Resistance to clarithromycin and genotypes in Helicobacter pylori strains isolated in Sicily.
The resistance of Helicobacter pylori strains to clarithromycin is increasing in several developed countries and their association with a genetic pattern circulation has been variously explained as related to different geographical areas. In this study we have reported: the prevalence of the resistance of H. pylori, isolated in Sicily, to clarithromycin; the principal point of mutation associated with this resistance; and the more frequent association between resistance to clarithromycin and cagA, the EPIYA motif, and the vacA and oipA genes. Resistance to clarithromycin was detected in 25% of cases, the main genetic mutation involved being A2143G. The cagA gene was present in 48% of cases and the distribution of the EPIYA motif was: ABC in 35 cases; ABCC in 8 cases; ABCCC in 2 cases; ABC-ABCC in 2 cases; and ABC-ABCC-ABCCC in 1 case. Regarding the vacA allele, an s1i1m1 combination was detected in 35% of cases, s1i1m2 in 12 %, s1i2m2 in 12%, s2i2m2 in 40%, and a double s1m1-m2 mosaic in 1% of cases. The status of the oipA gene was 'off' in 45% of cases and 'on' in 55%. Resistance to clarithromycin was found to be high in Sicily, but no correlation was found among resistance to clarithromycin, the vacA gene and oipA status; a higher correlation was observed between resistant strains and cagA-negative strains.
Department of Sciences for Health Promotion and Mother and Child care 'G. D'Alessandro', University of Palermo, Via del Vespro 133, 90127 Palermo, Italy.
Teresa
T
Fasciana
Department of Sciences for Health Promotion and Mother and Child care 'G. D'Alessandro', University of Palermo, Via del Vespro 133, 90127 Palermo, Italy.
Cinzia
C
Calà
Department of Sciences for Health Promotion and Mother and Child care 'G. D'Alessandro', University of Palermo, Via del Vespro 133, 90127 Palermo, Italy.
Celestino
C
Bonura
Department of Sciences for Health Promotion and Mother and Child care 'G. D'Alessandro', University of Palermo, Via del Vespro 133, 90127 Palermo, Italy.
Enza
E
Di Carlo
Department of Sciences for Health Promotion and Mother and Child care 'G. D'Alessandro', University of Palermo, Via del Vespro 133, 90127 Palermo, Italy.
Domenica
D
Matranga
Gastroenterology Division, M. Raimondi Hospital, Via Forlanini no. 5, 93017 San Cataldo (CL), Italy.
Giuseppe
G
Scarpulla
Gastroenterology Division, M. Raimondi Hospital, Via Forlanini no. 5, 93017 San Cataldo (CL), Italy.
Michele
M
Manganaro
Gastroenterology Division, M. Raimondi Hospital, Via Forlanini no. 5, 93017 San Cataldo (CL), Italy.
Salvatore
S
Camilleri
Department of Sciences for Health Promotion and Mother and Child care 'G. D'Alessandro', University of Palermo, Via del Vespro 133, 90127 Palermo, Italy.
Anna
A
Giammanco
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D017291:Clarithromycin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008969:Molecular Sequence Data; D015995:Prevalence; D012802:Sicily; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D037521:Virulence Factors; D017291:Clarithromycin