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The trends and prevalence of antimicrobial susceptibility of pathogens vary by country, region, and time. Long-term regular surveillance is required to investigate trends in the antimicrobial resistance of various isolated bacterial pathogens. We report the results of a nationwide surveillance on the antimicrobial susceptibility of bacterial respiratory pathogens in Japan conducted by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology. The isolates were collected from clinical specimens obtained from adult patients who visited a collaborating medical facility between June 2019 and December 2020 and were diagnosed with respiratory tract infections by a physician. Antimicrobial susceptibility testing was performed in a centralized laboratory according to the methods recommended by the Clinical and Laboratory Standards Institute. Susceptibility testing was performed for 932 strains (201 Staphylococcus aureus , 158 Streptococcus pneumoniae , 6 S. pyogenes , 136 Haemophilus influenzae , 127 Moraxella catarrhalis , 141 Klebsiella pneumoniae , and 163 Pseudomonas aeruginosa) collected from 32 facilities in Japan. The proportions of methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae were 35.3% and 0%, respectively. In H. influenzae , 16.2% and 16.9% were β-lactamase-producing ampicillin resistant and β-lactamase-negative ampicillin resistant, respectively. Extended-spectrum β-lactamase-producing K. pneumoniae accounted for 5.0% of all K. pneumoniae infections. Carbapenemase-producing K. pneumoniae and multi-drug-resistant P. aeruginosa with metallo-β-lactamase were not detected in this study. This surveillance will be a useful reference for treating respiratory infections in Japan and will provide evidence to enhance the appropriate use of antimicrobial agents. [ABSTRACT FROM AUTHOR]

Aims: Given the significance of Salmonella enterica in both human and animal health, and a recent global dissemination of Salmonella 4,[5],12:i:‐, changes in the prevalent serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs were investigated in Japan. Methods and Results: The serovars and antimicrobial susceptibilities of 1605 Salmonella enterica isolated from cattle (n = 894) and swine (n = 711) between 2002 and 2016 were examined. The most common serovar among all samples was Salmonella Typhimurium. However, its monophasic variant with antigenic structure S. 4,[5],12:i:‐, which was first detected in cattle in 2006 and swine in 2010, has been rapidly increasing in incidence and resistance. Resistance rates to cefotaxime and ciprofloxacin were generally low (<10% in the cattle isolates and <5% in the swine isolates); however, isolates resistant to more than five antimicrobials, which often include these antimicrobials, were recently detected in Salmonella Dublin, S. 4,[5],12:i:‐, S. Typhimurium, Salmonella Newport, Salmonella Choleraesuis and Salmonella 6,7:c:‐. Among them, two S. 4,[5],12:i:‐ isolates possessed extended‐spectrum β‐lactamase‐encoding genes; blaSHV‐12 or blaCTX‐M‐55, respectively, while all the five S. Typhimurium isolates possessed AmpC‐type β‐lactamase gene of blaCMY‐2. Conclusions: S. 4,[5],12:i:‐ has been rapidly increasing and exhibiting a remarkable change in antimicrobial resistance in Japan. Considering certain serovars are characterized by multidrug resistance including medically important antimicrobials, continuous monitoring and appropriate measures are required to protect public health and veterinary husbandry. Significance and Impact of the Study: This study presents a trend in the serovars and antimicrobial resistance in clinical isolates of Salmonella from cattle and pigs in Japan, and showed that there were certain types of Salmonella serovars depending on the animal origin which needs more attention. [ABSTRACT FROM AUTHOR]

Aspiration pneumonia is an infectious disease of the lungs caused by inhalation of saliva or foods, associated with swallowing dysfunction. Therefore, the major causative organisms are oral or gastric bacteria. In this study, we evaluated the antimicrobial susceptibility patterns of the anaerobic bacteria which can cause aspiration pneumonia, Fusobacterium spp., Finegoldia magna , Bacteroides fragilis , Peptostreptococcus spp., Prevotella spp., and Streptococcus milleri group to ceftriaxone, cefmetazole, flomoxef, ampicillin/sulbactam, and ampicillin. We also tested the β-lactamase activities of each of the bacterial strains. Fusobacterium spp. and Finegoldia magna were susceptible to all of the tested antimicrobial drugs, except ampicillin, and showed no β-lactamase activity. The Streptococcus milleri group, Bacteroides fragilis , and Peptostreptococcus spp. showed decreased susceptibility to cefmetazole or flomoxef as compared to the susceptibility levels documented in a previous report. There was one strain of Peptostreptococcus anaerobius which was not susceptible to ampicillin/sulbactam, but also showed no β-lactamase activity, suggesting that this strain harbored a mechanism of resistance other than the production of β-lactamase. The susceptibility of Prevotella spp. to ceftriaxone was also decreased as compared to the susceptibility level documented in a previous report. Furthermore, β-lactamase-positive strains were found even among ceftriaxone-susceptible strains. Elderly persons with swallowing dysfunction carry a risk of recurrent episodes of aspiration pneumonia and repeated use of antibiotics increases the risk of development of antibiotic resistance. In the present study, the antibiotic susceptibilities of some of organisms which can cause aspiration pneumonia were found to be decreased as compared to the susceptibility levels documented in a previous report. Therefore, surveillance of the antimicrobial susceptibility patterns of these bacteria is recommended to prevent the development of resistance. • The anaerobic bacteria can cause aspiration pneumonia. • We tested MICs of these bacteria which were isolated from 2008 to 2015 in Japan. • Susceptibilities of some strains are decreased compared with previous report. • The prevalence of beta-lactamase producing Prevotella spp. has increased. [ABSTRACT FROM AUTHOR]

The article discusses a study which characterized Salmonella enterica serovar Infantis (S. Infantis) isolates carrying cefotaxime (CTX)-M-14 extended-spectrum β-lactamase (ESBL) derived from broiler chickens raised at a poultry processing plant in western Japan in January 2010. It concludes that the spread of cephalosporin-resistant Salmonella spp. in poultry via the transmissible resistance plasmids elicits serious veterinary and public health concerns.

The New Delhi metallo-β-lactamase-1 (NDM-1) gene, bla, is an emerging plasmid-borne drug resistance gene, which encodes for exceptionally broad-spectrum β-lactamase, being able to hydrolyze a wide variety of β-lactams, including carbapenems, and was first reported in Klebsiella pneumoniae from a Swedish patient of Indian origin in 2009. It is widely distributed among Enterobacteriacae and has geographically exhibited extremely rapid and global spread. In this study, we characterized the bla-positive ST38 Escherichia coli strain NDM-1 Dok01 (which was isolated from the blood of a 54-year-old Japanese inpatient, who had previously visited India), focusing on bacterial surface structures related to virulence. The E. coli culture contained colony variants, which developed a transparent smooth colony and a rough colony on blood agar plates. The smooth colony-forming cells (substrain M1) possessed a surface capsule and were resistant to serum killing, whereas rough colony-forming mutants (substrain B2) lacked a capsule (and a 5.3-kb plasmid) and were highly susceptible to serum killing. Reflecting the surface structural difference, substrain M1 was more flagellated and motile, whereas substrain B2 was less flagellated and apparently possessed straight pili 5 nm wide, which played a role in adherence to human intestinal cells and bacterial autoaggregation. Data suggest that the bla-positive ST38 E. coli has emerged in Japan and that it is a capsulated bacterial pathogen with virulence potential in the blood stream. [ABSTRACT FROM AUTHOR]

In Japan, the increasing incidence of β-lactum-resistant Haemophilus influenzae infections is of growing concern. We retrospectively studied whether the prevalence of β-lactamase-negative ampicillin-resistant strains of H. influenzae was influenced by chronic lung diseases. H. influenzae isolates, obtained from patients who were diagnosed with acute or chronic bronchitis, or acute exacerbation of chronic bronchitis in 2005, were studied. In addition to susceptibility testing, polymerase chain reaction (PCR) was performed for the detection of TEM-1 β-lactamase, and Asn526-Lys and Ser385-Thr amino acid substitutions in the ftsI gene encoding penicillin-binding protein-3 (PBP-3). The minimum inhibitory concentration values of β-lactams were found to be increased in isolates from patients with chronic bronchitis who had been repeatedly administered antibiotics. Genetic analysis using PCR suggested that this might be associated with a high frequency of β-lactamase-negative strains with mutations in PBP-3. The presence of β-lactum-resistant strains needs to be considered for patients with chronic bronchitis in whom H. influenzae is isolated as a causative pathogen. [ABSTRACT FROM AUTHOR]

Aims: To investigate the prevalence of integrons and antimicrobial resistance genes in Salmonella recovered from animals in Japan. Methods and Results: Forty-eight out of ninety-four (51·1%) Salmonella isolates showed multidrug resistance phenotypes and harboured at least one antimicrobial resistance gene. Twenty-two out of forty-seven (46·8%) Salmonella enterica serovar Typhimurium that were multidrug-resistant were of definitive phage type DT104. Class 1 integrons were identified in 34/94 isolates (36·2%): 21 isolates containing two gene cassettes, aadA2 and blaPSE–1, and 13 containing one gene cassette, aadA1, aadA2 or blaPSE–1. Class 2 integrons containing estX- sat2- aadA1 gene cassettes were only identified in Salmonella Enteritidis. The β-lactamase-encoding gene, blaTEM, was only detected in S. Typhimurium. The plasmid-mediated quinolone resistance gene, qnrS1, was identified in S. Typhimurium and Salmonella Thompson. Conclusions: Our results characterized integrons and antimicrobial resistance genes in Salmonella of animal origin. To the best of our knowledge, this is the first report of qnrS in Salmonella from Japan and also the first report of qnrS in S. Thompson. Significance and Impact of the Study: Little is known about the molecular basis of antimicrobial resistance in Salmonella isolated from animals. This study provides useful data on the incidence of integrons and resistance genes in Salmonella of animal origin. [ABSTRACT FROM AUTHOR]

Introduction . Capnocytophaga species are common inhabitants of the oral cavity and can be responsible for systemic diseases in immunocompromised patients with granulocytopenia. Furthermore, it has been reported that some clinical isolates of Capnocytophaga Information is lacking about the types of β-lactamase genes possessed by Gap statement. Information is lacking about the types of β-lactamase genes possessed by Capnocytophaga spp. possessing each β-lactamase gene. Capnocytophaga The aim of this study was to investigate the presence of β-lactamase genes in clinical strains of β-lactamase-producing Aim. The aim of this study was to investigate the presence of β-lactamase genes in clinical strains of β-lactamase-producing Capnocytophaga The β-lactamase-producing Methodology. The β-lactamase-producing Capnocytophaga species ( n =49) were obtained from clinical specimens. PCR assays were used to detect bla CfxA , bla CSP , bla TEM , bla CepA/CblA and transposon Tn 4555 genes. Southern hybridization assays were used to detect bla CfxA and bla CSP . The minimum inhibitory concentration of some β-lactams was determined using the E-test method. Results. PCR analysis indicated that the bla CfxA gene. All the β-lactamase-producing bla CSP gene in 35 (69.3 %) of the 49 Capnocytophaga strains investigated, . Both bla gene in Japan. The presence of the CfxA and bla CSP genes were detected in a Capnocytophaga gingivalis strain. The PCR results were confirmed by Southern hybridization assays. Transposon Tn 4555 β-lactamase genes among Capnocytophaga spp. harbouring the bla CfxA gene. All the β-lactamase-producing Capnocytophaga isolates were susceptible to ceftazidime-clavulanic acid, cefoxitin and imipenem. In contrast, most of the isolates were resistant to amoxicillin. Conclusions. The clinical isolates of Capnocytophaga spp. showed a high prevalence of the bla CSP gene in Japan. The presence of the bla CSP gene was distributed in Capnocytophaga sputigena as well as other Capnocytophaga spp. These results seem to suggest the dissemination of bla CfxA and bla CSP β-lactamase genes among Capnocytophaga species.

Background: To clarify the molecular epidemiology of carbapenem-resistant Enterobacter cloacae complex (CREC) and the risk factors for acquisition of carbapenemase-producing E. cloacae complex (CPEC)., Methods: Using clinical CREC isolates detected in a Japanese university hospital over 4 years, carbapenemase production was screened with phenotypic methods. Carbapenemase genes were analysed by PCR and sequencing. Molecular epidemiological analyses were conducted with repetitive extragenic palindromic (REP)-PCR and multilocus sequence typing (MLST). CRECs were identified to the subspecies level by hsp60 sequencing. Whole-genome sequencing of plasmids was conducted. A case-control study was performed to identify risk factors for acquisition of CPEC among patients with CREC., Results: Thirty-nine CRECs including 20 CPECs carrying bla IMP-1 were identified. Patients with CPEC had longer hospital stay before detection (26.5 days vs. 12 days, p  = 0.008), a urinary catheter (odds ratio [OR], 5.36; 95% confidence interval [CI], 1.14-30.9; p  = 0.023), or intubation (OR, 7.53; 95% CI, 1.47-53.8; p  = 0.008) compared to patients without CPEC. Four genetically closely related CPEC clusters were observed, which showed that three of four CPEC clusters corresponded to E. asburiae (ST 53), E. hormaechei subsp. steigerwaltii (ST 113 and ST 1047) and E. cloacae subsp. cloacae (ST 513) by MLST and hsp60 sequencing. Seven representative plasmids shared structures with class I integron containing bla IMP-1 and IncHI2A replicon type., Conclusions: A longer hospital stay, presence of a urinary catheter, and intubation are risk factors for CPEC acquisition. In addition to horizontal transmission of genetically indistinguishable CPECs, IncHI2A plasmid carrying bla IMP-1 appeared to be transferred among genetically different ECs., Competing Interests: Competing interestsThe authors declare that they have no competing interests.

Purpose: The prevalence of antimicrobial-resistant bacteria, especially cephalosporin-resistant Enterobacteriaceae, is a major concern for human and animal health. We investigated the prevalence of cephalosporin-resistant Enterobacteriaceae among sheltered dogs and cats with various backgrounds., Method: Faecal samples or rectal swabs were collected from 151 dogs and 182 cats, and screened for the presence of antimicrobial-resistant bacteria. Isolates were characterized phenotypically and genotypically by pulsed-field gel electrophoresis, multi-locus sequence typing and phylogenetic grouping. The animal attributes related to bacterial carriage were statistically analysed., Results: Cephalosporin-resistant Enterobacteriaceae was detected in 22 dogs (14.6%) and 20 cats (11.0%): 21 were extended-spectrum β-lactamase (ESBL)-producing, 20 were AmpC-producing, and 1 was both ESBL- and AmpC-producing. Their β-lactamase genes were varied and associated with humans, animals or other origins. The genes CTX-M-14 (n=9) and CMY-2 (n=9) were dominant, but CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-15, CTX-M-24, CTX-M-27, CTX-M-55 and DHA-1 genes were also detected. Genotyping of isolates revealed that β-lactamase-producing Enterobacteriaceae had high genetic diversity. Relationships between animals harbouring cephalosporin-resistant Enterobacteriaceae and individual attributes, such as sex and nutrition type, were detected, but there was no correlation between history of human association and the presence of the bacterium in either dogs or cats., Conclusion: We found several types of cephalosporin-resistant Enterobacteriaceae distributed among companion animals with a range of individual attributes and histories in Osaka, Japan. Companion animals may play a bridging role in the circulation of antimicrobial-resistant bacteria from humans and from other origins.