Rossi A, Corso A, Pace J, Regueira M, Tomasz A
Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas, A.N.L.I.S, Dr. C. Malbrán, Buenos Aires, Argentina.
Microb Drug Resist. 1998 Fall;4(3):225-31. doi: 10.1089/mdr.1998.4.225.
Six Latin-American countries participated in an epidemiological surveillance study conducted by the Pan American Health Organization in order to determine the relative prevalence of capsular types and antimicrobial resistance patterns of Streptococcus pneumoniae (SPN) causing invasive infections in children <5 years of age. In Argentina, the incidence of penicillin resistance (PR) was 24.4%, and it was significantly associated with serotype 14 (p < 0.001). The chromosomal DNA of 56 of those SPN isolates, 39 PR and 17 susceptible, was digested with SmaI and resolved by PFGE. Eighty-two percent (32/39) of the PR isolates shared characteristics with the widely spread International Spanish/French clone (clone B). All members of clone B except one expressed serotype 14, with the exception of one isolate that expressed serotype 19F and probably resulted from an in vivo capsular transformation event. Only a single isolate shared features with the 23F International Spanish/USA clone (clone A). The 17 penicillin-susceptible (PS) SPN isolates presented an enormous degree of variation in the chromosomal background, expressing 12 serotypes and 13 PFGE patterns. The data suggest that over 80% of the SPN-PR isolates in Argentina were imported, and this confirms the importance of the geographic spread of SPN clones in South America.
六个拉丁美洲国家参与了泛美卫生组织开展的一项流行病学监测研究，以确定引起5岁以下儿童侵袭性感染的肺炎链球菌（SPN）的荚膜类型相对流行率和抗菌药物耐药模式。在阿根廷，青霉素耐药（PR）发生率为24.4%，且与14型显著相关（p<0.001）。对其中56株SPN分离株的染色体DNA（39株PR分离株和17株敏感分离株）用SmaI进行酶切，并通过脉冲场凝胶电泳（PFGE）进行分析。82%（32/39）的PR分离株与广泛传播的国际西班牙/法国克隆株（克隆B）具有共同特征。除一株外，克隆B的所有成员均表达14型，有一株表达19F型，可能是体内荚膜转化事件导致的。只有一株分离株与23F国际西班牙/美国克隆株（克隆A）具有共同特征。17株青霉素敏感（PS）SPN分离株的染色体背景存在很大差异，表达12种血清型和13种PFGE模式。数据表明，阿根廷超过80%的SPN-PR分离株是输入性的，这证实了SPN克隆在南美洲地理传播的重要性。
