First report of human anisakidosis in Australia.

We present the first human case of anisakidosis acquired from eating locally caught fish in Australia. A 41-year-old woman experienced gastrointestinal pain, vomiting and diarrhoea of increasing severity over 3 weeks. All symptoms resolved spontaneously after a worm was passed in her faeces. Microscopic examination showed that it was a Contracaecum species larva of the family Anisakidae. Anisakidosis should be considered in patients with gastrointestinal symptoms who have recently eaten seafood.

Cutaneous larva migrans in infants in the Adelaide Hills.

Four infants aged between 8 and 13 months presented between November 2002 and May 2006 with dermatitis of the lower abdomen, perineum or buttocks. All lived in semi-rural properties in the Adelaide Hills and had not travelled outside South Australia. Wandering thread-like serpiginous tracks were evident on examination, consistent with a diagnosis of cutaneous larva migrans. No abnormalities were detected on full blood examination, Strongyloides stercoralis serology or faecal analysis. Treatment with oral albendazole resulted in rapid resolution of symptoms. An epidemiological survey was undertaken which suggested possums or millipedes may have been the source of nematode larvae, the precise nature of which is unclear but could include Parastrongyloides trichosuri and Rhabditis necromena.

In vitro activity of mupirocin on clinical isolates of Staphylococcus aureus and its potential implications in chronic rhinosinusitis.

BACKGROUND: It has been postulated that bacterial biofilms are involved in the pathogenesis of chronic rhinosinusitis (CRS). Biofilms present on sinus mucosa are difficult to eradicate with conventional antibiotic therapy and are thought to provide a nidus for recurrent infection. Topical delivery of antibiotics via nasal irrigation may present a way of delivering high concentrations of antibiofilm agents with potentially low systemic absorption and side effects. This study investigates the effectiveness of mupirocin and two other antibiotics, ciprofloxacin and vancomycin, on established in vitro biofilms of Staphylococcus aureus isolated from patients with CRS. METHODS: S. aureus American Type Culture Collection 25923 and 12 clinical isolates were investigated for their ability to form biofilms in an in vitro setting using a 96 well microtiter crystal violet (CV) plate assay and confocal scanning laser microscopy (CSLM). Antimicrobial susceptibility tests to determine minimum inhibitory concentrations were performed on planktonic and biofilm forming strains. In addition, established biofilms were subjected to the antimicrobial agents at a twofold dilution series. A CV analysis of biofilm mass was performed after 1 and 24 hours of treatment, and minimum biofilm inhibition concentrations at 50% (MIB50) and 90% (MIB90) biofilm inhibition were recorded. RESULTS: With use of a 96-well microtiter plate CV assay, 8 of the 12 clinical isolates formed mature biofilms after 8 days of culture. These results correlated with findings from CSLM analysis of in vitro biofilms grown on Permanox chamber slides. Increased antimicrobial resistance was observed in the biofilm isolates when compared with planktonic counterparts. Mupirocin was capable of reducing biofilm mass by greater than 90% at concentrations of 125 mug/mL or less in all S. aureus isolates. Ciprofloxacin and vancomycin were largely ineffective in attaining MIB90 concentrations within safe dosage ranges. CONCLUSIONS: The topical application of mupirocin via nasal irrigation may be useful in eliminating S. aureus biofilms present on the sinus mucosa of patients with CRS and may offer an additional treatment to patients with recalcitrant sinusitis.

First report of septicemia caused by an obligately anaerobic Staphylococcus aureus infection in a human.

In this case report, we describe the first instance of septicemia caused by an obligately anaerobic Staphylococcus aureus in a human. A 45-year-old man presented with septicemia, septic arthritis, and multiple pulmonary abscesses, which were caused by an obligately anaerobic S. aureus. The clinical and microbiological features that led to the diagnosis are discussed. Genotyping cannot at present reliably separate S. aureus subsp. aureus from S. aureus subsp. anaerobius, but phenotypic characteristics suggest that the present isolate is a previously undescribed strain of anaerobic Staphylococcus aureus.

Response to re-infection with Brachylaima cribbi in immunocompetent and immunodeficient mice.

The course of infection in C57BL/6J mice re-infected with Brachylaima cribbi was assessed by comparing faecal egg excretion of re-infected mice with age- and sex-matched mice receiving a primary infection only. For both male and female mice there was a significant reduction in the mean number of eggs per gram of faeces at the peak of infection 4 weeks after the challenge infection compared with mice receiving a primary infection only. There was no significant difference in the duration of the infection. This experiment was repeated using age-matched male mice but on this occasion all mice were killed and dissected 4 weeks after the challenge infection and mean eggs per gram of faeces, worm burden and fecundity determined. There was no significant difference in the worm burdens of the re-infected mice compared with age-matched animals receiving a primary infection only. However, there were significant differences in the mean faecal eggs per gram and worm fecundity with the challenge infection group having lower egg counts and reduced fecundity. An enzyme-linked immunosorbent assay using whole worm antigens was developed and used to determine mouse anti-B. cribbi serum antibody levels during the course of infection. Anti-B. cribbi serum antibody absorbance ratios increased six- to sevenfold by 4 weeks after a primary infection beyond which a constant level was maintained. The course of challenge infection in non-obese diabetic severe combined immunodeficient mice showed no significant differences in egg excretion, worm burden or fecundity when primary and challenge infections were compared. These results indicate that the immune response invoked by a previous B. cribbi infection in immunocompetent mice affects fecundity but does not affect the establishment or duration of infection.

Effects of sex and age on the susceptibility of C57BL/6J mice to infection with Brachylaima cribbi and the course of infection in NOD SCID mice.

The C57BL/6J strain of Mus musculus is susceptible to the terrestrial trematode Brachylaima cribbi. The duration of infection in these mice is generally 9-12 weeks with a peak excretion of eggs at 4 weeks post-infection (wpi). The effects of age and sex on the course of infection were investigated by comparing infections in male and female mice aged 8 or 28 weeks at the time of infection. There were no significant differences in the susceptibility of the adolescent mice of either sex or older male mice. However, older, mature female mice were significantly more resistant to B. cribbi infection than older mature males and adolescent females with reduced worm burden, fecundity and egg fertility. In comparison with young males, all three parameters were again reduced but this was only significant statistically for reduced egg fertility. It is likely that mature female sex hormones influence resistance to B. cribbi infection. The susceptibility of immunodeficient NOD SCID mice was evaluated and compared with C57BL/6J mice. NOD SCID mice were susceptible to B. cribbi infection with the infection persisting with a relatively unchanged worm burden for the life of the mouse with the longest surviving mice being 31 wpi. The life-span of B. cribbi is therefore at least 31 weeks. There were no significant differences in egg excretion, worm burden or fecundity among NOD SCID mice at 4, 8 or 18 wpi. As the infection progressed in NOD SCID mice, the location of worms in the small intestine moved from the anterior third in the early stages of the infection to the mid- to posterior intestine in the later stages. Comparison of the infection in NOD SCID mice with C57BL/6J mice indicates that the expulsion of worms in the latter is mediated by an immune response.

The susceptibility of inbred mice to infection with Brachylaima cribbi (Digenea: Brachylaimidae).

Susceptibility to infection with Brachylaima cribbi was studied in eight strains of inbred mice (AKR, C3H/HeJ, CBA/CaH, BALB/c, DBA/2J, SJL/J, A/J, C57BL/6J) and Swiss albino outbred mice by quantifying faecal egg excretion over the period of the infection. Preliminary experiments indicated that a combination of filtration/sedimentation/diethyl ether sedimentation was the most sensitive and reliable technique for quantification of eggs in faeces. Mice were infected with 13-15 wild-type B. cribbi metacercariae from naturally infected Cernuella virgata and in a second experiment with human-derived B. cribbi from laboratory-reared Helix aspersa. In both experiments C57BL/6J mice were the most susceptible having the highest egg excretion levels and the longest duration of infection. Worm burdens were assessed at 12 wpi for the wild-type and at 9 wpi for the human-derived infections, when the majority of mice were no longer excreting eggs. The numbers of worms recovered from the small intestine were few and there were no significant differences among the inbred or outbred groups of mice. We have found that C57BL/6J mice were the most susceptible to Brachylaima cribbi infection as assessed by excretion of eggs and provide a suitable model for a laboratory life-cycle.