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To evaluate scoring systems to predict Legionella pneumonia and therapeutic efficacy against Legionella pneumonia, the Japanese Society of Chemotherapy Legionella committee has collected data on cases of Legionella pneumonia from throughout Japan. We analyzed 176 patients with Legionella pneumonia and compared them with 217 patients with Streptococcus pneumoniae pneumonia and 202 patients with Mycoplasma pneumoniae pneumonia. We evaluated four scoring systems, the Winthrop-University Hospital score, Community-Based Pneumonia Incidence Study Group score, and Japan Respiratory Society score, but they demonstrated limited sensitivity and specificity for predicting Legionella pneumonia. Using six clinical and laboratory parameters (high fever, high C-reactive protein, high lactate dehydrogenase, thrombocytopenia, hyponatremia, and unproductive cough) reported by Fiumefreddo and colleagues, only 6% had Legionnella pneumonia when less than 2 parameters were present. The efficacy rates of antibiotics at the time of termination were 94.6% for intravenous antibiotics, including ciprofloxacin and pazufloxacin, and 95.5% for oral antibiotics, including ciprofloxacin, levofloxacin, garenoxacin, moxifloxacin, and clarithromycin. Our results suggested that the previously reported clinical scoring systems to predict Legionnella pneumonia are not useful, but 6 simple diagnostic score accurately ruled out Legionnella pneumonia, which may help to optimize initial empiric therapy. Quinolones and clarithromycin still showed good clinical efficacy against Legionella pneumonia.

Legionella species are consistently identified as some of the most common causative agents of severe community-acquired pneumonia (CAP) or nosocomial pneumonia. Although the number of reported Legionella infection cases is gradually increasing in Japan, most cases are diagnosed by a urinary antigen test, which identifies only L. pneumophila serogroup 1. Therefore, assessment of pneumonia-causing Legionella species and serogroups would be important. The Japan Society for Chemotherapy Legionella committee has collected the isolates and clinical information on cases of sporadic community-acquired Legionella pneumonia throughout Japan. Between December 2006 and March 2019, totally 140 sporadic cases were identified, in which L. pneumophila was the most frequently isolated species (90.7%) followed by L. bozemanae (3.6%), L. dumofii (3.6%), L. micdadei (1.4%), and L. longbeachae (0.7%). Among 127 isolates of L. pneumophila, 111 isolates were of serogroup 1, two of serogroup 2, four of serogroup 3, one of serogroup 4, one of serogroup 5, seven of serogroup 6, and one was of serogroup 10. We also assessed in vitro activity of antibiotics against these isolates and showed that quinolones and macrolides have potent anti-Legionella activity. Our study showed that pneumonia-causing Legionella species and serogroup distribution was comparable to that reported in former surveillances. L. pneumophila was the most common etiologic agent in patients with community-acquired Legionella pneumonia, and L. pneumophila serogroup 1 was the predominant serogroup.

The activities of various antibiotics against 58 clinical isolates of Legionella species were evaluated using two methods, extracellular activity (minimum inhibitory concentration [MIC]) and intracellular activity. Susceptibility testing was performed using BSYEα agar. The minimum extracellular concentration inhibiting intracellular multiplication (MIEC) was determined using a human monocyte-derived cell line, THP-1. The most potent drugs in terms of MICs against clinical isolates were levofloxacin, garenoxacin, and rifampicin with MIC90 values of 0.015 μg/ml. The activities of ciprofloxacin, pazufloxacin, moxifloxacin, clarithromycin, and azithromycin were slightly higher than those of levofloxacin, garenoxacin, and rifampicin with an MIC90 of 0.03–0.06 μg/ml. Minocycline showed the highest activity, with an MIC90 of 1 μg/ml. No resistance against the antibiotics tested was detected. No difference was detected in the MIC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The MIECs of ciprofloxacin, pazufloxacin, levofloxacin, moxifloxacin, garenoxacin, clarithromycin, and azithromycin were almost the same as their MICs, with MIEC90 values of 0.015–0.06 μg/ml, although the MIEC of minocycline was relatively lower and that of rifampicin was higher than their respective MICs. No difference was detected in the MIEC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The ratios of MIEC:MIC for rifampicin (8) and pazufloxacin (2) were higher than those for levofloxacin (1), ciprofloxacin (1), moxifloxacin (1), garenoxacin (1), clarithromycin (1), and azithromycin (1). Our study showed that quinolones and macrolides had potent antimicrobial activity against both extracellular and intracellular Legionella species. The present data suggested the possible efficacy of these drugs in treatment of Legionella infections.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, was conducted by Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases and Japanese Society for Clinical Microbiology in 2010.The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period from January and April 2010 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical and Laboratory Standard Institutes using maximum 45 antibacterial agents.Susceptibility testing was evaluable with 954 strains (206 Staphylococcus aureus, 189 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 182 Haemophilus influenzae, 74 Moraxella catarrhalis, 139 Klebsiella pneumoniae and 160 Pseudomonas aeruginosa). Ratio of methicillin-resistant S.aureus was as high as 50.5%, and those of penicillin-intermediate and -resistant S.pneumoniae were 1.1% and 0.0%, respectively. Among H.influenzae, 17.6% of them were found to be β-lactamase-non-producing ampicillin (ABPC)-intermediately resistant, 33.5% to be β-lactamase-non-producing ABPC-resistant and 11.0% to be β-lactamase-producing ABPC-resistant strains. Extended spectrum β-lactamase-producing K.pneumoniae and multi-drug resistant P.aeruginosa with metallo β-lactamase were 2.9% and 0.6%, respectively.Continuous national surveillance of antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis., Journal of Infection and Chemotherapy, 21(6), pp.410-420; 2015

Akira Watanabe , Katsunori Yanagihara a, b, , Tetsuya Matsumoto , Shigeru Kohno a, , Nobuki Aoki a, , Toyoko Oguri , Junko Sato , Tetsuro Muratani , Morimasa Yagisawa , Kazuhiko Ogasawara , Naoto Koashi , Tsuneo Kozuki , Akira Komoto , Yoshisaburo Takahashi , Toshikatsu Tsuji , Michinori Terada , Kunio Nakanishi , Rikizo Hattori , Yukio Hirako , Akinori Maruo , Shinichi Minamitani , Kohei Morita , Tomotaro Wakamura , Keisuke Sunakawa , Hideaki Hanaki , Yoshinobu Ohsaki , Yasuhito Honda , Shoichi Sasaoka , Hiroaki Takeda , Hideki Ikeda , Atsuko Sugai , Makoto Miki , Susumu Nakanowatari , Hiroshi Takahashi , Mutsuko Utagawa , Nobuyuki Kobayashi , Jin Takasaki , Hisami Konosaki , Yasuko Aoki , Michi Shoji , Hajime Goto , Takeshi Saraya , Daisuke Kurai , Mitsuhiro Okazaki , Yoshio Kobayashi , Yasuhiro Katono , Akihiko Kawana , Katsu Saionji , Naoki Miyazawa , Yoshimi Sato , Yuji Watanuki , Makoto Kudo , Shigeru Ehara , Hiroki Tsukada , Yumiko Imai , Nobuei Watabe , Sakura Aso , Yasuo Honma , Hiroshige Mikamo , Yuka Yamagishi , Yoshio Takesue , Yasunao Wada , Tadahiro Nakamura , Noriko Mitsuno , Keiichi Mikasa , Kei Kasahara , Kenji Uno , Reiko Sano , Naoyuki Miyashita , Yukinori Kurokawa , Mariko Takaya , Masao Kuwabara , Yaeko Watanabe , Masao Doi , Satomi Shimizu , Kiyoshi Negayama , Junichi Kadota a, , Kazufumi Hiramatsu , Yoshitomo Morinaga , Junichi Honda , Masaki Fujita , Satoshi Iwata , Aikichi Iwamoto , Takayuki Ezaki , Shoichi Onodera , Shinya Kusachi , Kazuhiro Tateda , Michio Tanaka , Kyoichi Totsuka , Yoshihito Niki , Tetsuro Matsumoto a

For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 987 strains (189 Staphylococcus aureus, 211 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 187 Haemophilus influenzae, 106 Moraxella catarrhalis, 126 Klebsiella pneumoniae, and 162 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 β-lactams (four penicillins, three penicillins in combination with β-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), three aminoglycosides, four macrolides (including a ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standard Institute (CLSI). The incidence of methicillin-resistant S. aureus (MRSA) was as high as 59.8%, and those of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) were 35.5 and 11.8%, respectively. Among H. influenzae, 13.9% of them were found to be β-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 26.7% to be β-lactamase-non-producing ABPC-resistant (BLNAR), and 5.3% to be β-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5%) of β-lactamase-producing strains was suspected in Moraxella catarrhalis isolates. Four (3.2%) extended-spectrum β-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5%) of P.aeruginosa were found to be metallo β-lactamase-producing strains, including three (1.9%) suspected multidrug-resistant strains showing resistance to imipenem, amikacin, and ciprofloxacin. Continual national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.

This study was conducted by the Japanese Society of Chemotherapy and is the first nationwide study on bacterial pathogens isolated from patients with urinary tract infections at 28 hospitals throughout Japan between January 2008 and June 2008. A total of 688 bacterial strains were isolated from adult patients with urinary tract infections. The strains investigated in this study are as follows: Enterococcus faecalis (n = 140), Escherichia coli (n = 255), Klebsiella pneumoniae (n = 93), Proteus mirabilis (n = 42), Serratia marcescens (n = 44), and Pseudomonas aeruginosa (n = 114). The minimum inhibitory concentrations of 39 antibacterial agents used for these strains were determined according to the Clinical and Laboratory Standards Institute (CLSI) manual. All Enterococcus faecalis strains were susceptible to ampicillin and vancomycin. Although a majority of the E. faecalis strains were susceptible to linezolid, 11 strains (7.8%) were found to be intermediately resistant. The proportions of fluoroquinolone-resistant Enterococcus faecalis, Escherichia coli, Proteus mirabilis, and S. marcescens strains were 35.7%, 29.3%, 18.3%, and 15.2%, respectively. The proportions of E. coli, P. mirabilis, K. pneumoniae, and S. marcescens strains producing extended-spectrum β-lactamase were 5.1%, 11.9%, 0%, and 0%, respectively. The proportions of Pseudomonas aeruginosa strains resistant to carbapenems, aminoglycosides, and fluoroquinolones were 9.2%, 4.4%, and 34.8%, respectively, and among them, 2 strains (1.8%) were found to be multidrug resistant. These data present important information for the proper treatment of urinary tract infections and will serve as a useful reference for periodic surveillance studies in the future.