Background The isolation of S. pneumoniae (Sp) depends on specimen integrity / transport, media and expertise. The non-availability of sheep blood agar poses a challenge in identification of colonial morphology and identification in India. Methods Laboratories processed swabs containing either pure Sp or Sp in mixed cultures with a second (confounding) bacterium shipped across the country in cold conditions. Duplicate set of swabs was shipped back to the central laboratory to assess the impact of shipping on culture viability. The identical swab was cultured on sheep, human blood and one additional agar plate used in the laboratory. Results 46/60(77%) of cultures containing only Sp were correctly identified. In specimens where Sp was present in mixed culture, the proportion of isolates in which Sp was correctly identified varied, with most variability attributed to the particular confounding organism rather than the media. There was no discernible impact of temperature-controlled (4-6°C) transport on the isolation of Sp from culture swabs. Conclusions The study clearly elucidates the ability of laboratories for isolation of S. pneumoniae on human blood agar in resource limited settings. The results highlight the difficulties inherent in correctly identifying pathogens in mixed cultures in needs improvement using standardized tests across the study centers. The study also reaffirms the ability to transport biological specimens over long geographical distances without loss.

中文翻译：

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通过在印度实验室之间使用替代的血液补充培养基来源来进行肺炎链球菌的跨国运输以及分离和鉴定。


背景 肺炎链球菌 (Sp) 的分离取决于样本的完整性/运输、培养基和专业知识。羊血琼脂的缺乏给印度的菌落形态和鉴定带来了挑战。方法 实验室处理含有纯 Sp 或 Sp 与第二种（混杂）细菌混合培养物的拭子，并在寒冷条件下运往全国各地。将重复的拭子组运回中心实验室，以评估运输对培养物活力的影响。同样的拭子在绵羊、人血和实验室使用的另一块琼脂板上进行培养。结果 46/60（77%）仅含有 Sp 的培养物被正确鉴定。在混合培养物中存在 Sp 的标本中，正确鉴定 Sp 的分离株比例各不相同，其中大多数变异归因于特定的混杂生物体而不是培养基。温度控制 (4-6°C) 运输对从培养拭子中分离 Sp 没有明显影响。结论 该研究清楚地阐明了实验室在资源有限的环境中在人血琼脂上分离肺炎链球菌的能力。结果凸显了在混合培养物中正确识别病原体所固有的困难，需要在研究中心使用标准化测试进行改进。该研究还重申了长距离运输生物样本而不会丢失的能力。