Translating bacterial molecular epidemiology into information to improve infectious disease risk assessment and control

肺炎链球菌（肺炎球菌）和B族链球菌（GBS）是重要的致病菌，在婴幼儿、老年人和某些慢性病患者中引起败血症和脑膜炎。两者都由许多不同的类型组成，其中一些类型比其他类型更容易引起疾病。在澳大利亚，预防最常见致病类型的肺炎球菌疫苗用于风险最高的人群。抗生素耐药性是一个日益严重的问题，应该通过免疫接种来部分抵消。在分娩期间给患有GBS的妇女使用抗生素可以降低新生儿的感染率，但这种方法有许多缺点，包括增加抗生素耐药性的风险。针对GBS的疫苗尚未可用。我们已经开发出识别这些细菌详细指纹的方法，使我们能够识别类型、抗生素耐药性，以及GBS的其他特征，这些特征可以将高致病性菌株与大多数无害且不太可能引起疾病的菌株区分开来。这些方法仍然非常缓慢和昂贵，并且产生复杂的模式，难以快速解释。我们计划为这些细菌开发一种新的、快速的、相对便宜的指纹识别系统，并用计算机程序来分析和解释结果。它们将使我们能够检查导致疾病的肺炎球菌菌株，以确保未被疫苗覆盖的新菌株不会变得更加普遍，从而降低疫苗的有效性，并且抗生素耐药性不会进一步增加。这些方法还将使我们能够研究引起新生儿感染的一小部分GBS菌株与由孕妇无害携带并且对其婴儿风险很小的大多数GBS菌株之间的差异。最终，这将使医生能够识别出婴儿风险最大的女性，减少不必要的抗生素使用。

Streptococcus pneumoniae (pneumococcus) and group B streptococcus (GBS) are important pathogenic bacteria, which cause septicaemia and meningitis in young infants, the elderly and people with certain chronic diseases. Both consist of a number of different types, some of which are more likely to cause disease than others. Pneumococcal vaccines that protect against the commonest pathogenic types are used in Australia in people most at risk.Antibiotic resistance is an increasing problem, which should be partly off-set by immunisation. Giving antibiotics during labour, to women colonised with GBS, can reduce infection rates in newborns, but there are many disadvantages of this approach, including the risk of increased antibiotic resistance. Vaccines against GBS are mpt yet available. We have developed methods to identify detailed fingerprints of these bacteria which allow us to identify types, antibiotic resistance and, for GBS, other characteristics which can distinguish highly pathogenic strains from the majority that are carried harmlessly and unlikely to cause disease. The methods are still quite slow and expensive and produce complex patterns,which are difficult to interpret rapidly. We plan to develop a new, rapid and relatively inexpensive, fingerprinting system for these bacteria and computer programs to analyse and interpret the results. They will allow us to check the strains of pneumococci that cause disease to make sure that new ones, not covered by the vaccine, do not become more common and reduce the effectiveness of vaccine and that antibiotic resistance does not increase further. The methods will also allow us to study differences between the small proportion of GBS strains that cause neonatal infection and the majority that are carried harmlessly by pregnant women and are of little risk to their babies. Eventually this should allow doctors to identify women whose babies are most at risk, reduce unnecessary antibiotic use.