Household transmission of non-toxigenic diphtheria toxin gene-bearing Corynebacterium diphtheriae following a cluster of cutaneous cases in a specialist outpatient setting.

Introduction. Combination of PCR and Elek testing to identify toxigenic corynebacteria has revealed organisms described as non-toxigenic toxin-gene bearing (NTTB) Corynebacterium diphtheriae or C. ulcerans (i.e. PCR tox positive; Elek negative). These organisms carry part or all of tox, but are unable to express diphtheria toxin (DT) and present a challenge to clinical and public health case management.Gap analysis/Hypothesis. There are few data on the theoretical risk of NTTB reversion to toxigenicity. This unique cluster and subsequent epidemiologically linked isolates allowed the opportunity to determine any change in DT expression status.Aim. To characterize a cluster of infections due to NTTB in a skin clinic and subsequent cases in two household contacts.Methodology. Epidemiological and microbiological investigations were carried out according to existing national guidance at the time. Susceptibility testing used gradient strips. The tox operon analysis and multi-locus sequence typing (MLST) was derived from whole-genome sequencing. Alignment of the tox operon and phylogenetic analyses were performed using clustalW, mega, the public core-genome MLST (cgMLST) scheme and an in-house bioinformatic single nucleotide polymorphism (SNP) typing pipeline.Results. Isolates of NTTB C. diphtheriae were recovered from four cases (cases 1 to 4) with epidermolysis bullosa attending the clinic. Two further isolates were subsequently recovered from case 4, >18 months later, and from two household contacts (cases 5 and 6) after a further 18 months and 3.5 years, respectively. All eight strains were NTTB C. diphtheriae biovar mitis, belonged to the same sequence type (ST-336) with the same deletion in tox. Phylogenetic analysis showed relatively high diversity between the eight strains with 7-199 SNP and 3-109 cgMLST loci differences between them. The number of SNPs between the three isolates from case 4 and two household contacts (cases 5 and 6) was 44-70 with 28-38 cgMLST loci differences.Conclusions. We report a cluster of NTTB C. diphtheriae cases in a skin clinic and evidence of onward household transmission. We conclude the deletion in the tox was responsible for the non-expression of DT. There was no evidence of reversion to DT expression over the 6.5 year period studied. These data informed revision to guidance in the management of NTTB cases and their contacts in the UK.

A rare case of Salmonella Paratyphi C osteomyelitis: A genetic analysis and review of Salmonella osteomyelitis in England.

Salmonella osteomyelitis is rare in patients without sickling hemoglobinopathies. Invasive disease caused by Salmonella Paratyphi C is rarer still with only one case reported in the United Kingdom in the last 15 years. We report a case of relapsing S. Paratyphi C osteomyelitis in a newly diagnosed diabetic patient from Ghana. Our patient was initially treated successfully with surgical debridement followed by 6 weeks of IV ceftriaxone before recrudescence 9 months later. Due to the rarity of S. Paratyphi C and the lack of recent travel, genomic analysis was undertaken to assess possible sources with the closest related strain being from Cote d'Ivoire. The patient had likley picked up the strain several years before presentation. We review current Salmonella osteomyelitis literature and audit all cases referred to the England and Wales Salmonella national reference laboratory over the last 15 years.

Ophthalmomyiasis externa caused by Oestrus ovis.

This report describes the case of a woman in her early 20s who presented with a 3-day history of mobile foreign bodies and watering from her right eye. She had recently returned from vacation on a Greek island and presented to an ophthalmology unit in London, UK. A sample taken demonstrated Oestrus ovis infestation and confirmed the diagnosis of ophthalmomyiasis externa. She was treated with prophylactic topical antibiotics and subsequently made a full recovery. This was only the sixth presentation of O. ovis ophthalmomyiasis externa documented within the UK and the only case documented within the last 20 years. This is the fifth documented case found to have been transmitted within Greece.

Pattern of culture-proven neonatal sepsis in a district general hospital in the United Kingdom.

OBJECTIVE: To determine the incidence, clinical characteristics, and risk factors associated with the first culture-proven episode of sepsis among neonates in a neonatal intensive care unit (NICU). SETTING: Level-II NICU in the United Kingdom. PATIENTS: Neonates with their first culture-proven sepsis between January 1, 1996, and December 31, 2000. METHODS: Demographic data were obtained from the NICU database and chart review. Sepsis was considered early (EOS; < 72 hours old) or late (LOS; > 72 hours old). Data were also collected on potential risk factors. RESULTS: Among 14,767 live births, 1,612 (11%) neonates were admitted to the NICU during the study period. Nine hundred eight were screened for sepsis. One hundred twenty-four had at least one positive culture (overall sepsis rate of 8.4 per 1,000 live births [1%] or 77 per 1,000 NICU admissions). Twenty-four neonates had EOS and 100 had LOS. Coagulase-negative staphylococci (CoNS) and group B Streptococcus were the most frequent organisms causing EOS, whereas CoNS and Escherichia coli most frequently caused LOS. Birth before 30 weeks' gestation and birth weight less than 1,500 g were risk factors for sepsis. Resuscitation at birth was the leading risk factor for EOS and respiratory support prior to sepsis, presence of a central or peripheral catheter, and total parenteral nutrition were leading risk factors for LOS. CONCLUSIONS: A strong inverse relationship existed between gestational age of 30 weeks or younger and birth weight of 1,500 g or less and LOS. Resuscitation and indwelling intravenous catheters were also risk factors.