八仙樂園塵暴病人分離之Staphylococcos haemolyticus菌株基因型及表現型特徵

Characteristics of genotype and phenotype of Staphylococcos haemolyticus isolated from the burned patients in Formosa Fun Coast Water Park fire disaster

2015 年八仙樂園的粉塵爆炸事件，造成了 499 名年輕男女 的嚴重燒傷，此次意外本院收治了 59 名病患，有 36 人的檢體經細菌培養皆分離出 S. haemolyticus，本 研究的目的即是分析這些 S. haemolyticus 菌株的基因型及表現型特性，釐清此菌株在導致病人感染中扮演的 角色，及是否來自於相同的來源。研究中收集 26 位本次塵暴病患由血液，組織等檢體分離的S. haemolyti cus 菌株 69 株，及於同一時期本院其他病房非塵暴 病患的血液，體液及組織等檢體分離的菌株 37 株．以 disc diffusion method 進行藥物的藥物敏感性試驗， 並同時以脈衝式電場膠體電泳法(Pulsed-field gel electrophoresis [PFGE])及多位基因序列分析法 (Multilocus sequence typing [MLST]) 方式進行基因型的分析。PFGE 基因型分析結果顯示，106 株的S. haemolyticus 共 可分為 22 個 pulsotypes (A-V), 塵暴菌株集中於 10 型的 pulsotypes，而 37 株非塵暴菌株則分散於 18 型中， 其中主要型別 pulsotype C 的菌株共有 41 株，52.2%塵暴菌 株屬於此型別，但亦有 13.5%的非塵暴菌株屬於此型別，MLST 的分型結果，共可區分為 13 種 ST 型別 ，其中 7 種新的 ST 型別為本實驗所新建立(ST42 至ST48)，ST42 是此次分析菌株的主要型別，有 68 株(64%) S. haemolyticus 屬於此 ST 型別，塵暴菌株中有 49株(71%)屬於此型，非塵暴菌株中亦有 19 株(51%)屬於 此型，尤其 PFGE 型別的 pulsotype C 菌株有 95%皆為 ST42，ST42 是台灣特有新的且顯著的型別，推測此 major clone 非僅存在八仙樂園的環境中，可能廣泛地存在於台灣，是屬於台灣的 major clone，伺機的引起感染。藥物敏感性試驗結果則顯示，所有S. haemolyticus菌株皆至少對於一種抗生素有抗藥情形，除了 glycopept ide 類藥物外，對於其他抗生素亦有七成以上的抗藥性，而多重抗藥的比率為 62.3% (66 株)，分析塵暴與非 塵暴病患菌株的藥敏試驗結果顯示，塵暴菌株有較高的多重抗藥性比率（52 株，74.4%），尤其是對 cli ndamycin, SXT 兩種藥物的抗藥性有明顯的差別，而基因分型結果中主要型別 pulsotype C -ST42 菌株亦有較強 的抗藥性，不但對於 oxacillin 皆為抗藥，多重抗藥的比率亦高達 87.2% (34/39)。本次的結果顯示此 major clone 的抗藥性強，將增加醫師治療的困難度，故應落實臨床的感控措施，避免引起患者感染．

The fire disaster occurred in Formosa Fun Coast Wa ter Park in June in 2015, Chang Gung Hospital hospitalized a number of 50 patients, and 36 were cultiva ted S. haemolyticus from their specimens. The aim of this study was to analyze the role of S. haemolyticus in th e burned patients and the phenotypic and genotypic characterizations of the bacteria. Drug sensitivity test, PFGE and MLST were conducted on a total of 69 isolates from the burn patients (study group) and 37 were obtained from the non-burn patients (control group) during the same period of time. PFGE data indicated tha t 22 pulsotypes were found in 106 isolates. Only 10 pulsotypes were identified from the study group while 1 8 were from the control group.41 out of 106 isolates belonged to pulsotpye C which was the major type. The study revealed that 52.2% of study group’s isolates belonged to pulsotpye C, but there were also 13.5% of control group’s isolates the major type. The MLST data showed that 13 kinds of ST type found from all isolates. A total of 7 new ST types were established in this study (from ST42 to ST48). ST42 was the major ST type. 68 out of 106 isolates were identified as the major type. Among 68 isolates, 49 (71%) were from the study group a nd 19 (51%) from the control group. Above all, 95% of pulsotype C isolates were ST42. ST42 is a new ST type t hat predominates in the area of Taiwan. We presume that the major clone does not only exist in Formosa Fun Coast Water Park but also is widespread in Taiwan area. Our analysis revealed that all isolates were resistant at least to one antibiotic and had a multi- resistance rate up to 62.3%. The isolates from the study group wer e all oxacillin-resistant and had higher resistant rate toward clindamycin and SXT than the control group （ 82.6%, 84.1% vs 54.1%, 54.1%）.Our study data indicates the major clone has high resistant rate to antibio tics (up to 83% isolates were multi-resistant) which will increase the difficulties in treatments. Therefore, to reinforce infection controls is helpful to decrease the opportunity of infection.