Rare Cryptosporidium hominis Subtype Associated with Aquatic Center Use

To investigate the mechanism of resistance in the isolates, fragments of gyrA (847 bp) and parC (822 bp) genes were amplifi ed by using primers gyrA1F (5′-gttttcccagtcacgacgttgtaATGA CCGACGCAACCATCCGCCAC-3′) and gyrA-1R (5′-ttgtgagcggataacaattt cCCAGCTTGGCTTTGTTGACCTG ATAG-3′), and parC-1F (5′-gttttcccag tcacgacgttgtaATGAATACGCAAGC GCACGCCCCA-3′) and parC-1R (5′ttgtgagcggataacaatttcGGAATTGGC GTTCGGCGGCAGCTC-3′), respectively (sequences in lower case letters are adaptors for universal forward and reverse sequences were added for sequencing after amplifi cation). Primers used for amplifi cation of the parE gene were as described (8). Sequencing of fragments of gyrA, parC, and parE genes showed a mutation in the gyrA gene in the 3 Cip-R isolates resulting in a Thr91 → Ile substitution. Cip-R1 also showed additional alterations of Asn103 → Asp, Ile111 → Val, and Val120 → Ile, which were described for meningococcal isolates (3). Sequences of parC and parE genes were the same as in a ciprofl oxacin-susceptible isolate tested. The association of the Cip-R phenotype with mutations in gyrA was confi rmed by transformation into the susceptible isolate by using appropriate PCR products (9). In addition to the common Thr91 → Ile substitution, the 3 Cip-R isolates were distinguishable by additional gyrA alterations or phenotypic and genotypic characteristics. This fi nding suggests independent events and argues against clonal expansion of Cip-R meningococci. Serogroup A meningococcal isolates in France are rare and mostly imported. Lack of detection of ciprofl oxacin resistance among African isolates tested in this study may be caused by the relatively low number of these isolates (n = 246). Therefore, surveillance of antimicrobial drug susceptibility of meningococcal isolates should be enhanced by using molecular approaches that can also be used as nonculture techniques. This molecular approach will be useful in countries with limited access to classic microbiologic culture–based methods. Reports of invasive cases caused by W-135 Cip-R meningococci should alert physicians who use quinolones to treat respiratory infections in elderly persons. This age group is affected most often by invasive meningococcal pneumonia and 54.5% of such cases are caused by W-135 meningococci (10).