Vibrio damsela wound infections in Australia

Photobacterium damselae subsp. damselae bacteraemia in a patient with liver cirrhosis

Photobacterium damselae subsp. damselae is a family of Vibrionaceae and exists in the marine environment. The organism rarely causes soft-tissue infection in humans; moreover, most of the infected individuals have a history of fishing or exposure to brackish water. We experienced the case of a 63-year-old patient with a history of liver cirrhosis (Child-Pugh class B) who presented with a fever and swelling of the left leg with pain. His symptoms developed after fishing and eating raw fish with exposure of brackish water. He was diagnosed with cellulitis, and Photobacterium damselae spp. damselae was detected in blood culture. The patient was treated with ceftazidime and minocycline and he was discharged after recovery. We need to be aware that in immunocompromised patients with cellulitis exposed to brackish water, organisms other than Staphylococci and Streptococci may be the causative organisms.

Photobacterium damselae subsp. damselae, a bacterium pathogenic for marine animals and humans

Photobacterium damselae subsp. damselae (formerly Vibrio damsela) is a pathogen of a variety of marine animals including fish, crustaceans, molluscs, and cetaceans. In humans, it can cause opportunistic infections that may evolve into necrotizing fasciitis with fatal outcome. Although the genetic basis of virulence in this bacterium is not completely elucidated, recent findings demonstrate that the phospholipase-D Dly (damselysin) and the pore-forming toxins HlyA_pl and HlyA_ch play a main role in virulence for homeotherms and poikilotherms. The acquisition of the virulence plasmid pPHDD1 that encodes Dly and HlyA_pl has likely constituted a main driving force in the evolution of a highly hemolytic lineage within the subspecies. Interestingly, strains that naturally lack pPHDD1 show a strong pathogenic potential for a variety of fish species, indicating the existence of yet uncharacterized virulence factors. Future and deep analysis of the complete genome sequence of Photobacterium damselae subsp. damselae will surely provide a clearer picture of the virulence factors employed by this bacterium to cause disease in such a varied range of hosts.

Complicated skin and soft tissue infection

Skin and soft tissue infections (SSTIs) are common, and complicated SSTIs (cSSTIs) are the more extreme end of this clinical spectrum, encompassing a range of clinical presentations such as deep-seated infection, a requirement for surgical intervention, the presence of systemic signs of sepsis, the presence of complicating co-morbidities, accompanying neutropenia, accompanying ischaemia, tissue necrosis, burns and bites. Staphylococcus aureus is the commonest cause of SSTI across all continents, although its epidemiology in terms of causative strains and antibiotic susceptibility can no longer be predicted with accuracy. The epidemiology of community-acquired and healthcare-acquired strains is constantly shifting and this presents challenges in the choice of empirical antibiotic therapy. Toxin production, particularly with Panton-Valentine leucocidin, may complicate the presentation still further. Polymicrobial infection with Gram-positive and Gram-negative organisms and anaerobes may occur in infections approximating the rectum or genital tract and in diabetic foot infections and burns. Successful management of cSSTI involves prompt recognition, timely surgical debridement or drainage, resuscitation if required and appropriate antibiotic therapy. The mainstays of treatment are the penicillins, cephalosporins, clindamycin and co-trimoxazole. β-Lactam/β-lactamase inhibitor combinations are indicated for polymicrobial infection. A range of new agents for the treatment of methicillin-resistant S. aureus infections have compared favourably with the glycopeptides and some have distinct pharmacokinetic advantages. These include linezolid, daptomycin and tigecycline. The latter and fluoroquinolones with enhanced anti-Gram-positive activity such as moxifloxacin are better suited for polymicrobial infection.

Skin and soft tissue infection: microbiology and epidemiology

Skin and soft tissue infections (SSTIs) are common and range in severity from minor, self-limiting, superficial infections to life-threatening diseases requiring all the resources of modern medicine. The classification of SSTIs can be based on the anatomical site, clinical severity or microbial cause, but some classifications divide SSTIs into complicated and uncomplicated infections. Community-acquired SSTIs are most commonly caused by staphylococci or streptococci, but almost any organism is capable of causing inflammation within soft tissue. Recent epidemiological trends have shown an increase not only in healthcare-associated meticillin-resistant Staphylococcus aureus (MRSA), but also in MRSA acquired in the community. Many of the latter strains produce exotoxins and are epidemiologically distinct from healthcare-acquired strains. Factors that may affect the microbial cause include underlying disease such as diabetes or immune dysfunction; hospital attendance, injecting drug use, travel, animal contact and environmental contamination.

Vibrio vulnificus and V. parahaemolyticus necrotising fasciitis in fishermen visiting an estuarine tropical northern Australian location

Three cases of severe necrotising fasciitis due to Vibrio vulnificus (two cases) and Vibrio parahaemolyticus (one case, fatal), have occurred in Caucasian tourists while fishing at a remote tropical northern Australian estuarine area. Infections were acquired over a 4-year period during the tourist fishing season (April to July 2000-2003), when water temperatures range from 23 to 30 degrees C. They are notable for their geographical clustering in the remote western aspect of the Gulf of Carpentaria, an area characterised by sedimentary stratiform zinc-lead-silver deposits and a major mining operation. Patients presented with classical bullous cellulitis with necrotising fasciitis, accompanied by severe sepsis. Underlying risk factors were identified in each patient; in one instance, previously unrecognised haemochromatosis was diagnosed. Likely reasons for Vibrio occurrence in this particular ecological niche are discussed.

Fatal Infection of the Hand Due toPhotobacterium damsela:A Case Report

We report a case of fatal acute renal failure due to Photobacterium damsela infection of the hand. Although the patient received intensive medical care and surgical treatment, he died 8 h after arrival at the hospital. This is the first case of P. damsela sepsis proven by blood culture in Japan.

Topically acquired bacterial zoonoses from fish: a review

The main pathogens acquired topically from fish (through spine puncture or open wounds) are Aeromonas hydrophila, Edwardsiella tarda, Erysipelothrix rhusiopathiae, Mycobacterium marinum, Streptococcus iniae, Vibrio vulnificus and Vibrio damsela. S. iniae has recently emerged as a public health hazard associated with aquaculture, and M. marinum often infects home aquarium hobbyists. With the expansion of aquaculture and popularity of recreational fishing in Australia, medical practitioners can expect to see more infections of this nature. Diagnosis and treatment may be difficult, especially in view of emerging antibiotic resistance in fish pathogens.