The Impact of a Change in Antibacterial Prophylaxis from Ceftazidime to Levofloxacin in Allogeneic Hematopoietic Cell Transplantation

Antibiotic prophylaxis has been used during the initial phases of myeloablative hematopoietic cell transplantation (HCT) for more than two decades. However, the optimal regimen in terms of both cost and clinical effectiveness is unclear. We retrospectively compared the clinical and microbiological impact of a change in antibiotic prophylaxis practice from ceftazidime (n=216 patients with HCT in 2000–2002) to levofloxacin (n=219 patients, August 2002–2005) in patients receiving myeloablative conditioning. Levofloxacin prophylaxis was associated with fever and a change in antibiotics during neutropenia, but this strategy was not associated with any adverse outcomes. Patients receiving levofloxacin had lower rates of significant bacteremia than did those receiving ceftazidime (day 100, 19.2 vs 29.6%, P=0.02). The use of levofloxacin was associated with lower antibiotic acquisition costs. There was no deleterious impact caused by levofloxacin prophylaxis on survival, emergence of antibiotic resistance, detection of Clostridium difficile Ag in stool specimens, incidence of viridans group streptococcal bacteremia or Pseudomonas infections. There was a trend toward lower rates of bacteriuria, wound and bacterial respiratory infections in the levofloxacin than in the ceftazidime group, but these differences were not statistically significant. These data support the use of levofloxacin as prophylaxis in myeloablative allogeneic HCT when prophylaxis is used

Surto de listeriose sistêmica em chinchilas Outbreak of systemic listeriosis in chinchillas

A listeriose é uma doença infecciosa que afeta uma grande variedade de espécies animais, causando septicemia, encefalite e aborto. As chinchilas são os animais mais susceptíveis à infecção sistêmica por Listeria monocytogenes. Este relato descreve um surto de listeriose sistêmica em uma criação de chinchilas da região central do Estado do Rio Grande do Sul, onde cerca de 16% das chinchilas morreram. Na necropsia, havia múltiplos focos brancos, pequenos e de distribuição aleatória nas superfícies capsular e de corte do fígado e aumento de volume do linfonodo hepático. Histologicamente, observaram-se hepatite necrossupurativa e linfadenite supurativa multifocais, com numerosos bacilos intralesionais. L. monocytogenes foi o agente etiológico do surto de listeriose sistêmica, sendo o diagnóstico confirmado por meio das lesões de necropsia e histopatológicas, das características fenotípicas e genotípicas da bactéria e da técnica de imuno-histoquímica.<br>Listeriosis is an infectious disease, which affects a variety of animal species and cause septicemia, encephalitis and abortion. Chinchillas are the most susceptible animals to the systemic infection by Listeria monocytogenes. This report describes an outbreak of systemic listeriosis in a farm of chinchillas in the Central region of the Rio Grande do Sul state, Brazil. Mortality rate was about 16%. On necropsy, there were multiple random small white foci on the liver capsule and parenchyma and enlargement of the hepatic lymph node. Histologically, there were multifocal necro-suppurative hepatitis and suppurative lymphadenitis with numerous intralesional bacilli. L. monocytogenes was the etiology of the systemic listeriosis outbreak. The diagnosis was based on gross and microscopic lesions, genotypical and phenotypical characteristics and by immunohistochemistry technique

Chlamydia pneumoniae in vitro and in vivo: a critical evaluation of in situ detection methods

Aims—There is a considerable discrepancy between data from the detection of Chlamydia pneumoniae in atherosclerotic lesions obtained by means of immunocytochemistry and data obtained using the polymerase chain reaction. This study evaluated methods for the in situ detection and assessment of the viability of C pneumoniae bacteria. Methods—Chlamydia pneumoniae membrane protein, heat shock protein 60, and lipopolysaccharide were detected by immunocytochemistry, and genomic DNA and 16S rRNA by in situ hybridisation in paraffin wax embedded sections of cultured HEp2 cells infected with C pneumoniae and of lungs from mice infected intranasally with C pneumoniae. Results—Inclusions reactive for all three antigens, DNA, and 16S rRNA were seen in infected HEp2 cells, in all positive bronchus and alveolar epithelial cells, and in some of the positive infiltrate cells in the lungs of mice up to seven days after infection. In all alveolar macrophages and in the infiltrate cells positive for antigens only, the staining pattern was granularly dispersed throughout the cytoplasm up to seven days after infection. At 21 days after infection, only this granular staining pattern was seen for antigens in infiltrate cells and macrophages in the alveoli and bronchus associated lymphoid tissue. At this time point, DNA or 16S rRNA were detected sporadically, but always as inclusion-like staining. Conclusions—Because antigens with an inclusion-like staining were detected only together with DNA and 16S rRNA, this type of staining pattern suggested the presence of viable bacteria. Thus, the granular staining pattern of antigens in the absence of staining for DNA and 16S is most likely caused by non-viable bacteria. In conclusion, these methods are suitable for the in situ detection of C pneumoniae and the assessment of its viability. Key Words: Chlamydia pneumoniae • immunocytochemistry • in situ hybridisation • animal mode

Identificação diferencial de Rhodococcus equi e Dietzia maris em bubalinos Differential identification of Rhodococcus equi and Dietzia maris in buffaloes

Foram analisados 24 isolados bacterianos oriundos de leite e pele de búfalas (Bubalus bubalis), os quais foram previamente identificados como Rhodococcus equi com o auxílio de fenotipia concisa. Testes fenotípicos complementares e ferramentas moleculares foram utilizados com o objetivo de caracterizar esses isolados, bem como diferenciá-los de outros microrganismos intimamente relacionados. Observaram-se três fenótipos distintos, porém a identificação dos isolados foi inconclusiva. Apenas um dos isolados foi comprovado como sendo R. equi com a realização da PCR espécie-específica, sequenciamento e análise dos fragmentos de DNA. Os demais isolados só foram identificados pelo sequenciamento de fragmento do gene que codifica a região 16S do rRNA universal de bactérias, indicando tratar-se de Dietzia maris. O perfil de susceptibilidade aos antimicrobianos revelou maior resistência dos isolados de D. maris para oxacilina (96%) e rifampicina (87%). O isolado de R. equi apresentou resistência à amicacina, oxacilina, penicilina, rifampicina e tetraciclina. Alerta-se para o risco da incorreta identificação dos isolados baseados em testes fenotípicos concisos e para a necessidade de utilização de testes complementares para diferenciação entre R. equi e D. maris.<br>Twenty-four bacterial isolates from milk and skin of buffalo females (Bubalus bubalis), which previously had been identified as Rhodococcus equi by using a restricted number of phenotypical tests for bacterial characterization, were analyzed. The goal of this study was to perform the characterization of these isolates, as well as the differentiation of other microorganisms closely related by using additional phenotypical tests and molecular tools. Based on the phenotypical results, three different biotypes were obtained. However, the identification of the isolates was inconclusive. Only one of the isolates was confirmed as R. equi by the PCR specifically for this species, as well DNA sequencing and DNA fragment analysis. All the other isolates only could be precisely identified after the DNA sequencing, and they were characterized as Dietzia maris. The sensitivity profile to antimicrobials demonstrated the highest resistance of D. maris to oxacillin and rifampin, 96% and 87%, respectively. R. equi isolate, presented resistance to amikacin, oxacillin, penicillin, rifampin, and tetracycline. Thus, it is important to alert for the risk of the incorrect identification of the bacterial isolates by using diagnostic analysis based on phenotypical tests in order to differentiate R. equi and D. maris, besides the necessity to use complementary tests for differentiation of these microorganisms

Whipple's disease revisited

Whipple's disease has traditionally been considered to be a rare multisystem disorder dominated by malabsorption. The recent identification of the Whipple's disease bacillus has, using polymerase chain reaction based assays, fuelled advances in the investigation, diagnosis, and management of this disease. This leader reviews the aetiology, clinical manifestations, investigation, and treatment of Whipple's disease in the light of this new information. Key Words: Tropheryma whippelii • immune system • polymerase chain reactio