Superbug stars in media-made epidemic

Emergence of potential superbug mycobacterium tuberculosis, lessons from new delhi mutant-1 bacterial strains

Recent reports have shown that certain bacterial strains attain the New Delhi Metallo-beta-lactamase-1 (NDM-1) enzyme and become resistant to a broad range of antibiotics. Similarly, more dangerous "superbugs" of multi-drug resistant (MDR) and extensive drug resistant (XDR) Mycobacterium tuberculosis strains are gradually emerging through rapid genetic mutation caused by prescription non-compliance or unsupervised indiscriminate use of anti-tubercular drugs or other antibiotics. Mycobacterium tuberculosis cases have been reported in highly susceptible population groups including the aboriginal communities of US and Canada. In Canada alone, the total number of reported tuberculosis cases has decreased over the past decade. However, there is a steady increase in HIV cases in certain communities including the aboriginal communities. Reintroduction of MDR/XDR strains of tuberculosis is possible in these susceptible communities, which in turn may pose serious public health situation. MDR/XDR strains of tuberculosis are virtually untreatable using current anti-tubercular medication protocols. Thus, MDR/XDR tuberculosis presents a grave global public health threat. The unpredictable genetic mechanism involved in generating MDR/XDR resistant strains of Mycobacterium tuberculosis may pose greater challenges in developing appropriate treatment strategies. In this article, we briefly review potential genetic mechanism of emerging NDM-1 bacterial strains and draw a rationale parallel to the underlying genetic mechanism of MDR/XDR Mycobacterium tuberculosis strain development.

Fatal necrotising fasciitis and myositis in a cat associated with Streptococcus canis

Necrotising fasciitis and necrotising myositis are rare but serious life threatening conditions reported mainly in human beings and dogs. Most cases to date have been caused by beta-haemolytic streptococci of Lancefield groups A, B, C or G. Necrotising fasciitis has been reported only twice in cats and necrotising myositis has never been described. This paper describes a fatal case of necrotising fasciitis and myositis with pneumonia and septicaemia in a nine-year-old cat. The cat had been undergoing treatment for a suspected tear of the cranial cruciate ligament, but on the seventh day of treatment it suddenly deteriorated and died. On postmortem examination, there was an area of hair loss from its left hindlimb and discoloration of the underlying fascia and biceps femoris muscle. Severe necrotising fasciitis and myositis, with numerous intralesional Gram-positive coccoid bacteria, was diagnosed histologically. Other findings included necrotising pneumonia, pleuritis, focal encephalitis, myocarditis and nephritis. Culture of the affected tissues yielded a pure, heavy growth of Streptococcus canis.

Necrotizing fasciitis: analysis of 48 cases in South Auckland, New Zealand

BACKGROUND

To assess the presentation, management and risk factors for mortality in necrotizing fasciitis at Middlemore Hospital in South Auckland, New Zealand.

METHODS

A retrospective review of the medical records of patients presenting to Middlemore Hospital over a 6-year period (1997-2002) with a diagnosis of necrotizing fasciitis.

RESULTS

Forty eight patients were identified. There were 27 men and 21 women whose age ranged from 19 to 80 years (median 51 years) at presentation. Maori and Pacific Islanders accounted for 64% of total admissions despite making up only 31% of the referral population. Streptococcus Pyogenes was the most common bacterial isolate (54%). 31% of patients had polymicrobial infections. Sixty-two per cent of cases involved extremities. The median number of operations and length of stay were 4 and 31 days, respectively. Overall mortality was 29%. In multivariate analysis, delay in surgical intervention (P = 0.015) and diabetes mellitus (P = 0.023) were found to be associated with increased mortality. Ethnicity, sex, type of pathogen, site of infection and increasing age did not affect mortality.

CONCLUSION

Necrotizing fasciitis remains a significant problem in our community especially in the Maori and Pacific population. Early surgical debridement decreases mortality rates.

Anesthetic implications of cervicofacial necrotizing fasciitis

Cervicofacial necrotizing fasciitis is a necrotizing soft tissue infection of face and neck spreading at the level of fascia. It has been described as a putrid ulcer, phagedaena, and hospital gangrene. It has a high mortality rate, and presents a challenge to anesthesiologists who must secure an airway to deliver anesthesia safely. We report a case of cervicofacial necrotizing fasciitis in which the patient underwent repeated radical surgical debridement of face and neck, including a mandibulectomy. These critically ill patients often present with sepsis and multiple system organ failure. Extensive preoperative evaluation, invasive monitoring, and possibly the use of vasopressors and inotropes are essential in treating these patients. The tracheas of these patients should remain intubated after initial debridement. Tracheostomy should be performed early. Antibiotic therapy, nutritional support, early debridement, and hyperbaric oxygen therapy all help to decrease mortality in these patients.

[Necrotizing fasciitis caused by group A streptococcus]

The first case of the confirmed necrotizing fasciitis caused by Group A Streptococcus in Yugoslavia was presented. Male patient, aged 28, in good health, suddenly developed symptoms and signs of severe infective syndrome and intensive pain in the axillary region. Parenteral antibiotic, substitutional and supportive therapy was conducted along with the radical surgical excision of the necrotizing tissue. The patient did not develop streptococcal toxic shock syndrome thanks to the early established diagnosis and timely applied aggressive treatment. He was released from the hospital as completely cured two months after the admission.

A cluster of cases of streptococcal necrotizing fasciitis in Gloucestershire

We describe the first cluster of cases of necrotizing fasciitis (NF) in this century in the United Kingdom (UK). Between 1 January and 30 June 1994 there were six cases (five confirmed, one probable) of Streptococcus pyogenes NF in west Gloucestershire, population 320,000. Two cases died. The first two patients probably acquired their infections during the course of elective surgery performed in the same operating theatre, possibly from a nasopharyngeal carrier amongst the theatre staff. The remaining infections were community-acquired. Of 5 S. pyogenes isolates there were 2 M1 strains, 1 M3, 1 M5 and 1 M non-typeable strain. S. pyogenes NF had not been recorded in west Gloucestershire in the preceding 10 years and the incidence of S. pyogenes bacteraemia in England and Wales had not risen in the past 5 years. The two presumably theatre-acquired infections raised several issues. The need for detailed bacteriological investigation of all cases of post-surgical NF was confirmed. Clusters of S. pyogenes infection following surgery should be managed by closure of the operating theatre until all staff have been screened for carriage. Closure of an operating theatre and screening of staff following a sporadic case is probably not justified because of the infrequency of surgical cross-infection with S. pyogenes. Regular, routine screening of theatre staff is neither practical nor necessary.