Biologically Active Substances from Marine Hydrobionts with Antibacterial Activity in Composition of New Wound Dressings

The data on the experimental study of the efficacy of the gel wound dressings based on chitosan and calcium alginate containing bioactive substances from marine hydrobionts with complex therapeutic action (sulfated polysaccharides from brown algae, hydrolyzed bivalves, peptides from nerve ganglia of cephalopods) are described. The model of thermal burns complicated by Staphylococcus aureus infection was used. Planimetric and bacteriological investigations revealed pronounced wound healing and antibacterial effects of the gel coating. The gel containing sulfated polysaccharides from brown algae showed the highest wound healing activity.

Mandatory infectious diseases consultation for MRSA bacteremia is associated with reduced mortality

OBJECTIVES

Although infectious disease (ID) consultation has been associated with lower mortality in Staphylococcus aureus bloodstream infections, it is still not mandatory in many centers. This study aimed at assessing the impact of ID consultation on diagnostic and therapeutic management of methicillin-resistant S. aureus (MRSA) bacteremia.

METHODS

Retrospective cohort study of all patients with MRSA bacteremia from 2001 to 2010. ID consultations were obtained on request between 2001 and 2006 and became mandatory since 2007.

RESULTS

156 episodes of MRSA bacteremia were included, mostly from central venous catheter (32%) and skin and soft tissue (19%) infections. ID consultation coverage was 58% between 2001 and 2006 and 91% between 2007 and 2010. ID consultation was associated with more echocardiography (59% vs. 26%, p < 0.01), vancomycin trough level measurements (99% vs. 77%, p < 0.01), follow-up blood cultures (71% vs. 50%, p = 0.05), deep-seated infections (43% vs. 16%, p < 0.01), more frequent infection source control (83% vs. 57%, p = 0.03), a longer duration of MRSA-active therapy (median and IQR: 17 days, 13-30, vs. 12, 3-14, p < 0.01) and a 20% reduction in 7-day, 30-day and in-hospital mortality.

CONCLUSIONS

ID consultation was associated with a better management of patients with MRSA bacteremia and a reduced mortality.

Toxic epidermal necrolysis: Part II. Prognosis, sequelae, diagnosis, differential diagnosis, prevention, and treatment

Toxic epidermal necrolysis (TEN) is a life-threatening, typically drug-induced, mucocutaneous disease. TEN has a high mortality rate, making early diagnosis and treatment of paramount importance. New but experimental diagnostic tools that measure serum granulysin and high-mobility group protein B1 (HMGB1) offer the potential to differentiate early TEN from other, less serious drug reactions, but these tests have not been validated and are not readily available. The mainstay of treatment for TEN involves discontinuation of the offending drug, specialized care in an intensive care unit or burn center, and supportive therapy. Pharmacogenetic studies have clearly established a link between human leukocyte antigen allotype and TEN. Human leukocyte antigen testing should be performed on patients of East Asian descent before the initiation of carbamezapine and on all patients before the initiation of abacavir. The effectiveness of systemic steroids, intravenous immunoglobulins, plasmapheresis, cyclosporine, biologics, and other agents is uncertain.

[Molecular epidemiology of Panton-Valentine leukocidin (PVL) -positive Staphylococcus aureus associated with skin and soft tissue infection]

Panton-Valentine leukocidin (PVL) secreted by Staphylococcus aureus is known to cause severe skin, soft tissue and lung infections. To assess the prevalence and genetic characteristics of PVL-positive S. aureus in our hospital, we investigated 86 S. aureus isolates isolated from skin and soft tissue pus between September 2011 and May 2012 at Daisan Hospital, the Jikei University School of Medicine (Tokyo, Japan). All isolates were investigated for the mecA gene and PVL gene by PCR amplification. The MRSA isolates confirmed were genotyped using SCCmec typing. PVL-gene positive isolates confirmed by the PVL-RPLA (reverse passive latex agglutination) assay were characterized by agr typing and multilocus sequence typing (MLST). Overall 6 (3 MSSA isolates and 3 MRSA isolates) PVL-positive strains (7.0%) were detected. The PVL prevalence was 11.1% in MRSA and 5.1% in MSSA. PVL-positive strains were isolated from young adults (range: 8-47 years) outpatient. Patients infected with PVL-positive MRSA were significantly younger than those infected with PVL-negative MRSA(32 and 68 years, respectively; P = 0.009, t-test). The 6 PVL positive strains were assigned by the MLST to 6 STs that were prevalent among PVL-positive strains. The SCCmec type of the PVL-positive MRSA were classified into 2 types (type IV or V) that were generally characteristic of CA-MRSA. Our data are consistent with some previous reports showing that PVL gene is found in certain ST strains. The PVL-positive strain must be taken into account when S. aureus is isolated from young adult SSTI.

The evaluation of nosocomial infection during 1-year-period in the burn unit of a training hospital in Istanbul, Turkey

An analysis of the burned patients, admitted to our eight bed burn unit and treated between 1 January and 31 December 2000, was performed. Prevalence, etiologic agents, length of hospitalization, cost of treatment and mortality rates caused by nosocomial infections (NIs) were studied. The study included 63 patients. Eighteen of these (Group-A) had 24 NI episodes. The most common NI observed was burn-wound infection (58.3%), followed by bacteraemia-sepsis (16.7%). NIs were not detected in the rest at all (Group B). The mean length of hospitalization was 38.5+/-19.7 days in Group A, and 20.3+/-7.6 days in Group B. The mean total burned surface area (TBSA) was 43+/-21 in Group A and 29+/-18 in Group B, while the most important independent risk factor for NI was TBSA in burned patients (OR, 1.08; CI(95), 0.93-1.24). NI prolonged the mean hospital stay to 18 days and increased the cost of treatment by 502 US dollars. The most common bacteria isolated was Pseudomonas aeruginosa (41.7%) and the second was methicillin resistant Staphylococcus aureus (MRSA-25.0%). All of the NI-free patients survived, while, five (28.5%) patients with NI died (P<0.01). These findings emphasized the need for careful disinfection and conscientious contact control procedures in areas that serve immunosupressed individuals, such as burned patients.

Adverse events associated with methicillin-resistant Staphylococcus aureus in a nursing home

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) generates concern in nursing homes. Restrictive isolation precautions may be applied for indefinite periods. Adverse events driving these concerns include transmission and infection.

METHODS

The 721-bed Wisconsin Veterans Home in King performs approximately 645 cultures annually. The site, severity, and number of MRSA infections were determined for 69 months. Pulsed-field gel electrophoresis was performed on all initial isolates, followed by a statistical cluster analysis looking for evidence of transmission.

RESULTS

Sixty-seven MRSA infections were identified (1.6 per 100 residents per year); many were polymicrobial, and it was difficult to determine the proportionate role of MRSA in morbidity or mortality. There was an episode of rapidly fatal MRSA septicemia in which empiric antibiotic therapy was ineffective. Twenty-one genetic strains were encountered. Statistical analysis identified 13 clusters of genetically identical strains clustered in time and space (P<.05).

CONCLUSIONS

Infections with MRSA were identified at relatively low rates; however, the etiology of many serious nursing home infections is not determined, especially pneumonia. Statistical analysis revealed clustering and evidence of transmission. Nursing home practitioners should consider MRSA when applying empiric treatment to serious infections. We recommend a program including (1) judicious use of antibiotics, including topical agents, to reduce selection of resistant organisms; (2) obtaining and tracking cultures of infectious secretions to diagnose MRSA infections and focus antibiotic therapy; (3) universal standard secretion precautions because any resident could be a carrier; and (4) a detailed assessment and care plan for the carrier that maximizes containment of secretions and independence in activities. However, basic hygiene cannot be maintained in communal areas by some residents without restriction of activities of daily living.

[The chemoluminescence of the primary focus of a suppurative infection and of isolated neutrophils exposed to dimephosphon]

The influence of dimephosphone at concentrations of 0.001 M-0.75 M on the chemiluminescence of tissues at the focus of purulent infection in the ear of a guinea pig, on the survival rate of the experimental animals injected with the lethal dose of Staphylococcus aureus, as well as on the spontaneous and stimulated chemiluminescence of blood neutrophils in patients with wound infection, was studied. The study showed that different concentrations of dimephosphone oppositely influenced the intensity of the chemiluminescence of neutrophil suspensions and tissues at the focus of infection: low concentrations were found to produce stimulating action and high concentrations, suppressive action. At the highest concentration used in this study (0.75 M) dimephosphone prevented the death of the animals receiving lethal doses of S. aureus.