A prospective study of intrafamilial transmission and antimicrobial susceptibility of Moraxella catarrhalis.

Moraxella catarrhalis has been recognized as a particularly threatening respiratory tract pathogen in humans. A prospective study was performed to investigate which strains of M. catarrhalis can be transmitted within families; the study also addressed features of antimicrobial susceptibility. Seventy-five strains were isolated from six participants between July 2002 and February 2004, including 73 that were verified as beta-lactamase-producing strains. Antimicrobial susceptibility was tested for six types of antibiotics and no treatment issues were found. Pulsed-field gel electrophoresis (PFGE) was performed on all strains and 25 independent PFGE patterns were detected. The dominant pattern L (defined in the present study) was found in 21 (28%) of strains that were continuously recovered from children from the same family over an 8-month period. Strains with the patterns G, J, L, M, R, S, U, and W seemed to spread among the children, but there was no evidence of child-parent transmission. In the present study, the characteristics of M. catarrhalis within families have been documented, and PFGE profiles found to reveal alternating colonization and intrafamilial transmission.

[Three adult cases with Corynebacterium propinquum respiratory infections in a community hospital].

Corynebacterium propinquum, which is included in Corynebacterium group ANF-3, exists as a commensal in the oral flora. This organism has not yet been fully recognized as a respiratory pathogen. We previously reported that the first case with respiratory infection caused by C. propinquum. On the other hand, Corynebacterium pseudodiphtheriticum is recognized as a causative organism in respiratory infections. Recently we experienced two cases with C. propinquum respiratory infections in our hospital. Three types of the onset such as a community-acquired infection, a hospital-acquired infection, and a nursing home acquired infections were observed. Our analysis indicated that gram staining of the purulent sputum is an essential tool to evaluate whether C. propinquum is a respiratory pathogen or not, because this organism is a commensal bacteria.

[A retrospective analysis of community-acquired pneumonia between 2000 and 2002 in a community hospital].

We previously reported a hospital-based retrospective study on community-acquired pneumonia (CAP) at Tagami Hospital, which was a community hospital, between 1994 and 1997. This study was designed to clarify the etiology of CAP diagnosed between 2000 and 2002. We analyzed a total of 124 cases of CAP in our hospital during the study period, and compared the results with the previous data. Identification of the causative organisms of CAP was based on gram staining, the morphology of the colonies, quantitative culture of the sputum, and the serological tests. During the study period, we determined the causative organisms in 42 cases (33.8%). Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were the major causative organisms. The severity of the cases was classified into three groups according to the guideline for CAP, which was edited by the Japanese Respiratory Society. The survival rates in the moderate and severe groups were significantly (p < 0.001) higher than that of the mild group, as analyzed by the Kaplan-Meier method, as follows: 70% (moderate) vs 100% (mild); and 40% (severe) vs 100% (mild). In a total of 7 patients who died, we found the following risk factors: elderly male patients, bedridden status with cerebral infarction, and micro-aspiration, including recurrent pneumonia at short intervals of less than 17 days. Our study indicated that the JRS-edited guideline for CAP is a very useful tool for analyzing cases with CAP in Japan.

Usefulness of the Japanese Respiratory Society guidelines for community pneumonia: a retrospective analysis of community-acquired pneumonia between 2000 and 2002 in a general hospital.

OBJECTIVE: The aim of this study was to investigate the causative organisms of community-acquired pneumonia (CAP) diagnosed between 2000 and 2002 and to evaluate the Japanese Respiratory Society (JRS) guidelines. METHODOLOGY: A total of 124 cases of CAP diagnosed during the study period were analyzed, and the results were compared with those of a previous study by the authors' research group. Determination of the causative organisms of CAP was based on Gram stain, morphology of colonies, quantitative culture of sputum, identification of bacterial isolates, and serological tests. RESULTS: During the study period, the causative organisms were identified in 42 cases (33.8%). Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were the major causative organisms. Patients were classified into three groups based on the severity of CAP according to the JRS guidelines. The survival rates of patients with moderate and severe CAP were significantly lower than those of the mild group as evaluated by the Kaplan-Meier method (moderate vs mild, 70% vs 100%; severe vs mild, 40% vs 100%; P < 0.001 for both). Seven patients died during the study, and the risk factors were old age, bedridden status with cerebral infarction, and microaspiration, which was associated with recurrent pneumonia within 17 days. CONCLUSION: This study indicates that the JRS guidelines for CAP are useful for treating patients with CAP in Japan.

Possible relationship of PFGE patterns of Moraxella catarrhalis between hospital- and community-acquired respiratory infections in a community hospital.

We describe a prospective study of molecular analysis of Moraxella catarrhalis isolated from a community hospital. Our study was designed to investigate the possible relationship of pulsed-field gel electrophoresis (PFGE) patterns of M. catarrhalis between hospital- and community-acquired respiratory infections. A nosocomial outbreak of M. catarrhalis was observed between September 2000 and September 2001. During the study period, 40 strains of M. catarrhalis were isolated from a total of 32 patients with respiratory infections (26 strains from 18 inpatients, and 14 strains from 14 outpatients). We compared the PFGE patterns in 40 strains of M. catarrhalis isolated from the respiratory tract of the study patients. The genomic types of M. catarrhalis were classified into three PFGE patterns (A, B, and C). Interestingly, the nosocomial outbreak of M. catarrhalis included two patterns (A and B). Of the three patterns, two patterns (A and B) were found in both inpatients and outpatients. More interestingly, two subtypes of pattern B (B1 and B4) were simultaneously found in both inpatients and outpatients. Our results indicated that PFGE with SmaI chromosomal digestion is a suitable technique to establish the inter-strain genetic relatedness of M. catarrhalis, and suggested that the outbreak of M. catarrhalis occasionally included miscellaneous PFGE patterns. The results also showed that PFGE patterns of M. catarrhalis isolates were similar between hospital- and community-acquired respiratory infections. Analysis of the subtypes suggested that there might be some association between hospital- and community-acquired respiratory infections caused by M. catarrhalis.