Yeh Pamela J, Simon Dawn M, Millar Jess A, Alexander H Forrest, Franklin Darleen
Department of Biology, Portland State University, Portland, Oregon, USA. ; Department of Environmental Health Sciences, School of Public Health, UCLA, Los Angeles, California, USA.
Osong Public Health Res Perspect. 2011 Dec;2(3):202-9. doi: 10.1016/j.phrp.2011.11.047.
Our goal was to determine the diversity and abundance of Staphylococcus bacteria on different components of a public transportation system in a mid-sized US city (Portland, Oregon) and to examine the level of drug resistance in these bacteria.
We collected 70 samples from 2 cm × 4 cm sections from seven different areas on buses and trains in Portland, USA, taking 10 samples from each area. We isolated a subset of 14 suspected Staphylococcus spp. colonies based on phenotype, and constructed a phylogeny from16S rRNA sequences to assist in identification. We used the Kirbye-Bauer disk diffusion method to determine resistance levels to six common antibiotics.
We found a range of pathogenic Staphylococcus species. The mean bacterial colony counts were 97.1 on bus and train floors, 80.1 in cloth seats, 9.5 on handrails, 8.6 on seats and armrests at bus stops, 3.8 on the underside of seats, 2.2 on windows, and 1.8 on vinyl seats per 8 cm(2) sample area. These differences were significant (p < 0.001). Of the 14 isolates sequenced, 11 were staphylococci, and of these, five were resistant to penicillin and ampicillin, while only two displayed intermediate resistance to bacitracin. All 11 isolates were sensitive to trimethoprim-sulfamethoxazole, vancomycin, and tetracycline.
We found six different strains of Staphylococcus, and while there were varying levels of drug resistance, we did not find extensive levels of multidrug-resistant bacteria, and no S. aureus was found. We found floors and cloth seats to be areas on buses and trains that showed particularly high levels of bacteria.
我们的目标是确定美国一个中等规模城市（俄勒冈州波特兰市）公共交通系统不同部件上葡萄球菌的多样性和丰度，并检测这些细菌的耐药水平。
我们从美国波特兰市公交车和火车上七个不同区域的2厘米×4厘米切片中采集了70个样本，每个区域采集10个样本。我们根据表型分离出14个疑似葡萄球菌属菌落的子集，并从16S rRNA序列构建系统发育树以协助鉴定。我们使用Kirbye-Bauer纸片扩散法确定对六种常用抗生素的耐药水平。
我们发现了一系列致病性葡萄球菌种类。每8平方厘米样本区域的平均细菌菌落数在公交车和火车地板上为97.1，在布质座椅上为80.1，在扶手上为9.5，在公交站的座椅和扶手上为8.6，在座椅下方为3.8，在窗户上为2.2，在乙烯基座椅上为1.8。这些差异具有统计学意义（p < 0.001）。在测序的14个分离株中，11个是葡萄球菌，其中5个对青霉素和氨苄青霉素耐药，而只有2个对杆菌肽表现出中度耐药。所有11个分离株对甲氧苄啶-磺胺甲恶唑、万古霉素和四环素敏感。
我们发现了六种不同的葡萄球菌菌株，虽然存在不同程度的耐药性，但我们没有发现广泛的多重耐药细菌，也没有发现金黄色葡萄球菌。我们发现公交车和火车上的地板和布质座椅是细菌含量特别高的区域。
