Serratia, particularly Serratia marcescens, is a gram-negative, facultative anaerobic bacillus that is commonly associated with nosocomial infections. Though more frequently linked with urinary and respiratory tract infections, Serratia is a notable pathogen in skin and skin structure infections (SSSIs), especially in immunocompromised patients or those with indwelling devices. Its ability to produce biofilms and exhibit
Providencia species, particularly Providencia stuartii and Providencia rettgeri, are gram-negative, facultatively anaerobic bacilli belonging to the Enterobacteriaceae family. While more commonly implicated in urinary tract infections, Providencia has emerged as an opportunistic pathogen in healthcare-associated skin and skin structure infections (SSSIs), especially among elderly or immunocompromised patients. These organisms are frequently isolated in polymicrobial chronic
Proteus species, particularly Proteus mirabilis and Proteus vulgaris, are facultatively anaerobic gram-negative bacilli belonging to the Enterobacteriaceae family. While commonly residing in the gastrointestinal tract, these organisms can become opportunistic pathogens in skin and soft tissue infections (SSSIs), particularly when normal barriers are compromised. Their motility (via peritrichous flagella) and urease activity contribute to their
Peptostreptococcus is a genus of anaerobic, gram-positive cocci that forms part of the normal microbial flora of the skin, mucous membranes, and gastrointestinal tract. While typically harmless in commensal populations, these bacteria become pathogenic when introduced into sterile tissue via trauma, surgery, or compromised host immunity. Skin and skin structure infections (SSSIs) involving Peptostreptococcus are
Peptococcus species are gram-positive, obligate anaerobic cocci that form part of the normal human flora, particularly in the gastrointestinal and genitourinary tracts. Although generally considered non-pathogenic, under certain conditions such as immunosuppression, trauma, or surgical intervention, Peptococcus can become opportunistic, leading to serious skin and skin structure infections (SSSIs). Pathophysiology of Peptococcus in Soft Tissue
Morganella morganii is a facultative anaerobic, gram-negative bacillus belonging to the Enterobacteriaceae family. Though traditionally considered an opportunistic pathogen, it has emerged as a significant cause of skin and skin structure infections (SSSIs), particularly in immunocompromised individuals, surgical patients, and those with chronic wounds. Its increasing resistance profile adds complexity to clinical management. Microbiological Characteristics
Klebsiella species, primarily Klebsiella pneumoniae, are gram-negative bacilli associated with healthcare-associated infections and opportunistic community-acquired cases. While most commonly implicated in urinary tract and respiratory infections, Klebsiella can also cause severe skin and skin structure infections (SSSIs), especially in immunocompromised or hospitalized individuals. Pathogenesis of Klebsiella in Skin and Soft Tissue Klebsiella species possess virulence
Skin and skin structure infections (SSSIs) encompass a wide spectrum of bacterial infections involving the epidermis, dermis, subcutaneous tissue, fascia, and muscle. These infections vary in severity from mild superficial conditions to life-threatening necrotizing fasciitis. Accurate classification and prompt intervention are vital to minimizing complications and ensuring effective treatment. Classification of SSSIs Based on Severity
Fusobacterium species are obligate anaerobic, gram-negative bacilli commonly found in the oropharynx, gastrointestinal tract, and genitourinary system. Though often commensal, these bacteria can cause severe infections under the right conditions, particularly when the skin barrier is compromised. Among soft tissue pathogens, Fusobacterium necrophorum and Fusobacterium nucleatum are notable for their involvement in necrotic skin and
Enterococcus species, primarily Enterococcus faecalis and Enterococcus faecium, are gram-positive, facultative anaerobic cocci that commonly inhabit the gastrointestinal tract. Although often considered low-virulence organisms, they have emerged as significant nosocomial pathogens, particularly in skin and skin structure infections (SSSIs), where their intrinsic resistance and capacity to acquire new resistance genes complicate treatment. Pathogenesis of Enterococcus