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ObjectivesTo determine the proportion of skin/soft tissue infections (SSTIs) and to determine risks for MRSA infection caused by methicillin-resistant Staphylococcus aureus (MRSA) in HIV-infected out-patients. MethodsWe conducted a prospective study of SSTIs in HIV-infected out-patients. A questionnaire was used to record MRSA risk factors and treatment. In vitro testing for antibiotic susceptibility, inducible clindamycin resistance, panton-valentine leucocidin (PVL) toxin, and the staphylococcal chromosomal cassette mec (SCCmec) type was performed using standardized methods. Treatment outcomes included resolution of primary site of infection, nonresolution of infection and reinfection and were confirmed at clinic visit and/or telephone follow-up. ResultsForty-one of 44 patients had an SSTI caused by MRSA. African-Americans comprised 21 of 41 MRSA patients. The median CD4 count of MRSA patients was 411 cells/mL. Four patients required hospitalization and three patients had secondary bacteraemia. Twenty-one of 41 MRSA patients had healthcare-associated (HCA) MRSA risk factors including a history of prior MRSA infection (n 5 9) and hospitalization within 6 months (n 5 11). Other prevalent MRSA risk factors included receipt of systemic antibiotics within 6 months (n 5 21) and previous incarceration (n 5 19). Twenty-two patients had a significant non-HIV-related comorbid illness. The majority of isolates were susceptible to trimethoprim-sulfamethoxazole, tetracycline, and clindamycin. Inducible clindamycin resistance was detected in 0 of 16 erythromycin-resistant, clindamycin-susceptible MRSA isolates. Twenty-one of 24 isolates tested positive for SCCmec type IV. Twenty-four of 24 isolates tested positive for the PVL gene. Antibiotic treatment was discordant (bacteria nonsusceptible to antibiotic used) in eight MRSA patients. The primary SSTI resolved in 37 of 40 MRSA patients. Recurrence of infection at a site other than the primary site was relatively common (11 patients). ConclusionsWe found a high rate of MRSA causing SSTI in community-dwelling patients. The majority of isolates were positive for PVL and SCCmec IV, which is typical of community-associated MRSA isolates causing SSTIs in the general population. Inducible clindamycin resistance was not detected. Most patients had MRSA risk factors. The initial site of infection resolved in most cases but subsequent MRSA infection was relatively common.

Protein-losing enteropathy occurs in up to 10% of patients following the modified Fontan procedure. Treatment is still controversial. We describe a female adolescent who developed protein-losing enteropathy 4 years after a modified Fontan procedure. Treatment with oral prednisone attenuated the protein loss with subsequent normalization of her serum total protein and albumin levels. Discontinuation of prednisone therapy was associated with relapse, which was again treated successfully with low-dose oral prednisone. Small bowel biopsy-proved diagnosis with improvement, relapse, and improvement again are documented, as are other useful laboratory findings.

The antimicrobial activity of gentamicin, tobramycin, sisomicin, and netilmicin (Sch 20569) was compared against 150 strains of organisms. Netilmicin was shown to be the least effective against Pseudomonas strains but to have slightly better activity against Staphylococcus aureus and Escherichia coli than the other agents. The effect of calcium and magnesium in enhancing the differences in activity of these aminoglycosides against Pseudomonas strains was also demonstrated.This study was carried out to compare the in vitro antibacterial activity of four aminoglycoside antibiotics, gentamicin, tobramycin, sisomicin, and netilmicin (Sch 20569), against 148 clinical isolates and two control strains. There were 50 strains each of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. The control organisms used were P. aeruginosa ATCC 27853 and E. coli ATCC 25922.Minimum inhibitory concentrations (MICs) were determined in the conventional manner in three types of broth: (i) brain heart infusion broth (BHI; BBL 11063) with added calcium and magnesium to provide levels of 75 and 20 mg/liter, respectively; (ii) BHI broth (BBL 11063) unmodified (calcium and magnesium levels were 36 and 14 mg/liter, respectively); and (iii) tryptone broth (Oxord L42). A medium control with no antibiotic added was provided for each organism tested to assure viability, and medium controls with no antibiotic and no organism were also used to assure sterility ofthe medium. Type (i) broth was used for Pseudomonas strains, type (ii) was used for E. coli strains, and type (iii) was used for S. aureus strains.Each tube, other than the medium controls, was inoculated with approximately 104 colonyforming units of the organism under test.The results of the MICs of the four antibiotics against these groups of organisms are shown in Fig. 1 (P. aeruginosa), Fig. 2 (S. aureus), and Fig. 3 (E. coli). These illustrate the relationship between MICs and cumulative percentages of strains inhibited.The most pronounced differences are shown with regard to P. aeruginosa (Fig. 1). At the concentration inhibiting 50% of the strains, the MIC of tobramycin was 0.48 ug/ml and that of netilmicin (Sch 20569) was 3.6 ,Lg/ml, whereas gentamicin and sisomicin were almost inseparable at 1.35 and 1.45 ,ug/ml, respectively. In effect, therefore, a sevenfold difference in activity between tobramycin and netilmicin was demonstrable against this group ofPseudomonas strains isolated using BHI broth with added calcium and magnesium. Figure 2, however, illustrates the converse, in that for the group of staphylococcal isolates tested, the 50% inhibition level was 0.01 ,ug of netilmicin (Sch 20569) and 0.03 ,ug of tobramicin per ml, indicating a threefold difference in activity, but in this instance with netilmicin showing the advantage. Gentamicin and sisomicin occupied intermediate positions in their activity.Netilmicin (Sch 20569) also showed an increase in activity compared with the other aminoglycosides tested against the group ofE. coli strains, although this dif...