达托霉素（Daptomycin）是一种广谱抗生素，常用于治疗多种感染疾病。然而，尽管其广泛应用于治疗细菌感染，达托霉素并不适用于治疗左侧心内膜炎（left-sided infective endocarditis）。这是因为达托霉素在治疗该病时存在一些限制和挑战。

首先，左侧心内膜炎是一种严重的感染性疾病，通常由革兰阳性链球菌引起。这些菌株通常对β-内酰胺类抗生素高度敏感，如青霉素和万古霉素。然而，达托霉素并不能有效抵抗这些菌株，因为它只对革兰阳性细菌具有活性。因此，达托霉素在治疗左侧心内膜炎时，并不能达到预期的疗效。

其次，达托霉素对心瓣膜和纤维素物质的覆盖能力有限。在左侧心内膜炎中，细菌会附着在心瓣膜表面，并形成病理性的结节。由于达托霉素无法覆盖这些结节，它对治疗该病的有效性受到了限制。

此外，达托霉素还可能出现耐药性问题。当细菌暴露在达托霉素中时，它们可能会逐渐产生耐药性。这意味着达托霉素在治疗左侧心内膜炎时可能会失去其原有的疗效。因此，在选择治疗方案时，医生通常会优先考虑其他更有效的抗生素。

尽管达托霉素不能用于治疗左侧心内膜炎，但它在其他感染疾病的治疗中具有一定的优势。它广谱的抗菌活性使其成为抗生素治疗中的重要组成部分。然而，对于左侧心内膜炎的治疗，我们需要选择其他抗生素，特别是对革兰阳性链球菌具有较高敏感性的药物。

In English:

Daptomycin, a broad-spectrum antibiotic commonly used to treat various infections, is not suitable for the treatment of left-sided infective endocarditis. This is due to certain limitations and challenges associated with the use of daptomycin in treating this particular condition.

Firstly, left-sided infective endocarditis is a severe infectious disease typically caused by gram-positive streptococci. These strains are usually highly susceptible to β-lactam antibiotics such as penicillin and vancomycin. However, daptomycin is not effective against these strains as it only exhibits activity against gram-positive bacteria. Therefore, daptomycin fails to achieve the desired therapeutic effect in the treatment of left-sided infective endocarditis.

Secondly, daptomycin has limited coverage on valve and fibrin material. In left-sided infective endocarditis, bacteria adhere to the surface of heart valves and form pathological vegetations. Daptomycin's inability to cover these vegetations restricts its effectiveness in treating the disease.

Furthermore, daptomycin may encounter issues with resistance. When bacteria are exposed to daptomycin, they may gradually develop resistance to the antibiotic. This implies that daptomycin may lose its original efficacy in the treatment of left-sided infective endocarditis. Consequently, other more effective antibiotics are typically prioritized when selecting treatment options.

Despite its incompatibility for left-sided infective endocarditis, daptomycin holds certain advantages in the treatment of other infectious diseases. Its broad-spectrum antimicrobial activity makes it an important component of antibiotic therapy. However, for the treatment of left-sided infective endocarditis, alternative antibiotics, particularly those with higher sensitivity to gram-positive streptococci, need to be considered.