Antibiotic treatment is not required in cases of Salmonella enterica gastroenteritis but is essential in cases of enteric fever or invasive salmonellosis or in immunocompromised patients. Although fluoroquinolones and extended-spectrum cephalosporins are the drugs of choice to treat invasive Salmonella , resistance to these antibiotics is increasing worldwide. During the period 2000 to 2003, 90 Salmonella enterica serovar Virchow poultry and poultry product isolates and 11 serovar Virchow human isolates were found to produce an extended-spectrum β-lactamase, CTX-M-2, concomitantly with a TEM-1 β-lactamase. The bla CTX-M-2 gene was located on a large conjugative plasmid (>100 kb). Pulsed-field gel electrophoresis indicated a clonal relationship between the poultry and human isolates. All these isolates displayed additional resistance to trimethoprim-sulfamethoxazole and tetracycline as well as a reduced susceptibility to ciprofloxacin (MICs of between 0.5 and 1 μg/ml). CTX-M-2-producing Salmonella with a reduced susceptibility to fluoroquinolones constitutes a major concern, since such strains could disseminate on a large scale and jeopardize classical antibiotic therapy in immunocompromised patients.

To evaluate the usefulness of phenotypic and genotypic analyses for the epidemiologic typing of methicillinresistant Staphylococcus aureus (MRSA), we characterized 64 epidemic MRSA isolates and 10 sporadic methicillin-susceptible S. aureus isolates from a university hospital and 18 MRSA isolates from hospitals in different geographical areas. Chromosomal DNA macrorestriction analysis with Sstll was resolved by pulsed-field gel electrophoresis and compared with antibiotype analysis, phage type analysis, and standard genomic DNA restriction analysis with BgM. Indices of the discriminatory ability of these methods were 0.982,

Mupirocin was used in haemodialysis patients in an attempt to eradicate nasal carriage of Staphylococcus aureus and to prevent infection caused by this microorganism. The effectiveness of calcium mupirocin as a 2% nasal ointment OB2 (16 patients for 104 patient-months) was compared to that of placebo (18 patients for 147 patient-months) in a double-blind study. Mupirocin or placebo were applied in both anterior nares thrice daily for 2 weeks and subsequently three times weekly for a total of 9 months. During therapy, S. aureus was recovered from only 6% of the nasal cultures in the mupirocin group compared to 58% in the placebo group (P less than or equal to 0.01). Only one S. aureus infection was documented in the mupirocin group compared to six in the placebo group (P less than or equal to 0.05). The S. aureus strain causing the single infection in the mupirocin group was of a different phage type to that of the original nasal strain. In contrast, at least four of the six strains causing infection in the placebo group were of similar phage type to the original nasal strain. All S. aureus isolates remained mupirocin sensitive (MIC less than or equal to 1 mg/l). In conclusion, mupirocin nasal ointment was effective in eradicating nasal carriage of S. aureus and in preventing S. aureus infections in patients on haemodialysis.

In Belgium, non-typhoidal salmonellosis and campylobacteriosis are the two most frequently reported foodborne illnesses. During 2005, a 71% decrease of Salmonella Enteritidis infections compared with the average annual number cases in the period 2000-2004 was recorded by the Belgian National Reference Centre for Salmonella and Shigella. After the peak of 1999, the total number of salmonellosis cases decreased gradually, with the exception of 2003 when an increase was again recorded due to the rise of isolates belonging to the serotype Enteritidis. PT4, the predominant phage type of serotype Enteriditis over recent years (except in 2003), became the second most prevalent phage type in 2005 after PT21. We present in this paper the epidemiology (incidence and trends) of human salmonellosis in Belgium and assess the role of the vaccination programme in layer flocks on the decline of the incidence of human salmonellosis and foodborne outbreaks due to S. Enteritidis.