used for outbreak investigation by routine diagnostic laboratories. Age over 60 years was a factor associated with C. perfringens enterotoxin detection; this age group may be targeted for testing.

Isolation and identification of Clostridium spp. from infections associated with the injection of drugs: experiences of a microbiological investigation team.

Pathogenic species of the genus Clostridium may contaminate the materials used in the injection of drugs and under the right conditions may cause serious or life-threatening disease. C. novyi type A was implicated in an outbreak of severe infection with high mortality in injecting drug users who injected heroin extravascularly. The isolation of such highly oxygen-sensitive clostridia from clinical material may require adherence to enhanced methods and, once isolated, commercially available anaerobe identification kits alone may not give an accurate identification. Additional phenotypic tests that are useful in recognising the main pathogenic species are described. Differentiation of C. novyi type A from C. botulinum type C in reference laboratories was based on 16S rDNA sequence data and specific neutralisation of cytopathic effects in tissue culture.

Amplified fragment length polymorphism (AFLP) analysis of Clostridium novyi, C. perfringens and Bacillus cereus isolated from injecting drug users during 2000.

As part of the follow-up investigations associated with an outbreak of severe illness and death among illegal injecting drug users during 2000, 43 cultures of Clostridium novyi type A, 40 C. perfringens type A and 6 isolates of Bacillus cereus were characterised by amplified fragment length polymorphism (AFLP) analysis. Among the 43 C. novyi isolates, 23 different AFLP profiles were detected. The same AFLP profile was detected in isolates from 18 drug users investigated during 2000 from Scotland, England, the Republic of Ireland and Norway and a wound from a patient in 2000 who was not identified as a drug user. Unique AFLP profiles were obtained from four drug users from England and the Republic of Ireland, 10 historical isolates from culture collections, an isolate from food (1989) and three isolates from wounds (1995, 1991, 1988). The 40 C. perfringens isolates were from 13 drug users, the contents of one syringe and two samples of heroin. Sixteen AFLP types of C. perfringens were distinguished and there was little evidence for commonality among the isolates. The AFLP types of C. perfringens from heroin differed and were unique. Six isolates of B. cereus were from four drug users and two samples of heroin. Four different AFLP patterns were distinguished. Three AFLP types were isolated from four drug users. B. cereus isolates from an aspirate and a heroin sample collected from the same drug user were identical, and were also indistinguishable from an isolate from a groin infection in a second drug user. The AFLP type of the isolate from a second and unrelated heroin sample was unique. The AFLP results showed no or very limited evidence for commonality between the different isolates of B. cereus and C. perfringens. In marked contrast, the C. novyi isolates from the majority of the drug users during 2000 were homogeneous, suggesting a common source or clonal selection of a C. novyi type, or both, which either had an adaptive advantage in spore germination, survival or growth following the drug preparation and the injection procedure, or produced a more severe clinical presentation.

Suspected botulism in dairy cows and its implications for the safety of human food.

A large outbreak of suspected botulism occurred on a dairy farm. The affected animals were listless and showed signs ranging from hindlimb unsteadiness to lateral recumbency, although the most common presentation was sternal recumbency with an apparent hindlimb weakness when stimulated to rise. Postmortem examinations revealed no conclusive gross pathology or histopathology. The affected cattle were found to have neutrophilia and hyperglycaemia with no other consistent haematological or biochemical abnormalities. The combination of clinical signs, disease epidemiology and the ruling out of other differential diagnoses strongly supported a diagnosis of unconfirmed botulism; however, the source of toxin was not demonstrated. Botulism is a severe disease in human beings and there are uncertainties about the pharmacokinetics and pharmacodynamics of Clostridium botulinum toxins. In such circumstances, a precautionary approach to food safety is essential. Restrictions were placed on the movement of livestock and sale of milk from the farm premises until 14 days after the onset of the last clinical case.

General outbreaks of infectious intestinal disease associated with fish and shellfish, England and Wales, 1992-1999.

Between 1992 and 1999 1425 foodborne general outbreaks of Infectious Intestinal Disease (IID) were reported to the PHLS Communicable Disease Surveillance Centre. Of these, 148 (10%) were associated with the consumption of fish and shellfish. Three main aetiologies were identified. Outbreaks associated with fish (47%) occurred more frequently in the summer months, and were linked with Scombrotoxic fish poisoning caused by the consumption of tuna that was improperly stored. Outbreaks associated with molluscs (36%) were associated with the consumption of oysters contaminated with viral pathogens, particularly in February. Outbreaks associated with the consumption of crustaceans (11%) often involved eating prawns that contained either salmonellas or viral pathogens. The maintenance of microbial quality from prior to capture/harvesting until the moment of consumption, based on a Hazard Analysis and Critical Control Point style approach, is essential if gastrointestinal illness associated with such produce is to be avoided.

Amplified fragment length polymorphism (AFLP) analysis of Clostridium perfringens for epidemiological typing.

Thirty-five Clostridium perfringens isolates from patients and foods implicated in seven outbreaks of suspected Cl. perfringens food poisoning together with five unrelated incidents were analysed by serotyping and amplified fragment length polymorphism (AFLP). Despite minor band differences, AFLP was found to be highly reproducible and 16 different profiles (each unique to the 12 incidents) were recognised. The results from both serotyping and AFLP analysis identified exactly the same groups of related cultures. It is concluded that AFLP can provide a rapid, sensitive and reproducible method for the typing of Cl. perfringens for outbreak investigation.

A study of infectious intestinal disease in England: microbiological findings in cases and controls.

A study was undertaken to identify the microorganisms and toxins in stool specimens associated with infectious intestinal disease (IID) among cases in the community and presenting to general practitioners (GPs) and in asymptomatic controls. Population based cohorts were recruited from practice lists in 70 practices and followed for 26 weeks (cohort component). Seven hundred and sixty-one cases of IID identified from the cohorts, 2893 cases who presented to GPs in 34 of the practices (GP component), and age/sex matched control subjects (555 and 2264, respectively) submitted stool specimens by post for comprehensive microbiological examination. Campylobacter spp (12.2% of stools tested), rotavirus group A (7.7%), and small round structured virus (SRSV) (6.5%) were the organisms most commonly detected in the GP component. SRSV was identified in 7.0% of cases in the community cohort. No target microorganisms or toxins were identified in 45.1% and 63.1% of cases in the two components. Aeromonas spp, Yersinia spp, and some enterovirulent groups of Escherichia coli were detected as frequently in controls as in cases. The higher frequency of detection of campylobacter, salmonella, and rotavirus among cases who presented to GPs than among those in the community suggests that those pathogens cause more severe illness. No enteropathogens were detected from a large proportion of cases although comprehensive standard methods were used to seek them.

Fatal Clostridium perfringens sepsis from a pooled platelet transfusion.

A male patient with acute myeloid leukaemia received a pooled platelet preparation prepared by Optipress system on the last day of its shelf life. The patient collapsed after two-thirds of the contents had been transfused. Clostridium perfringens was isolated from the platelet bag within 18 h of the acute event. Metronidazole, gentamicin and Clostridium antiserum were then administered in addition to the broad spectrum antibiotics started previously. However, the patient died 4 days after the platelets were transfused. The cause of death was given as cardiovascular shock, entirely compatible with an overwhelming bacteraemic and septic episode. A coroner's verdict of accidental death due to transfusion of a contaminated unit of platelets was recorded. On subsequent investigation Cl. perfringens type A serotype PS68,PS80 (identical to that found in the platelet bag) was cultured from the venepuncture site of the arm of one of the donors who contributed towards the platelet pool. The donor had two young children and frequently changed nappies. Faecal contamination of the venepuncture site was the suspected source for the transmission of Cl. perfringens, an organism commonly found in the soil and intestinal tract of humans. This case dramatically highlights the consequences of transfusing a bacterially contaminated unit. It is vital that such incidents are investigated and reported so that the extent of transfusion-associated bacterial transmission can be monitored and preventative measures taken if possible.

Evaluation of the use of the bioMerieux Rapid ID32 A for the identification of Clostridium botulinum.

The neurotoxins produced by Clostridium botulinum are amongst the most potent known to man. Toxin production is detected by a mouse bioassay, which requires several days for a result and is not acceptable for routine use unless there is a high level of suspicion. The Rapid ID32 A kit produced by bioMerieux gives an identification of an isolate within 4 h. The aim of this study was to examine the efficiency of the identification of Cl. botulinum using the Rapid ID32 A. Forty-two strains of Cl. botulinum, one strain each of botulinum toxin-producing Cl. butyricum and Cl. baratii, and four strains of Cl. sporogenes, were tested. One strain of Group I Cl. botulinum gave a presumptive identification of Group II Cl. botulinum, six strains of Cl. botulinum were identified as 50-98% Cl. botulinum in some tests, and 17 strains of Cl. botulinum were identified as < 50% Cl. botulinum. Thirteen strains of Cl. botulinum were identified as > 99% Cl. sporogenes or 86% Cl. histolyticum, and five strains gave a combination of these results. All strains of Cl. sporogenes were correctly identified. These results show that some strains of Cl. botulinum may not be correctly identified using the Rapid ID32A.

Enterotoxigenic Clostridium perfringens as a cause of sporadic cases of diarrhoea.

The purpose of this study was to investigate the incidence of cases of sporadic diarrhoea associated with enterotoxigenic Clostridium perfringens. Cases were identified by detection of C. perfringens enterotoxin with the Oxoid RPLA kit, with confirmation by ELISA, in faecal specimens from isolated incidents of diarrhoea and from which no other enteropathogen had been isolated. In a 2-month study, 65 (18%) of 370 specimens were enterotoxin positive. There was no predominant age group or sex in the enterotoxin-positive group, but higher proportion (79%) was resident in the community than were enterotoxin-negative cases (34%). Only four of the 65 enterotoxin-positive patients had received antibiotic therapy. Spore counts in most enterotoxin-positive patients were < 10(5)/g, indicating that detection of high numbers of C. perfringens is not useful in determining the aetiology of sporadic diarrhoea. Diagnosis should be confirmed by the detection of enterotoxin, but further work is required to assess whether an acceptable accuracy is obtained with the RPLA kit or whether ELISA is needed in all cases.

Outbreaks of food-poisoning associated with lecithinase-negative Clostridium perfringens.

Clostridium perfringens type A is a common cause of food-poisoning. Production of lecithinase (alpha toxin) is frequently used to identify the organism. Details of 10 outbreaks of food-poisoning caused by lecithinase-negative C. perfringens are reported here.

Application of pyrolysis mass spectrometry to the investigation of outbreaks of food poisoning and non-gastrointestinal infection associated with Bacillus species and Clostridium perfringens.

Eighteen isolates of Bacillus species and 15 of Clostridium perfringens, all of which had been associated with outbreaks of either food poisoning or non-gastrointestinal infection (NGI), were examined for relatedness by pyrolysis mass spectrometry (PyMS). The PyMS-analysis correctly clustered all the groups of epidemiologically related isolates of both genera, and distinguished all the single, epidemiologically unrelated isolates of the same species. PyMS is a simple, rapid and inexpensive technique which can provide useful and accurate inter-strain comparisons within both the Bacillus and Clostridium genera in complete accord with conventional serological typing results.

The value of serum IgG titres against Pseudomonas aeruginosa in the management of early pseudomonal infection in cystic fibrosis.

We report the results of a clinical trial. Patients enrolled had serum IgG titres against Pseudomonas aeruginosa above the control range. Assignment to the observation or treatment group was by minimisation. Significant signs or symptoms in any patient prompted antipseudomonal treatment. In addition, the treatment group received antipseudomonal treatment at intervals of four months until the serum IgG titre returned to the control range. P aeruginosa was isolated intermittently from patients in the main trial. Nineteen patients were enrolled (12 observation, seven treatment). After one year in the trial changes in parameters studied, including forced expiratory volume in one second, IgG titre, serum IgG concentrations, and frequency of P aeruginosa isolation had improved in the treated group and worsened in the observation group.