Delftia acidovorans as an Unusual Causative Organism in Line-Related Sepsis.

The problem of line-related sepsis in patients undergoing chemotherapy for malignant disease remains a major problem in cancer-care even into the third millennium. We report a highly unusual pathogen which represented both a diagnostic and treatment challenge and highlights important issues around patient education as well as laboratory capability in the identification of causative organisms in line-related infections to facilitate clinical management.

The phenotypic relationship of Neisseria polysaccharea to commensal and pathogenic Neisseria spp.

Eight of 22 non-capsulate strains of Neisseria meningitidis previously isolated from primary school children were re-identified as N. polysaccharea by aminopeptidase reactions and polysaccharide production. N. polysaccharea was not identified amongst 91 non-capsulate strains of N. meningitidis isolated from adults attending the Genito-urinary Medicine clinic, Westminster Hospital, London. The biochemical reactions of N. polysaccharea strains were similar to those of N. lactamica and N. gonorrhoeae, but N. polysaccharea could be distinguished from these organisms by examination of beta-galactosidase activity, carbohydrate reactions and polysaccharide production. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed closer similarity of N. polysaccharea to N. lactamica than to the pathogenic Neisseria spp. An additional finding was variation in the position of one of the major proteins of N. lactamica in the 34-39-Kda region.

Detection of antibodies to common antigens of pathogenic and commensal Neisseria species.

Sera from 29 children and six adults were used to investigate the nature of antigenic cross-reactivity between Neisseria polysaccharea, N. lactamica and N. meningitidis B,15P1.16 by immunoblotting. Major common antigens of 68-70 Kda, 60-65 Kda and 15-20 Kda were detected. Antibody directed against them uniformly decreased after absorption of the sera with the three different Neisseria species. Antigens of 55 Kda and 35 Kda specific to N. meningitidis, and one of 43 Kda specific to N. lactamica, were also demonstrated. Antibody against all antigens was more prevalent in bactericidal than in non-bactericidal sera, although these differences were statistically not significant. Differences in antibody prevalence between carriers of Neisseria spp. and non-carriers of these organisms were even less marked. Examination of sera by whole-cell enzyme-linked immunosorbent assay against N. meningitidis B,15P1.16 and N. lactamica gave an absorbance ratio of 1:1. Only four sera from children showed no reactivity against the meningococcal strain. These common antigens are likely to be important in vaccine development.

An outbreak of Serratia marcescens infection following urodynamic studies.

Serratia marcescens was isolated from the urine of five patients, two of whom subsequently developed septicaemia with other Gram-negative bacilli. Four of the five patients had undergone urodynamic investigation. An inadequately sterilized re-usable rectal balloon was identified as the source of infection.

A trial of mezlocillin versus cefuroxime with or without metronidazole for the prevention of wound sepsis after biliary and gastrointestinal surgery.

A randomized controlled trial was undertaken to compare the role of mezlocillin, as the sole prophylactic agent, with a combination of cefuroxime and metronidazole in patients undergoing biliary and gastrointestinal surgery. No difference in wound infection rates was seen in patients following appendicectomy, biliary or gastro-oesophageal surgery. A significantly higher wound infection rate was seen in patients undergoing colorectal surgery who received mezlocillin alone (30.2%) compared with those receiving cefuroxime and metronidazole (11.5%): this rate was similar to that of historical placebo controls in other units. The wound infections seen in patients receiving mezlocillin alone were polymicrobial involving organisms of faecal origin, including non-sporing anaerobes which were predominantly sensitive to mezlocillin. Infections due to Staphylococcus aureus, resistant to mezlocillin, were more frequent in patients receiving mezlocillin and usually secondary in nature. We conclude that mezlocillin may be an effective sole prophylactic agent in appendicectomy but not in colorectal surgery; the possible reasons for failure to adequately prevent infection, following colorectal surgery, are discussed.

Distribution of Borrelia burgdorferi s.l. spirochaete DNA in British ticks (Argasidae and Ixodidae) since the 19th century, assessed by PCR.

The distribution of Borrelia burgdorferi sensu lato, the Lyme borreliosis agent, was surveyed in British ticks in the collection of the Natural History Museum, London. Alcohol-preserved specimens of eight species of ticks known to attack humans were studied: Ixodes ricinus, I. hexagonus, I. uriae, I. trianguliceps, Dermacentor reticulatus, Haemaphysalis punctata, Rhipicephalus sanguineus and Argas vespertilionis. The sample comprised all life stages and originated from a wide range of host species, collection dates (1896-1994) and geographical localities in England, Scotland and Wales. Borrelia burgdorferi s.l. DNA, detected by a polymerase chain reaction that targeted the outer surface protein A gene, was found in all eight species. The overall proportion of PCR-positive specimens ranged from 7.8% for I. hexagonus (mostly from mustelids and hedgehogs) to 98.3% for I. uriae (mostly from seabirds). Borrelia burgdorferi s.l. DNA was found for the first time in the bat parasite A. vespertilionis (85.3%). The spirochaete is newly recorded in British populations of I. trianguliceps (97.4%, mostly from voles, mice and shrews), D. reticulatus (12.5% from dog and man) and R. sanguineus (30% from dogs and human dwellings). Of the four tick species with larvae available for testing, examples of I. ricinus, I. uriae and A. vespertilionis were PCR positive, as were significantly more nymphs than adults of I. ricinus, I. hexagonus and A. vespertilionis. Analyses showed that B. burgdorferi s.l. has been consistently present in British tick populations since at least 1897. Ticks positive for B. burgdorferi s.l. DNA were collected in all months of the year, throughout Britain, and were found on a wide range of mammal and bird species. PCR positivity does not prove vector or reservoir competence, but the use of archived material has demonstrated an extensive range of host-tick relationships involving B. burgdorferi s.l. in Britain for > 100 years.

Cyclospora infections in England and Wales: 1993 to 1998.

The coccidian protozoon Cyclospora cayetanensis is a treatable cause of prolonged, watery diarrhoea in humans. Microbiology laboratories in England and Wales often restrict testing to those who have recently travelled abroad. Only 44 to 66 laboratory reports of C. cayetanensis are made in England and Wales each year and a large proportion are found to have visited developing countries. Large foodborne outbreaks of infection have arisen in North America among people who have not travelled abroad but no such outbreaks have been identified in the United Kingdom. Public health laboratories in England and Wales were surveyed in 1998 to investigate their procedures for identifying C. cayetanensis. Sixty-eight per cent actively looked for the protozoon, but only half used a recommended method of direct microscopy of formol ether concentrates. National external quality assurance results for all participating UK laboratories were reviewed to assess laboratory proficiency in identification. C. cayetanensis was correctly identified in a wet preparation by 58% of laboratories, the lowest rate for specimens containing a single parasite species. Cyclosporiasis could be acquired in the UK from imported food, but current laboratory procedures might fail to identify it. Ascertainment must improve and awareness needs to be raised among food handlers, public and environmental health workers, laboratory staff, and general practitioners. We recommend that laboratories test all patients with watery diarrhoea for > 1 week for cyclospora, use formol ether concentration and microscopy with a calibrated eyepiece graticule, and confirm diagnoses with the help of a reference laboratory.

Neisseria meningitidis in a primary school.

A prospective study of the nasopharyngeal carriage of sulphonamide resistant Neisseria meningitidis, group B, type 15 P1.16, was undertaken after a cluster of four cases of meningococcal infections had occurred, two of which were fatal, during a three year period among children attending an inner London primary school. Throughout the year of the study the overall carriage and acquisition rates of meningococci were less than 6% and 1%, respectively, and were no different from those of control children of similar age and ethnic origin from another school. The outbreak strain was isolated from three children in the study school, however, but from none in the control school. A comparison of bactericidal activity in serum against the outbreak strain in children from selected classes in each school showed that there was no lack of bactericidal activity to this strain in the study school. The low prevalence of strain specific bactericidal activity in sera taken from classroom contacts of carriers, combined with the low carriage and acquisition rats, suggested a pattern of prolonged colonisation with infrequent transmission of the organism from child to child, and was consistent with the pattern of cases seen in the school.

Acrodermatitis chronica atrophicans: a case report and review of the literature.

We report a 55-year-old woman with acrodermatitis chronica atrophicans (ACA) and a peripheral sensory neuropathy. ACA is an uncommon late cutaneous manifestation of Lyme disease, which follows disseminated Borrelia burgdorferi infection. This is the second published case from the U.K. since serological diagnosis has been available. In this patient the diagnosis was confirmed by serology using a sensitive enzyme-linked immunosorbent assay and immunoblotting techniques. B. burgdorferi DNA was demonstrated in the affected skin using the polymerase chain reaction, although staining and cultures for the organism were negative. Recommended treatment of ACA is with oral doxycycline 100 mg twice daily for 28 days, but our patient did not respond well to this regimen. She was therefore treated with ceftriaxone intravenously for 21 days, which resulted in a rapid symptomatic and clinical response.

Involvement of multiple Cryptococcus neoformans strains in a single episode of cryptococcosis and reinfection with novel strains in recurrent infection demonstrated by random amplification of polymorphic DNA and DNA fingerprinting.

We compared the abilities of random amplification of polymorphic DNA and DNA fingerprinting, with oligonucleotide probes, to type five pairs of Cryptococcus neoformans clinical isolates recovered from five separate human immunodeficiency virus-positive patients in London, England. The two techniques had comparable discriminatory abilities when applied to these isolates. A total of eight different isolate types were demonstrated in these patients. No isolate type was observed in more than one patient. Two of the isolate pairs recovered from single episodes of cryptococcosis within 1 day of each other were genotypically indistinguishable by both methods. The other three pairs of isolates were all distinguishable. One of these isolate pairs was obtained from a single episode of cryptococcosis, while the other two were obtained from recurrent infections. These results indicate that multiple strains of C. neoformans may be responsible for a single episode of cryptococcosis and that recurrent infection may occur as a result of reinfection with a novel strain.