Toshikiyo Hayashi

Macrolide-resistant Mycoplasma pneumoniae in adolescents with community-acquired pneumonia

BackgroundAlthough the prevalence of macrolide-resistant Mycoplasma pneumoniae isolates in Japanese pediatric patients has increased rapidly, there have been no reports concerning macrolide-resistant M. pneumoniae infection in adolescents aged 16 to 19 years old. The purpose of this study was to clarify the prevalence and clinical characteristics of macrolide-resistant M. pneumoniae in adolescent patients with community-acquired pneumonia.MethodsA total of 99 cases with M. pneumoniae pneumonia confirmed by polymerase chain reaction (PCR) and culture were analyzed. Forty-five cases were pediatric patients less than 16 years old, 26 cases were 16 to 19-year-old adolescent patients and 28 cases were adult patients. Primers for domain V of 23S rRNA were used and DNA sequences of the PCR products were compared with the sequence of an M. pneumoniae reference strain.ResultsThirty of 45 pediatric patients (66%), 12 of 26 adolescent patients (46%) and seven of 28 adult patients (25%) with M. pneumoniae pneumonia were found to be infected with macrolide-resistant M. pneumoniae (MR patients). Although the prevalence of resistant strains was similar in pediatric patients between 2008 and 2011, an increase in the prevalence of resistant strains was observed in adolescent patients. Among 30 pediatric MR patients, 26 had an A-to-G transition at position 2063 (A2063G) and four had an A-to-G transition at position 2064 (A2064G). In 12 adolescent MR patients, 10 showed an A2063G transition and two showed an A2064G transition, and in seven adult MR patients, six showed an A2063G transition and one showed an A2064G transition.ConclusionsThe prevalence of macrolide-resistant M. pneumoniae is high among adolescent patients as well as pediatric patients less than 16-years old. To prevent outbreaks of M. pneumoniae infection, especially macrolide-resistant M. pneumoniae, in closed populations including among families, in schools and in university students, physicians should pay close attention to macrolide-resistant M. pneumoniae.

Influence of age on the clinical differentiation of atypical pneumonia in adults

Background and objective:  The Japanese Respiratory Society (JRS) scoring system is a useful tool for the early and simple presumptive diagnosis of atypical pneumonia (Mycoplasma pneumoniae and Chlamydia pneumoniae pneumonia). However, it has been suggested that it is difficult to diagnose atypical pneumonia in the elderly using this system. In the present study, we evaluated the accuracy and usefulness of the JRS scoring system for diagnosing atypical pneumonia in different age groups.

Clinical features of Proteus mirabilis pneumonia

In this study, we clinically reviewed 13 patients with Proteus mirabilis pneumonia who were admitted for treatment to Kawasaki Medical School Kawasaki Hospital, Okayama, Japan, between April 2006 and July 2009. Clinical features were retrospectively reviewed. Results showed that: (1) hospital-acquired pneumonia occurred in elderly patients with underlying diseases such as cerebrovascular disease; (2) some patients had complications of urinary tract infection due to P. mirabilis; (3) preadministration of antibacterial agents did not become a risk factor; (4) resistance for levofloxacin (LVFX) was observed; (5) prognosis was comparatively good (effective rate 84.7%).

Clinical features of Escherichia coli pneumonia

Escherichia coli pneumonia was clinically reviewed. Twenty-two patients with E. coli pneumonia were admitted for treatment to Kawasaki Medical School Kawasaki Hospital, between January 2006 and December 2008. Clinical features were retrospectively reviewed. Results showed that: (1) hospital-acquired pneumonia occurred in elderly patients with underlying diseases, such as cerebrovascular disease, diabetes mellitus, or chronic obstructive pulmonary disease; (2) more patients had complications of urinary-tract infection or alimentary infection due to E. coli; (3) previous administration of antibacterial agents did not become a risk factor; (4) resistance to ampicillin (ABPC) and levofloxacin (LVFX) was observed; and (5) mortality was 22.7%.

Clinical effect of biapenem on nursing and healthcare-associated pneumonia (NHCAP)

The clinical effect of Biapenem (BIPM) on Nursing and Healthcare-associated pneumonia (NHCAP) was evaluated. One hundred and three NHCAP patients (Group B: 52 patients, Group C: 51 patients) to whom BIPM was administered were included in this study. Clinical effect, bacteriological effect, and adverse events were examined. Results revealed efficacy in 45 of 52 patients (efficacy rate: 86.5%) of NHCAP Group B, and 43 of 51 patients (efficacy rate: 84.3%) of NHCAP Group C, 88 of 103 patients (efficacy rate: 85.4%) as a whole. As for bacteriological effect, 10 (76.9%) of 13 Pseudomonas aeruginosa strains, 9 (90.0%) of 10 Klebsiella pneumoniae strains, 7 (87.5%) of 8 methicillin-sensitive Staphlococcus aureus strains, and 7 (100%) of 7 Streptococcus pneumonia strains were eradicated. As a whole, 38 (80.9%) of 47 strains were eradicated. Adverse events included drug fever and drug eruption in one patient each, and abnormal laboratory findings, including mild hepatic dysfunction in 18 patients and mild renal dysfunction in 5 patients. Based on the above, it was concluded that BIPM shows excellent clinical effect on NHCAP with fewer adverse events.