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An increasing incidence of carbapenem-resistant Klebsiella pneumoniae(CRKP) infections has been reported worldwide. The aim of this study was to investigate the mechanism underlying carbapenem resistance and its relationship to antibiotic exposure. Sixteen isolates with various carbapenem susceptibilities recovered from five patients between 2003 and 2006 were subjected to molecular study. The medical records of the patients were also reviewed. All of the patients were admitted for complicated respiratory illness, had a prolonged hospital stay, and were exposed to antibiotics. Carbapenems were prescribed before the emergence of the CRKP. Various combinations of extended-spectrum cephalosporinase genes belonging to the SHV, CTX-M, and AmpC groups were found among the isolates. Other carbapenem resistance-associated genes, such as blaIMP, blaVIM, blaOXA, and blaKPC, were not found. OmpK35 was not expressed in any of the isolates, and additional loss of OmpK36 was observed in all CRKP isolates. Two insertion elements, ISPa13or IS5, were found inserted into OmpK36 in the isolates derived from three patients. These IS elements were also identified in their parental carbapenem-susceptible isolates, suggesting that an internal transposition into OmpK36 resulted in resistance. OmpK36 loss represents the major mechanism for the development of CRKP in extended-spectrum cephalosporinase-producing isolates. A prolonged hospital stay and recent carbapenem exposure may predispose patients to CRKP, impacting the clinical outcome. [ABSTRACT FROM AUTHOR]

Introduction: Mycobacterium marinum causes skin and soft tissue, bone and joint, and rare disseminated infections. In this study, we aimed to investigate the relationship between treatment outcome and antimicrobial susceptibility patterns. A total of 27 patients with M. marinum infections were enrolled. Methods: Data on clinical characteristics and therapeutic methods were collected and analyzed. We also determined the minimum inhibitory concentrations of 7 antibiotics against 30 isolates from these patients. Results: Twenty-seven patients received antimycobacterial agents with or without surgical debridement. Eighteen patients were cured, 8 failed to respond to treatment, and one was lost to follow-up. The duration of clarithromycin (147 vs. 28; p = 0.0297), and rifampicin (201 vs. 91; p = 0.0266) treatment in the cured patients was longer than that in the others. Surgical debridement was performed in 10 out of the 18 cured patients, and in 1 of another group (p = 0.0417). All the 30 isolates were susceptible to clarithromycin, amikacin, and linezolid; 29 (96.7%) were susceptible to ethambutol; 28 (93.3%) were susceptible to sulfamethoxazole; and 26 (86.7%) were susceptible to rifampicin. However, only 1 (3.3%) isolate was susceptible to doxycycline. Discussion: Early diagnosis of the infection and appropriate antimicrobial therapy with surgical debridement are the mainstays of successful treatment. Clarithromycin and rifampin are supposed to be more effective agents. [ABSTRACT FROM AUTHOR]

Objectives: Mycobacterium kansasii causes a variety of infections. Although previous reports on the prognosis of antimicrobial therapy have been mostly satisfactory, problems involving treatment failure or relapse have been encountered. The purpose of this study was to establish a relationship between the clinical treatment outcomes of M. kansasii infections and bacterial drug susceptibility, and their clonality. [ABSTRACT FROM PUBLISHER]

Abstract Objectives  The aim of this study was to evaluate immunity in HIV-uninfected children with bacille Calmette–Guerin-induced disease (BCG-ID) over an 8-year period, with particular emphasis on underlying diseases. Methods  Patient afflicted with BCG-ID proven by clinical courses, dermatologic features, pathology, specific polymerase chain reaction, and/or spoligotyping were enrolled between 2000 and 2007. Lymphocyte proliferation, polymorphonuclear function, interleukin (IL)-12/23–interferons (IFN)-γ circuit, and Toll-like receptor 2-associated signaling were investigated. Results  Of the 271,618 total live births who received the BCG vaccine, eight patients (seven males) with BCG-ID were enrolled during an 8-year period and presented as three disseminated, two distant, and three regional BCG-ID. Their age at onset ranged from 1 to 28 months. All had a vaccine-injection scar except for one with lower CD3 and natural killer cells, compatible with severe combined immunodeficiency (SCID) identified by IL-2 receptor common gamma chain (IL2RG) mutation (Arg226Lys). The other SCID patient with de novo IL2RG mutation (Trp74Gly) had more recurrent infections. The third patient with primary autoimmune neutropenia had disseminated BCG-ID extending to abdominal wall. The fourth patient with chronic mucocutaneous candidiasis had regional BCG-ID and impaired lymphocyte proliferation to Candida and BCG antigens. No defective evidence of polymorphonuclear functions, IL-12/23–IFN-γ circuit, and Toll-like receptor 2-associated signaling was detected in the remaining four patients. Conclusion  Immunologic analysis in HIV-uninfected patients with BCG-ID reveals primary immunodeficiency diseases, especially in those with deficiencies in T-cell and neutrophil functions observed in our cohort, including primary autoimmune neutropenia and chronic mucocutaneous candidiasis. [ABSTRACT FROM AUTHOR]

Streptococcus mitis (a common and usually harmless bacterium found in the nose, mouth and throat) can have an unusually high level of resistance to β-lactam antibiotics. We report a patient who developed fatal Streptococcus mitis septicaemia following unrelated cord blood transplantation. Administration of vancomycin to patients with recurrent fever during allogeneic stem cell transplantation might be indicated. [ABSTRACT FROM AUTHOR]