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首页> 外文期刊>Journal of Clinical Microbiology >Effect of temperature on transport and plating media for enteric pathogens.
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Effect of temperature on transport and plating media for enteric pathogens.

机译：温度对肠道病原体运输和铺板介质的影响。

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The effect of wide variations in incubation temperatures and long periods of incubation on transport and enrichment broths and plating media was determined by exhaustive analysis of 132 diarrheal stools for salmonellae and shigellae. Homogenized stools were streaked onto eosin methylene blue (EMB), Salmonella-Shigella (SS), and xylose lysine deoxycholate (XLD) agar plates, and into saline, Cary-Blair (CB) transport medium, and Selenite F and gram-negative (GN) enrichment broths. Incubation temperatures were compared at 20 C, 35 C, 40 C and ambient, and over a range of 4 to 52 C for media incubated in an insulated picnic cooler in an auto trunk. At 1, 2, 4, and 7 days the plates were observed, and the broths were subcultured. Each stool was streaked to 12 plates for 48 observations and pickings, and to 48 tubes, subcultured to 192 plates, for a total of 240 observations for pathogens. Analysis of data from 6,246 Salmonella-positive plates showed direct streaking to be most effective after 2 days of incubation, but broths were equally effective at 1 or 2 days. By day 4 many plates were overgrown, and both plates and broths showed diminution of positives by about 10% and at day 7, 19%. The 2,434 Shigella-positive plates were more demanding in all times and temperatures of incubation than salmonellae. Although at day 2 best results were obtained on direct streaking, shigellae die-offs in broths were excessive, with positive declining 23.7% by day 2, 49% by day 4, and 60% by day 7. Direct plating of both pathogens was poor at 20 C with about 48% success, but salmonellae preferred higher temperatures (35 and 40 C), whereas shigellae chose 35 C and ambient, which averaged 28 C for the 10-month study. Temperature was immaterial to salmonellae in broths with ambient slightly better than 35 C, but shigellae preferred 20 C and showed a 50% failure rate at 40 C, ambient being equal to 35 C. The preferential rank of broths in efficacy was GN greater than selenite greater than saline greater than CB greater than direct for salmonellae; for shigellae, GN greater than saline greater than direct greater than CB greater than selenite, with selenite proving to be unsuitable for shigellae. Plating media preferences were XLD greater than EMB greater than SS. Ten of 39 shigellae strains could not be recovered from the selenite and SS media combination, the many replications notwithstanding. The effectiveness of salmonellae and shigellae detection at ambient temperatures in Louisiana during the 10-month study period, as compared to controlled incubation temperatures, indicates that satisfactory enteric bacteriology can be done in warm climates without constant temperature incubators.
机译：通过对132个腹泻粪便中的沙门氏菌和志贺氏菌进行详尽分析，确定了孵育温度和长期孵育对转运和富集肉汤和平板培养基的影响。将均质化的粪便划线至曙红亚甲基蓝（EMB），沙门氏菌-志贺氏菌（SS）和木糖赖氨酸脱氧胆酸盐（XLD）琼脂平板上，盐水，Cary-Blair（CB）转运培养基，亚硒酸盐F和革兰氏阴性（ GN）浓缩肉汤。比较了在自动行李箱中在绝缘的野餐冷却器中培养的培养基在20°C，35°C，40°C和环境温度以及4至52°C范围内的孵育温度。在1、2、4和7天观察板，并将肉汤传代培养。将每个粪便划线至12个板以进行48次观察和采摘，并划线至48个试管，继代培养至192个板，总共240次观察病原体。对来自6,246株沙门氏菌阳性平板的数据进行的分析显示，直接划线培养2天后最有效，而肉汤在1或2天时同样有效。到第4天，许多板块都已长满，板块和肉汤的阳性率均下降了约10％，而第7天，阳性率下降了19％。 2,434志贺氏菌阳性平板在培养的所有时间和温度下均比沙门氏菌要求更高。尽管在第2天直接划线获得了最佳结果，但肉汤中志贺氏菌的死亡却过多，到第2天，阳性菌落下降23.7％，到第4天，下降49％，到第7天下降60％。温度为20℃时，成功率约为48％，但沙门氏菌更喜欢较高的温度（35和40℃），而志贺氏菌则选择35℃和环境温度，在10个月的研究中平均为28℃。温度对环境中略高于35 C的肉汤中的沙门氏菌无关紧要，但志贺氏菌优选20 C，并在40 C时显示50％的失败率，环境等于35C。沙门氏菌大于生理盐水大于CB大于直接沙门氏菌;对于志贺氏菌，GN大于盐水大于直接大于CB大于亚硒酸盐，亚硒酸盐被证明不适合于志贺氏菌。电镀介质首选项XLD大于EMB大于SS。尽管有许多重复，仍无法从亚硒酸盐和SS培养基组合中回收到39个志贺氏菌菌株中的10个。在10个月的研究期内，路易斯安那州在环境温度下沙门氏菌和志贺氏菌检测的有效性与受控的孵化温度相比，表明在温暖的气候中无需恒温培养箱即可完成令人满意的肠细菌学。

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