No abstract

This study describes early intracellular events occurring during the establishment phase of Bacillus anthracis infections. Anthrax infections are initiated by dormant endospores gaining access to the mammalian host and becoming engulfed by regional macrophages (Mφ). During systemic anthrax, late stage events include vegetative growth in the blood to very high titres and the synthesis of the anthrax exotoxin complex, which causes disease symptoms and death. Experiments focus on the early events occurring during the first few hours of the B. anthracis infectious cycle, from endospore germination up to and including release of the vegetative cell from phagocytes. We found that newly vegetative bacilli escape from the phagocytic vesicles of cultured Mφ and replicate within the cytoplasm of these cells. Release from the Mφ occurs 4–6 h after endospore phagocytosis, timing that correlates with anthrax infection of test animals. Genetic analysis from this study indicates that the toxin plasmid pXO1 is required for release from the Mφ, whereas the capsule plasmid pXO2 is not. The transactivator atxA, located on pXO1, is also found to be essential for release, but the toxin genes themselves are not required. This suggests that Mφ release of anthrax bacilli is atxA regulated. The putative ‘escape’ genes may be located on the chromosome and/or on pXO1.

An anaerobic 2,4,6-tribromophenol debrominating bacterium, strain DSL-1, was isolated from enrichment cultures inoculated with sediment from the burrows of the bromoaromatic-producing marine hemichordates Balanoglossus aurantiacus and Saccoglossus kowalewskyi. DSL-1 preferentially removed ortho-position bromines, resulting in the transient appearance of 2,4-dibromophenol and accumulation of 4-bromophenol. Cell-free extracts and partially purified reductive debrominase preparations from DSL-1 also debrominated 2,4,6-tribromophenol, yielding 2,4-dibromophenol and 4-bromophenol. Both NADH and NADPH stimulated 2,4,6-tribromophenol reduction by partially purified debrominase. These data are consistent with a reductive debromination mechanism. The organic cosubstrate(s) and specific electron donors used by DSL-1 in vivo are currently unknown.Key words: dehalogenation, bromometabolites, bromophenols, hemichordates.

There are currently 12 species and over 100 serotypes that have been identified in the enterovirus genus, including the coxsackieviruses, echoviruses, and polioviruses. Since their discovery 65 years ago, much has been discovered and continues to be researched regarding the pathogenicity and scope of disease of nonpolio enteroviruses. Like many infections, enteroviruses have been found to affect neonates much differently, and often more severely, than older children and adults. Neonatal infections often cause mild illnesses with nonspecific symptoms, but they may also have severe presentations involving the cardiovascular, gastrointestinal, hematologic, or central nervous systems. This article provides an overview of what is known about nonpolio enteroviruses in neonates including epidemiology, transmission, clinical presentation, diagnosis, and treatment.

Botulism developed in a patient following surgical repair of an open radial fracture. Symptoms resolved after treatment with antitoxin and antibiotics, and hardware excision was deferred. Subsequent osteomyelitis necessitated hardware exchange, and wound cultures grew Clostridium argentinense. This case highlights the management of botulism associated with orthopedic hardware. CASE REPORTA 34-year-old man without significant past medical history presented with double vision. Three weeks prior to admission he suffered a compound fracture of his right radius and ulna during a soccer game. He was admitted to the orthopedic service for open reduction and internal fixation with a midulnar and radial plate (see Fig. 1). During the procedure, grass and dirt were noted in the surgical bed. He was treated perioperatively with cefazolin and gentamicin, was discharged, and completed 10 days of cephalexin treatment. Eighteen days following surgical repair he noted both double vision and difficulty opening both eyes. He presented three days later after worsening of symptoms and the development of slurred speech and difficulty swallowing.On admission, he denied fevers or chills, wound breakdown, paresthesias, or any other symptoms and asserted adherence to his postoperative antibiotics. The patient had no significant past medical history, took no other medications, and denied recreational drug use. His speech was dysphonic, and he had bilateral ptosis with notable diplopia. There was severe upper and lower bifacial weakness, and only trace extraocular movement was seen. His pupils were large and minimally reactive to light or accommodation. There was notable tongue and pharyngeal weakness. His right arm showed a healing surgical wound on the volar surface of his forearm. The results of the rest of his examination were unremarkable, as were his laboratory results.A nerve conduction study and electromyogram procedure were conducted, and the interpretation documented "low baseline amplitudes, especially in proximal musculature, with significant facilitation"; the interpreting neurologist noted that in the appropriate clinical context, the features were consistent with wound botulism. The patient was promptly administered a dose of botulinum antitoxin obtained from the CDC (7,500 units of antitoxin A and 5,500 units of antitoxin type B in 100 ml of normal saline solution over 1 h). Infectious disease consultants recommended commencing high-dosage intravenous penicillin G treatment and planning for surgical debridement and removal of the implanted hardware. After receiving botulinum antitoxin, his clinical symptoms improved overnight, and surgical excision was deferred. A blood sample obtained prior to the administration of botulinum antitoxin was negative for Clostridium botulinum toxin when tested by the CDC after trypsinization by use of a mouse bioassay. His symptoms improved, and he was discharged to complete 6 weeks of oral metronidazole and clindamycin treatment.Radiographs obtained 6 weeks after discharge were indicative o...

While combination antiretroviral therapy allows HIV-infected patients to have life expectancies similar to that of the general population, it may also contribute to the development of co-morbidities, such as cardiovascular disease and osteoporosis. Such complications could compromise long-term quality of life, especially in HIV-infected youth whose lifetime cumulative exposure to antiretrovirals is likely to be many decades. Recent studies continue to demonstrate abnormalities associated with antiretroviral therapy, although clinical manifestations are rare in this younger population, especially with modern antiretrovirals. The purpose of this paper is to review the most recent literature on complications of treatment in youth with HIV.

Paenibacillus infections can be life threatening and are being reported with increasing incidence. There are only a few case reports of infections and are mainly described in patients who are immunocompromised, injection drug users, or those with prosthetic devices. Due to improved testing and identification, it appears that these infections may not be as rare as once perceived. We present a case of a 16-day-old term neonate who presented with status epilepticus and was found to have Paenibacillus thiaminolyticus meningoencephalitis. The patient was successfully treated with a combination of ampicillin and ceftazidime then meropenem. To our knowledge, this is the first reported case of an infant in the United States who survived this serious invasive infection. We also present an option for therapy given the difficulty treating invasive intracranial infections.

Chronic mucocutaneous candidiasis is a heterogeneous group of immunodeficiencies associated with persistent candidal infections. Patients with chronic mucocutaneous candidiasis are rarely associated with systemic infections caused by other fungi, but almost never by Candida. The authors report a case of a 16-year-old with chronic mucocutaneous candidiasis who developed a fungemia with Candida tropicalis.