Predominance of dfrG as determinant of trimethoprim resistance in imported Staphylococcus aureus.

To investigate the global occurrence of trimethoprim-sulfamethoxazole resistance and the genetic mechanisms of trimethoprim resistance, we analysed Staphylococcus aureus from travel-associated skin and soft-tissue infections treated at 13 travel clinics in Europe. Thirty-eight per cent (75/196) were trimethoprim-resistant and 21% (41/196) were resistant to trimethoprim-sulfamethoxazole. Among methicillin-resistant S. aureus, these proportions were 30% (7/23) and 17% (4/23), respectively. DfrG explained 92% (69/75) of all trimethoprim resistance in S. aureus. Travel to South Asia was associated with the highest risk of acquiring trimethoprim-sulfamethoxazole-resistant S. aureus. We conclude that globally dfrG is the predominant determinant of trimethoprim resistance in human S. aureus infection.

Skin and soft tissue infections in intercontinental travellers and the import of multi-resistant Staphylococcus aureus to Europe.

Staphylococcus aureus is emerging globally. Treatment of infections is complicated by increasing antibiotic resistance. We collected clinical data and swabs of returnees with skin and soft tissue infections (SSTI) at 13 travel-clinics in Europe (www.staphtrav.eu). Sixty-two percent (196/318) SSTI patients had S. aureus-positive lesions, of which almost two-thirds (122/196) were Panton-Valentine leukocidin (PVL) positive. PVL was associated with disease severity, including hospitalization for SSTI (OR 5.2, 95% CI 1.5-18.2). In returnees with SSTI, longer travel and more intense population contact were risk factors for nasal colonization with PVL-positive S. aureus. Imported S. aureus frequently proved resistant to trimethoprim-sulfamethoxazole (21%), erythromycin (21%), tetracycline (20%), ciprofloxacin (13%), methicillin (12%) and clindamycin (8%). Place of exposure was significantly (p < 0.05) associated with predominant resistance phenotypes and spa genotypes: Latin America (methicillin; t008/CC24/304), Africa (tetracycline, trimethoprim-sulfamethoxazole; t084/CC84, t314/singleton, t355/CC355), South Asia (trimethoprim-sulfamethoxazole, ciprofloxacin; t021/CC21/318), South-East Asia (clindamycin; t159/CC272). USA300-like isolates accounted for 30% of all methicillin-resistant S. aureus imported to Europe and were predominantly (71%) acquired in Latin America. Multi-resistance to non-ß-lactams were present in 24% of imports and associated with travel to South Asia (ORcrude 5.3, 95% CI 2.4-11.8), even after adjusting for confounding by genotype (ORadjusted 3.8, 95% 1.5-9.5). Choosing randomly from compounds recommended for the empiric treatment of severe S. aureus SSTI, 15% of cases would have received ineffective antimicrobial therapy. These findings call for the development of regionally stratified guidance on the antibiotic management of severe imported S. aureus disease and put the infected and colonized traveller at the centre of interventions against the global spread of multi-resistant S. aureus.

Prevalence and clinical importance of Entamoeba histolytica in two high-risk groups: travelers returning from the tropics and male homosexuals.

This study was undertaken to learn the prevalence of amebiasis and to assess the clinical importance of Entamoeba histolytica in two high-risk groups: 2700 travelers returning from the tropics and 320 male homosexuals. Some 16.3% of the homosexual men and 4.0% of the travelers had E. histolytica infections. Only five travelers showed a pathogenic zymodeme of E. histolytica, which correlated closely with invasive amebiasis with positive amebic serology and clinical symptoms with diarrhea. The homosexual group had neither a pathogenic isoenzyme pattern nor positive amebic serology. Currently, travelers to the tropics have a risk of 0.3% (1:340) of acquiring invasive amebiasis; 92.5% of all E. histolytica infections in travelers remain asymptomatic and are confirmed by serology and zymodeme status. No homosexual presented with invasive amebiasis.

[The importance of Entamoeba histolytica in persons returning from the tropics]. / Bedeutung von Entamoeba histolytica bei Tropenrückkehrern.

Stools from 1000 travellers returning from the tropics were examined for intestinal parasites. The most frequently isolated intestinal pathogens were Giardia lamblia (5%) and E. histolytica (3.6%). For 21 out of 36 E. histolytica isolates iso-enzyme differentiation by starch-gel electrophoresis was possible, yielding a pathogenic pattern in four. This finding correlated closely with clinical symptoms and positive serology, while E. histolytica with non-pathogenic zymodeme should not be considered as a cause of diarrhoea.

Amebic liver abscess in a European patient: zymodeme classification of Entamoeba histolytica.

This is a case report of a 36-year-old patient who developed an amebic liver abscess after a stay in the Sudan. He was first misdiagnosed as having pneumonia of the right lower lobe. Following establishment of the correct diagnosis, the patient recovered fully after metronidazole treatment. The fecal culture in Robinson's medium yielded extensive growth of Entamoeba histolytica. Electrophoretic characterization proved it to be a zymodeme XIX, which is one of the zymodemes associated with pathogenicity in the host. This first report of a zymodeme classification of E. histolytica in Germany should initiate further epidemiological studies.

Isoenzyme patterns of Entamoeba histolytica isolated from homosexual men.

This is a preliminary report on isoenzyme patterns of Entamoeba histolytica which were examined by starch gel electrophoresis. By this means the amoebae isolated from 17 asymptomatic male homosexuals were characterized into zymodemes. No amoebic strain isolated corresponded to a pathogenic zymodeme.