Seasonal trend and clinical presentation of Bacillus cereus bloodstream infection: association with summer and indwelling catheter.

Bacillus cereus, an opportunistic pathogen, can cause fatal infection. However, B. cereus bloodstream infections (BSIs) have not been well characterised. From 2008 to 2013, B. cereus isolates from all of the specimens and patients with B. cereus BSIs were identified. Environmental samples were collected to detect B. cereus contamination. We also characterised the clinical presentation of B. cereus BSI through analyses of risk factors for BSI and mortality. A total of 217 clinical B. cereus isolates was detected. Fifty-one patients with nosocomial infections were diagnosed as B. cereus BSI, and 37 had contaminated blood cultures. The number of B. cereus isolates and BSI patients was significantly greater from June to September than from January to April (4.9 vs. 1.5 per month and 1.2 vs. 0.2, respectively). All BSIs were nosocomial and related to central or peripheral vascular catheter. Urinary catheter [odds ratio (OR) 6.93, 95% confidence interval (CI) 2.40-20.0] was the independent risk factor associated with BSI patients when compared to patients regarded as contaminated. In-hospital mortality among BSI patients was 20% and was associated with urinary catheter (OR 34.7, 95 % CI 1.89-63.6) and higher Charlson index (OR 1.99, 95 % CI 1.26-3.12). The number of B. cereus isolates and BSI increased during summer. Inpatients with indwelling vascular or urinary catheters should be carefully monitored for potential B. cereus BSIs.

Bacillus sphaericus bacteraemia in children with cancer: case reports and literature review.

In the period 1989-1999, Bacillus sphaericus was demonstrated to cause 12 out of 469 (2%) episodes of bacteraemia in children with cancer or receiving bone marrow transplant at G. Gaslini Children's Hospital, Genoa, Italy. Neutropenia was present in five episodes, six episodes, (all without neutropenia) were related to the presence of a central venous catheter, and one episode occurred in a patient with intestinal graft vs. host disease and gut colonization. All patients survived. Ciprofloxacin was the only drug active against all the isolated strains.Bacillus sphaericus represents a new cause of infection in the immunocompromised host, with low aggressiveness, but a peculiar pattern of antibiotic susceptibility.

Super-infection by Bacillus thuringiensis H34 or 3a3b can lead to death in mice infected with the influenza A virus.

Bacterial super-infections are the main cause of complication and mortality after influenza virus (IAV) infection. Since Bacillus thuringiensis (Bt) is considered non-pathogenic for humans and is widely sprayed in urban areas, the aim of this work was to evaluate the potential pathogenicity of a combined infection Bt-IAV in a mouse model of pneumonia. Bacteria used for super-infections were Bt serotype H34 isolated from human infection and the insecticidal strain 3a3b obtained from a commercial source. Virus strain was A/Scotland/20/74 (H3N2) adapted to BALB/c mice by serial lung passage. Combined infection with 4% of the viral lethal dose 50% (LD(50)) and 10(2) spores of Bt H34 killed 40% of the mice. Mortality rates increased up to 55% and 100% when combined infections were done with respectively 10(4) and 10(7) spores. The insecticidal strain Bt 3a3b was less pathogenic than Bt H34. A dose of 10(4) spores associated with 4% of IAV LD(50) killed 50% of the mice. This inoculum must be compared with the doses usually sprayed in agriculture: 10(11) spores m(-2). Total protection against super-infection was obtained when mice were treated with amantadine. Even if only a few cases of Bt human infection have been reported, these results suggest a possible risk for workers spraying Bt-based biopesticides during flu outbreaks.

[The effect of heterologous bacilli on the infectious process in anthrax in an experiment]. / Vliianie geterologicheskikh batsill na infektsionnyi protsess pri sibirskoi iazve v éksperimente.

The possibility of the survival of guinea pigs after the simultaneous administration of different doses of Bacillus anthracis virulent strain 81/1 in combination with both B. anthracis vaccine strain STI and heterologous bacilli (B. subtilis strain PAC) has been experimentally shown. On the basis of the results of these experiments suggestion has been made that the "survival phenomenon" is the process involving the lysosomal systems of polymorphonuclear and mononuclear phagocytes.