DISSEMINATION AMONG STAPHYLOCOCCI OF DNA-SEQUENCES ASSOCIATED WITH METHICILLIN RESISTANCE
DISSEMINATION AMONG STAPHYLOCOCCI OF DNA-SEQUENCES ASSOCIATED WITH METHICILLIN RESISTANCE
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DOI：
10.1128/aac.38.3.447
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发表时间：
1994-03-01
影响因子：
4.9
通讯作者：
PUCCI, MJ
中科院分区：
文献类型：
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作者：
ARCHER, GL;NIEMEYER, DM;PUCCI, MJ
以介导甲氧西林耐药基因5′~ mecA不同DNA序列的2株耐甲氧西林金黄色葡萄球菌为材料，构建了含克隆金黄色葡萄球菌染色体片段pUC19的DNA探针。其中一个菌株BMS1的探针包含部分调控序列（mecRI末端641 bp）和所有与诱导和抑制mecA转录相关的mecI （pG0195）。第二个探针来自菌株COL (pG0198)，含有菌株BMS1中未发现的DNA。该DNA位于mecRI缺失位点添加的序列内。1961年至1969年间发现的14株金黄色葡萄球菌的基因组消化结果均与pG0198杂交。相比之下，1988年以来分离的46株金黄色葡萄球菌中有36株（78%）与pG0195杂交，但未与pG0198杂交；其余的与pG0198杂交。两种探针均未分离到金黄色葡萄球菌。表皮葡萄球菌消化物与pG0198（46%）、pG0195（14%）或两种探针杂交（35%）；20株溶血葡萄球菌均与pG0198杂交。金黄色葡萄球菌所有pgo198杂交区限制性内切片段长度多态性模式与col株相同，8株金黄色葡萄球菌和6株表皮葡萄球菌的mecRI缺失连接核苷酸序列相同。23株表皮葡萄球菌和20株溶血葡萄球菌中有21株与pGO198杂交的额外染色体带在5 ~ 20个之间；21株金黄色葡萄球菌均无附加杂交带。这些数据表明，负责mecRI缺失的额外DNA是凝固酶阴性葡萄球菌中存在的重复且可能移动的元素的一部分，而不是金黄色葡萄球菌。这些数据也支持了一种假设，即缺失事件发生在凝固酶阴性葡萄球菌中，随后被金黄色葡萄球菌获得中断的序列。
DNA probes consisting of pUC19 containing cloned Staphylococcus aureus chromosomal fragments were constructed from two methicillin-resistant S. aureus strains with different DNA sequences 5' to mecA, the gene that mediates methicillin resistance. The probe from one strain, BMS1, contained a portion of the regulatory sequences (the terminal 641 bp of mecRI and all of mecI associated with the induction and repression of mecA transcription (pG0195). The Second probe, from strain COL (pG0198), contained DNA not found in strain BMS1. This DNA was within the sequences added at the site of a mecRI deletion. Genomic digests of 14 S. aureus isolates recovered between 1961 and 1969 all hybridized with pG0198. In contrast, 78% (36 of 46) of the S. aureus organisms isolated since 1988 hybridized with pG0195 but not with pG0198; the remainder hybridized,vith pG0198. No S. aureus isolates hybridized with both probes. Staphylococcus epidermidis digests hybridized with pG0198 (46%), pG0195 (14%), or both probes (35%); all 20 Staphylococcus haemolyticus isolates hybridized with pG0198. The restriction fragment length polymorphism patterns of all pGO198-hybridizing regions in S. aureus were identical to those in strain COL. In addition, the mecRI deletion junction nucleotide sequences of eight S. aureus and six S. epidermidis isolates were identical. However, 21 of 23 S. epidermidis and all 20 S. haemolyticus isolates had from 5 to more than 20 additional chromosomal bands that hybridized with pGO198; none of 21 S. aureus isolates had additional hybridizing bands. These data suggest that the additional DNA responsible for the mecRI deletion was part of a repetitive, and possibly mobile, element resident in coagulase-negative staphylococci but not in S. aureus. These data also support a hypothesis that the deletion event occurred in a coagulase-negative staphylococcus with subsequent acquisition of the interrupted sequences by S. aureus.