Ten patients with bacteremia due to methicillin-resistant Staphylococcus aureus were treated with vancomycin. These patients were compared with matched controls, nine bacteremic patients with methicillin-sensitive S. aureus, and one patient with penicillin-sensitive S. aureus. Controls were treated with a penicillin. There were no significant differences in time to defervescence, metastatic infections, relapse, mortality, need for surgical drainage, or duration of therapy. Fifteen of 19 episodes of serious methicillin-resistant S. aureus infection responded to vancomycin. Severe toxic effects included tinnitus, neutropenia, rash, and possible nephrotoxicity. Tolerance (a minimal bactericidal concentration to minimal inhibitory concentration ratio of at least 32), but not a minimal bactericidal concentration of at least 32 mg/L, correlated with therapeutic failure (respectively, p = 0.04 and p = 0.11, Fisher's exact test). Bacteremic infections due to methicillin-resistant and methicillin-sensitive S. aureus cause similar morbidity and mortality. Vancomycin is effective but potentially toxic therapy for most serious infections due to methicillin-resistant S. aureus. In-vitro tests may not predict therapeutic efficacy.

SUMMARYHorizontal transmission of Campylobacter jejuni was investigated in campylobacter-free broiler chicks. One hundred and twenty chicks housed individually, were provided with water containing 1O2-1O9 c.f.u./ml C. jejuni. Colonization was rapid [47 of 73 (64 %) positive cloacal cultures within 3 days and 65 of 73 (89 %) within 7 days], dependent on C. jejuni strain and inoculum size but independent of chick age. Groups of 5-24 chicks in isolators were exposed to C. jejuni-contaminated water or colonized seeder chicks. Transmission occurred in 2-7 days concurrent with a gradual increase of C. jejuni in litter, water and feed. Environmental samples were culture-negative within 3 days following removal of colonized chicks. Treatment of 1-day-old chicks with adult caecal microbiota did not affect colonization. Treated and control chicks were all C. jejuni-positive within 3 days of seeder challenge.

SUMMARYThe role of broiler eggs in the transmission ofCampylobacter jejunito broiler grow-out flocks was investigated. Six breeder flocks supplying broiler eggs to hatcheries were examined for cloacal carriage ofC. jejuni. Of 240 birds tested, 178 (74%) wereC. jejuni-positive. Eggs from these birds examined forC. jejunipenetration of the egg shell indicated that 185 of 187 were campylobacter-free. Eggs from breeder flocks of unknownC. jejunistatus were also examined forC. jejunishell penetration.C. jejuniwas not isolated from 142 eggs examined. A further 193 hatchery eggs incubated and hatched in the laboratory were campylobacter-free. Six farms containing the progeny ofC. jejuni-positive breeder flocks were monitored. Eight hundred and forty birds from 14 flocks m these grow-out farms were campylobacter-free during their 6-week grow-out period. Experimental egg-penetration studies indicated thatC. jejunitransmission via the egg is not easily effected. Of 257 eggs surface-challenged withC. jejuni, 162 hatched; all were campylobacter-free. Of 167 eggs injected withC. jejuni, 12 hatched; 2 of these were colonized withC. jejuni. Our data do not support a role for vertical transmission ofC. jejuniin commercial broiler production.

Minimal inhibitory and minimal bactericidal concentrations were determined for eighteen methicillin-resistant Staphylococcus aureus isolates, the majority also resistant to gentamicin, obtained from the blood of bacteraemic patients. Fifty per cent of organisms had a greater than four-fold difference in M.I.C. and M.B.C. for vancomycin, 83% for rifampicin, and 89% for fusidic acid. In-vitro effects of two-drug combinations of vancomycin, rifampicin, and fusidic acid demonstrated neither synergy nor antagonism when measured by a checkerboard dilution technique. The relevance of these findings to choice of therapy of serious infection due to methicillin-gentamicin resistant Staph. aureus is yet to be determined.

Minimal colonization inocula for two broiler strains of Campylobacter jejuni were determined in broiler chicks aged 2-3 days and 2 weeks. Individually housed chicks were exposed to a single oral or cloacal challenge. Diarrhoeal symptoms were absent in all 380 chicks included in the study. Chick susceptibility to the two C. jejuni strains varied. Colonization was effected by less than 10(2)-10(4) colony forming units (c.f.u.) via cloacal challenge and 10(4)-10(6) c.f.u. via the oral route. Colonization inocula for 2- to 3-day and 2-week-old chicks were similar. Treatment of 1-day-old chicks with fresh adult caecal flora or an anaerobic broth culture of adult caecal flora did not inhibit colonization after challenge with low-dose C. jejuni. Susceptible chicks were colonized rapidly. C. jejuni was detected in 167 of 189 (88%) colonized chicks within 3 days of challenge and persisted during the 2-week monitoring period. Our data suggest that colonization of broiler chicks with C. jejuni is effected more easily by the cloacal than the oral route and is independent of age.