National Center for Biotechnology Information NCBI NLM MEDLINE animals humans pubmed abstract nih national institutes of health national library of medicine research support u.s. gov't non-p.h.s. Comparative Study P.H.S. risk factors drug resistance case-control studies bacterial typing techniques population surveillance anti-infective agents / therapeutic use microbial anti-infective agents / pharmacology* analysis of variance campylobacter infections / epidemiology ciprofloxacin / pharmacology travel campylobacter infections / microbiology* pmid:10332013 doi:10.1056/nejm199905203402001 k e smith j m besser m t osterholm campylobacter jejuni* / classification campylobacter jejuni* / drug effects campylobacter jejuni* / isolation & purification chickens / microbiology meat / microbiology* minnesota / epidemiology nalidixic acid / pharmacology