Rossolini Gian Maria, Stefani Stefania
Dipartimento di Biologia Molecolare, Sezione di Microbiologia Università degli Studi di Siena, Italy.
Infez Med. 2009 Sep;17 Suppl 4:18-29.
Skin and soft tissue infections (SSTI) are common and, generally, uncomplicated at the time of initial presentation. However, these infections can worsen quickly when there are delays in diagnosis and treatment. The clinical presentation of most SSTI is the culmination of a microbial three-step process as follow: i) bacterial adherence to host cells; ii) invasion of tissue with evasion of host defences, and iii) elaboration of toxins. Even if the microbiology of wounds has been actively investigated in recent years, there is still much to be learned about the microbial mechanisms that induce infection and prevent wound healing. There are also several means by which bacteria penetrate the skin barrier. The most common route is through a break in the barrier (lacerations, bite wounds, scratches, instrumentations, pre-existing skin conditions, wounds or ulcers, burns and surgery); other routes of penetration include contiguous spread from adjacent infections (e.g. osteomyelitis), entry of water into the skin pores, and, rarely, haematogenous seeding (i.e septic emboli). From what it was said, many microorganisms, above all from the normal skin microbiota, can be involved in these often polymicrobial infections, with Gram-positives such as Staphylococcus aureus, Streptococcus pyogenes, Staphylococcus epidermidis, Corynebacterium spp being predominant. Many other aerobic and anaerobic species, including Gram-negative bacilli, can also be involved. Even if the diagnosis of most SSTI is based on clinical examination, laboratory investigations, guided by clinical information, can help to confirm the diagnosis and elucidate the characteristics of specific pathogens. These microbiological investigations may include blood cultures, tissue swabs with culture, and needle aspiration. In rapidly progressing infections, empirical therapy is essential, although microbiological data are important in confirming subsequently that the chosen regimen is appropriate. Furthermore, the number of microorganisms becoming resistant to many usual drugs and the changing microbial epidemiology of these infections, such as the emergence of CA-MRSA, required a constant cooperation between the microbiology lab and the clinician in order to address microbiological aspects that can be critical to the successful management of SSTI.
皮肤和软组织感染（SSTI）很常见，通常在初次就诊时并不复杂。然而，当诊断和治疗出现延误时，这些感染可能会迅速恶化。大多数SSTI的临床表现是一个微生物三步过程的结果，如下所示：i）细菌粘附于宿主细胞；ii）入侵组织并逃避宿主防御，以及iii）产生毒素。尽管近年来对伤口微生物学进行了积极研究，但关于诱导感染和阻止伤口愈合的微生物机制仍有很多需要了解的地方。细菌穿透皮肤屏障也有几种方式。最常见的途径是通过屏障破损处（撕裂伤、咬伤、抓伤、器械操作、既往皮肤状况、伤口或溃疡、烧伤和手术）；其他穿透途径包括从相邻感染（如骨髓炎）的连续扩散、水进入皮肤毛孔，以及很少见的血行播散（即脓毒性栓子）。综上所述，许多微生物，尤其是正常皮肤微生物群中的微生物，可能参与这些通常为多微生物的感染，其中革兰氏阳性菌如金黄色葡萄球菌、化脓性链球菌、表皮葡萄球菌、棒状杆菌属占主导地位。许多其他需氧和厌氧菌种，包括革兰氏阴性杆菌，也可能参与其中。尽管大多数SSTI的诊断基于临床检查，但在临床信息的指导下，实验室检查有助于确诊并阐明特定病原体的特征。这些微生物学检查可能包括血培养、组织拭子培养和针吸活检。在快速进展的感染中，经验性治疗至关重要，尽管微生物学数据对于随后确认所选治疗方案是否合适很重要。此外，对许多常用药物产生耐药性的微生物数量以及这些感染不断变化的微生物流行病学，如社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）的出现，要求微生物实验室和临床医生不断合作，以解决对SSTI成功管理可能至关重要的微生物学问题。
