待产孕妇鼻腔金黄色葡萄球菌定植状况及其危险因素研究

发布时间：2018-09-05 09:57

【摘要】：目的了解深圳市龙华新区待产孕妇鼻腔金黄色葡萄球菌(Staphylococcus aureus)与耐甲氧西林金黄色葡萄球菌(Methicillin-resistant Staphylococcus aureus,MRSA)的定植状况,探讨影响鼻腔定植的危险因素,并通过分析菌株的耐药谱与分子生物学特征,为预防与控制产妇产后感染与新生儿感染提供科学依据。方法本研究根据横断面研究设计,采用方便抽样的方法选取深圳市龙华新区龙华中心医院与观澜人民医院于2015年8月至2015年11月入院待产的孕妇为调查对象,采用自制调查表对其进行问卷调查与鼻拭子采样。根据一系列实验室标准方法进行菌株的分离鉴定;采用K-B纸片对分离出的金黄色葡萄球菌进行药敏试验;采用PCR技术检测金黄色葡萄球菌特征性基因16S r RNA和nuc,MRSA特征性基因mec A,以及金葡菌携带的毒素基因pvl、tst、eta、etb,并对MRSA菌株进行SCCmec分型。采用多位点测序技术(multilocus sequencing typing,MLST)对金葡菌进行ST分型。数据统计采用Stata 13.0软件进行分析,危险因素分析单因素分析、MSSA与MRSA耐药率比较以及多重耐药菌株与非多重耐药菌株耐药率比较采用χ2检验或Fisher确切概率法,多因素分析采用Logistic回归分析。采用e BURST V3软件与树状图分析软件对本研究分离出的菌株之间,以及与国际流行菌株的亲缘关系进行分析。结果人口学特征:本研究共调查2172名待产孕妇,平均年龄为27.74±4.69周岁,以外地户籍居多,占总体89.72%。家庭妇女占25.99%,工人与农民占16.98%,医务人员占1.48%,文职人员占35.11%,服务行业人员占9.34%,从事个体行业与其他行业者占11.10%。金葡菌与MRSA鼻腔定植率及其危险因素:2172名调查对象中,有556名为金葡菌携带者,鼻腔定植率为25.60%,其中122名为MRSA携带者,总体定植率为5.62%。鼻腔定植金葡菌的单因素分析中,待产孕妇怀孕前BMI与金葡菌鼻腔定植之间的联系有统计学意义(P=0.004)。在多因素分析中,消瘦者金葡菌定植风险为体重正常者的1.28倍(OR=1.28,P=0.027,95%CI:1.03-1.60);家庭妇女鼻腔金黄色葡萄球菌定植风险为工人与农民的1.40倍(OR=0.1.40,P=0.035,95%CI:1.02-1.91)。MRSA定植的单因素分析中,不同职业者鼻腔MRSA定植率差异有统计学意义(P=0.005)。在多因素分析中,家庭妇女鼻腔MRSA定植风险为工人与农民的2.19倍(OR=2.19,P=0.009,95%CI:1.21-3.96);有家庭成员在医疗机构工作的待产孕妇鼻腔MRSA定植风险为无家庭成员在医疗机构工作的待产孕妇的3.38倍(OR=3.38,P=0.025,95%CI:1.17-9.81)。金葡菌耐药谱分析:金葡菌耐药率最高的是青霉素(91.91%,511/556),其次为红霉素(37.23%,207/556)和妥布霉素(21.22%,118/556);MRSA菌株耐药率最高的是头孢西丁(97.54%,111/122)、红霉素(70.49%,86/122)和克林霉素(54.10%,66/122);MSSA菌株耐药率最高的是青霉素(90.32%,392/434),其次为红霉素(27.88%,121/434)和妥布霉素(21.20%,92/434)。MRSA对克林霉素、红霉素、利福平、头孢西丁和青霉素的耐药率高于MSSA且具有统计学意义(P0.05);多重耐药菌株在MRSA所占比重高于MSSA且差异具有统计学意义(P0.05);多重耐药菌株对克林霉素、红霉素、庆大霉素、莫西沙星、利奈唑胺、利福平、妥布霉素、替考拉宁、头孢西丁、青霉素和磺胺甲恶唑的耐药率均高于非多重耐药菌株且差异具有统计学意义(P0.05)。分子生物学特征:金葡菌pvl、eta、etb和tst毒素基因检出率分别为4.50%、2.70%、0.18%和2.34%。MRSA pvl基因携带率(11.48%,14/122)高于MSSA(2.53%,11/434)且有统计学意义(P0.05)。MRSA菌株在SCCmec分型中Ⅱ型、Ⅲ型和Ⅳ型分别检出率分别6.56%、10.66%和51.64%,另外有38株(31.15%)不可分型。556株金葡菌在MLST分型中发现存在84个ST型别其中ST188为主要型别(20.68%,115/556),其次为ST7(9.35%,52/556),ST6(7.73%,43/556)和ST59(7.73%,43/556)。MSSA菌株主要型别为ST188(23.73%,103/434),ST7(9.91%,43/434)和ST6(8.99%,39/434)。MRSA菌株主要型别为ST59(27.05%,33/122),其次为ST45(9.84%,12/122)、ST188(9.84%,12/122)和ST7(7.38%,9/122)。通过e BURST分析,84个ST分型属于16个国际CC克隆群(CC5、CC7、CC10、CC12、CC20、CC22、CC30、CC45、CC59、CC88、CC121、CC882、CC398、CC672、CC1719和CC2483)和5个ST型别为单体(ST1046、ST198、ST1922、ST2540和ST2990)。通过聚类分析发现,医院获得性MRSA(HA-MRSA)ST型别与社区获得性MRSA(CA-MRSA)ST型别存在聚合现象。结论深圳市龙华新区待产孕妇鼻腔金黄色葡萄球菌与MRSA的定植率较高;消瘦为鼻腔金葡菌定植的危险因素,家庭成员在医疗机构工作为鼻腔MRSA定植的危险因素,家庭妇女为鼻腔金葡菌与MRSA定植的危险因素;菌株对某些抗生素的耐药率较高,多重耐药情况较为严重;菌株毒素基因携带率较低。金葡菌ST型别复杂多样,以ST188型别为主,医院获得性MRSA与社区获得性MRSA共存且存在相互传播的风险。
[Abstract]:Objective To investigate the colonization of Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA) in pregnant women in Longhua New District of Shenzhen City, and to explore the risk factors affecting nasal colonization. Methods According to the design of cross-sectional study, the pregnant women who were admitted to Longhua Central Hospital and Guanlan People's Hospital from August 2015 to November 2015 in Longhua New District of Shenzhen City were selected by convenient sampling method. A series of laboratory standard methods were used to isolate and identify the strains; K-B paper was used to test the drug sensitivity of the isolated Staphylococcus aureus; PCR was used to detect the 16S R RNA and NUC of the characteristic genes of Staphylococcus aureus, the MEC A of MRSA and the virus carried by Staphylococcus aureus. The gene pvl, tst, eta, ETB were typed by SCCmec. The multilocus sequencing typing (MLST) was used for the ST typing of Staphylococcus aureus. _2 test or Fisher's exact probability method were used to compare the drug resistance rate of the strains. Logistic regression analysis was used for multivariate analysis. The relationship between the isolates and the international epidemic strains was analyzed by using e-BURST V3 software and dendrogram analysis software. The average age of women was 27.74 [4.69], accounting for 89.72%. Family women accounted for 25.99%. Workers and farmers accounted for 16.98%. Medical workers accounted for 1.48%. Civilian workers accounted for 35.11%. Service workers accounted for 9.34%. Persons engaged in individual and other industries accounted for 11.10%. Staphylococcus aureus and MRSA nasal colonization rate and its risk factors: 2172 adjustments. Among the subjects, 556 were Staphylococcus aureus carriers and the nasal colonization rate was 25.60%. Among them, 122 were MRSA carriers and the overall colonization rate was 5.62%. In the univariate analysis of Staphylococcus aureus colonization in nasal cavity, the relationship between BMI and Staphylococcus aureus colonization in pregnant women before pregnancy was statistically significant (P = 0.004). The risk of implantation was 1.28 times higher than that of normal weight (OR = 1.28, P = 0.027, 95% CI: 1.03-1.60); the risk of Staphylococcus aureus colonization was 1.40 times higher in housewives than that of workers and peasants (OR = 0.1.40, P = 0.035, 95% CI: 1.02-1.91). There was significant difference in the rate of MRSA colonization among different occupations (P = 0.005). In the analysis, the risk of MRSA colonization was 2.19 times that of workers and farmers (OR = 2.19, P = 0.009, 95% CI: 1.21-3.96); the risk of MRSA colonization of pregnant women with family members working in medical institutions was 3.38 times that of pregnant women without family members working in medical institutions (OR = 3.38, P = 0.025, 95% CI: 1.17-9.81). Analysis: Penicillin (91.91%, 511/556) was the highest resistance rate of Staphylococcus aureus, followed by erythromycin (37.23%, 207/556) and tobramycin (21.22%, 118/556), cefoxitin (97.54%, 111/122), erythromycin (70.49%, 86/122) and clindamycin (54.10%, 66/122), and penicillin (90.32%, 392/434) was the highest resistance rate of MSSA. The resistance rates of MRSA to clindamycin, erythromycin, rifampicin, cefoxitin and penicillin were higher than those of MSSA (P 0.05). The proportion of multidrug resistant strains in MRSA was higher than that of MSSA and the difference was statistically significant (P 0.05). Molecular biological characteristics: Staphylococcus aureus pvl, eta, ETB and TST toxin gene detection rates were 4.50%, 2.70%, respectively. MRSA PVL gene carriers (11.48%, 14/122) were higher than MSSA (2.53%, 11/434) and had statistical significance (P 0.05). The main types of MSSA were ST188 (23.73%, 103/434), ST7 (9.91%, 43/434) and ST188 (23.73%, 103/434), ST7 (9.91%, 43/434) and ST6 (8.99%, 39/434). The main types of MRSAwere ST59 (27.05%, 33/122), ST45 (7.73%, 9.84%, 12/122), ST188 (23.73%, 103/434), ST7 (9.91%, 43/434) and ST6 (8.99%, 39/434). The main types of MRSAwere ST59 (27.05%, 33/122, ST45 (7.84%, 12/122), 188 (88 (23.73%, 103/122), 188 (188 (23.73%, 103/43/434), ST7 7.38%, 9/122). By e-BURST analysis, 84 ST genotypes belonged to 16 international CC clones (CC5, CC7, CC10, CC12, CC20, CC22, CC30, CC45, CC59, CC88, CC121, CC882, CC398, CC672, CC1719 and CC2483) and 5 ST-type monomers (ST1046, ST198, ST1922, ST2540 and ST2990). Cluster analysis revealed that hospital-acquired MRSA (HA-MRSA) ST types and community-acquired MRS (CA-MRS). Conclusion The colonization rate of Staphylococcus aureus and MRSA in pregnant women waiting for delivery in Longhua New District of Shenzhen City is high, wasting is a risk factor for the colonization of Staphylococcus aureus in nasal cavity, family members working in medical institutions is a risk factor for the colonization of MRSA in nasal cavity, and family women are a risk factor for the colonization of Staphylococcus aureus and MRSA in nasal cavity. The resistance rate of S. aureus strains to some antibiotics was high, and the multidrug resistance was serious, and the carrying rate of toxin gene was low.
【学位授予单位】：广东药科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R446.5;R714

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