Association of Neonatal Serum Creatinine Concentration with Maternal Serum Creatinine Concentration and Birth Weight.

BACKGROUND: The serum creatinine (SCr) concentration in neonates is generally high for its body size, compared to those of infants. The aim of the present study was to investigate the effect of maternal SCr on neonatal SCr through measurements of prenatal maternal SCr and neonatal SCr from birth to postnatal Day 5. In addition, postnatal changes in SCr were compared between term and preterm infants, given that few studies have addressed this topic. METHODS: The retrospective study subjects were 151 neonates whose Scr was measured consecutively from birth to postnatal Day 5 and 124 mothers whose SCr was measured prenatally. RESULTS: There were significant correlations between maternal SCr and neonatal SCr at birth (r = 0.858, p < 0.001) and on postnatal Day 1 (r = 0.235, p < 0. 001). The SCr of term infants (median 0.69 mg/dL, range 0.54 - 0.96 mg/ dL) were higher than those of preterm infants (median 0.63 mg/dL, range 0.43 - 1.23 mg/dL, p < 0.001) at birth; however, these values were reversed on postnatal Day 1 (Term: median 0.75 mg/dL, range 0.51 - 1.13 mg/dL, Pre-term: median 0.88 mg/dL, range 0.56 - 1.25 mg/dL, p < 0.001). There were differences in the timing of reaching to peak SCr between preterm and term neonates. In addition, birth weight might affect SCr concentrations after birth. CONCLUSIONS: The results of this study suggest that neonatal SCr is influenced by maternal SCr, although the effect disappears by postnatal Day 2. Moreover, glomerular filtration rate differs between term and preterm infants.

Molecular characteristics and genetic analysis of the genes related to carbapenemase, efflux pump, and outer membrane proteins in carbapenem-resistant Klebsiella pneumoniae.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a life-threatening pathogen that has not been fully investigated on a molecular basis. Therefore, the molecular mechanisms of carbapenem resistance in CRKP collected from medical institutions in Hyogo Prefecture has been analyzed. Antimicrobial susceptibilities and the presence of carbapenemase along with epidemiological analyzes using multilocus sequence typing (MLST) have been investigated. The relative expression of efflux pump genes and mutations of ompK35 and ompK36, encoding the outer membrane porin, were also assessed for their relationship with carbapenem resistance. Most of the collected 22 CRKP isolates were non-susceptible to imipenem (68.2%), meropenem (90.9%), and ertapenem (81.8%), but all 22 strains were susceptible to colistin. Twelve strains (54.5%) were detected for carbapenemase genes such as blaIMP-6. Sequence type 37 was detected by MLST in 10 strains (45.5%). Non-carbapenemase-producing strains had high resistance rates for three carbapenems, and the main cause of resistance was ompK35 mutation. In conclusion, the main cause of resistance was imipenemase metallo-ß-lactamase (IMP-6) production in carbapenemase-producing strains, and ompK35 mutation in non-carbapenemase-producing strains. Susceptibility to carbapenem did not differ in CRKP regardless of carbapenemase production, except for imipenem susceptibility. This result contributes to a more insightful understanding of the mechanisms of CRKP in Japan.

Assessment of catabolic state in infants with the use of urinary titin N-fragment.

BACKGROUND: Urinary titin N-fragment levels have been used to assess the catabolic state, and we used this biomarker to evaluate the catabolic state of infants. METHODS: We retrospectively measured urinary titin N-fragment levels of urinary samples. The primary outcome was its changes according to postmenstrual age. The secondary outcomes included differences between gestational age, longitudinal change after birth, influence on growth, and relationship with blood tests. RESULTS: This study included 219 patients with 414 measurements. Urinary titin N-fragment exponentially declined with postmenstrual age. These values were 12.5 (7.1-19.6), 8.1 (5.1-13.0), 12.8 (6.0-21.3), 26.4 (16.4-52.0), and 81.9 (63.3-106.4) pmol/mg creatinine in full, late, moderate, very, and extremely preterm infants, respectively (p < 0.01). After birth, urinary levels of titin N-fragment exponentially declined, and the maximum level within a week was associated with the time to return to birth weight in preterm infants (ρ = 0.39, p < 0.01). This was correlated with creatine kinase in full-term infants (ρ = 0.58, p < 0.01) and with blood urea nitrogen in preterm infants (ρ = 0.50, p < 0.01). CONCLUSIONS: The catabolic state was increased during the early course of the postmenstrual age and early preterm infants. IMPACT: Catabolic state in infants, especially in preterm infants, was expected to be increased, but no study has clearly verified this. In this retrospective study of 219 patients with 414 urinary titin measurements, the catabolic state was exponentially elevated during the early postmenstrual age. The use of the urinary titin N-fragment clarified catabolic state was prominently increased in very and extremely preterm infants.

Genetic analysis of ESBL-producing Klebsiella pneumoniae isolated from UTI patients in Indonesia.

INTRODUCTION: Extended spectrum beta-lactamase (ESBL)-producing Klebsiellapneumoniae is a serious concern for nosocomial infection and the emergence rate in Indonesia is higher than that in developed countries. The purpose of this study was to investigate the genetic characteristics of ESBL-producing K. pneumoniae isolated from UTI patients in Indonesia. MATERIALS AND METHODS: We collected K. pneumoniae resistant to ceftazidime or cefotaxime isolated from UTI patients in Dr. Soetomo's Academic Hospital in Surabaya, Indonesia in 2015. Ninety-four strains were identified as ESBL-producing bacteria by confirmation tests. The isolates were investigated by antimicrobial susceptibility testing with 20 drugs and ESBL gene detection, plasmid replicon typing and virulence genes as hypermucoviscous (HMV) strains were tested by the string test. RESULTS: High rates of resistance to ciprofloxacin (86.2%), tetracycline (80.9%) and nalidixic acid (78.7%) were observed. CTX-M-15 was the most common ESBL gene (89.4%), 33 of which also carried SHV-type ESBL. IncF was the most prevalent plasmid replicon typing (47.6%). Sixteen (17.0%) strains were judged as HMV, all of which had rmpA and more than half of which had fimH, uge, and wab. IncL/M was the most common replicon plasmid in the HMV strains, and the difference in the positive rate was statistically significant (p = 0.0024). CONCLUSION: This study showed the high prevalence of multiple-drug resistant and predominately CTX-M-15-positive ESBL-producing K. pneumoniae in Indonesia. There was a correlation between IncL/M and the HMV phenotype in this study. As such hypervirulent strains continue to emerge, studying their dissemination with resistance determinants is an urgent priority.

Cross-Resistance and the Mechanisms of Cephalosporin-Resistant Bacteria in Urinary Tract Infections Isolated in Indonesia.

Urinary tract infection (UTI) by antibiotic-resistant strains has become increasingly problematic, with trends that differ from country to country. This study examined cross-resistance and the mechanisms of cephalosporin resistance in UTI-causative bacteria isolated in Indonesia. Antibiotic susceptibility tests based on Clinical Laboratory Standards Institute (CLSI) standards were done for UTI-causative strains (n = 50) isolated from patients in Indonesia in 2015-2016 and showed resistance against the third-generation cephalosporin. Mechanistic studies were carried out to confirm the presence of extended-spectrum ß-lactamase (ESBL) genes, carbapenemase-related genes, the fosA3 gene related to fosfomycin resistance, and mutations of quinolone-resistance-related genes. Isolated UTI-causative bacteria included Escherichia coli (64.0%), Pseudomonas aeruginosa (16.0%), Klebsiella pneumoniae (10.0%), and others (10.0%). These strains showed 96.0% susceptibility to amikacin, 76.0% to fosfomycin, 90.0% to imipenem, 28.0% to levofloxacin, 92.0% to meropenem, and 74.0% to tazobactam/piperacillin. ESBL was produced by 68.0% of these strains. Mechanistic studies found no strains with carbapenemase genes but 6.0% of strains had the fosA3 gene. Seventy-two % of the strains had mutations in the gyrA gene and 74.0% in the parC gene. Most E. coli strains (87.5%) had Ser-83 → Leu and Asp-87 → Asn in gyrA and 93.8% of E. coli had Ser-80 → Ile in parC. There were significant correlations among mutations in gyrA and parC, and fosA3 gene detection (P < 0.05), respectively. To our knowledge, this is the first mechanistic study of antibiotic-cross-resistant UTI-causative bacteria in Indonesia. Further studies with a longer period of observation are necessary, especially for changes in carbapenem resistance without carbapenemase-related genes.

Differential effects of chromosome and plasmid blaCTX-M-15 genes on antibiotic susceptibilities in extended-spectrum beta-lactamase-producing Escherichia coli isolates from patients with urinary tract infection.

OBJECTIVES: To compare antibiotic susceptibilities between chromosomal and plasmid blaCTX-M-15 locations in urinary tract infection-causing extended-spectrum ß-lactamases-producing Escherichia coli blaCTX-M-15 isolated in Indonesia. METHODS: A total of 84 strains identified as extended-spectrum ß-lactamases-producing E. coli were isolated from patients with urinary tract infection in Indonesia in 2015. Antimicrobial susceptibility tests were performed on these strains using 18 antibiotics, and extended-spectrum ß-lactamase bla genes were detected by polymerase chain reaction. Gene localization of blaCTX-M-15 -positive strains was confirmed by Southern blot hybridization, and epidemiological typing was conducted using multilocus sequence typing. RESULTS: Of 54 strains harboring the blaCTX-M-15 gene, 27 showed localization on chromosome, 20 on plasmid, and seven on chromosome and plasmid. Most multilocus sequence typing sequence types of the 27 strains with chromosomal blaCTX-M-15 were ST405 (25.9%) and ST131 (22.2%) strains, whereas the 20 strains with plasmid-blaCTX-M-15 were mostly ST410 (55.0%). CONCLUSIONS: Extended-spectrum ß-lactamases-producing E. coli blaCTX-M-15 with plasmid genes show significantly higher resistant rates against piperacillin-tazobactam but lower resistant rates against chloramphenicol compared to chromosomal strains in Indonesian patients with urinary tract infection. Mechanistic investigations will be necessary to advance our knowledge of antimicrobial resistance in urinary tract infection.

Detection of Bacterial Infection Based on Age-Specific Percentile-Based Reference Curve for Serum Procalcitonin Level in Preterm Infants.

BACKGROUND: Considering the physiological changes in serum procalcitonin (PCT) levels in newborns due to age, we recently established an age-specific percentile-based reference curve for serum PCT level. The present study aimed to determine the best cutoff percentile line using this reference curve for the differentiation between infected and colonized preterm infants. METHODS: A total of 52 preterm infants with positive bacterial culture (9 with bacterial infection, 43 with colonization) were enrolled within the study period. The 97.5th, 95.0th, 92.5th, 90.0th, 80.0th, 70.0th, 60.0th, and 50.0th percentile lines were drawn in the reference curve. PCT levels in infected or colonized infants were used, and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. The best cutoff percentile line was determined in the receiver operating characteristic curve analysis. RESULTS: Of the 52 preterm infants, 9 were infected (5 and 4 infants with an onset of < 7 days and ≥ 7 days after birth, respectively), whereas 43 were colonized (6 and 37 infants with an onset of < 7 days and ≥ 7 days after birth, respectively). The best cutoff percentile lines were the 90.0th percentile (sensitivity, 0.800; specificity, 0.833; PPV, 0.800; NPV, 0.833) and 97.5th percentile (sensitivity, 1.00; specificity, 0.973; PPV, 0.800; NPV, 1.00) in infants with an onset of < 7 days and ≥ 7 days after birth, respectively. CONCLUSIONS: The age-specific percentile-based reference curve for serum PCT level is clinically applicable as a new tool for diagnosing infections in preterm infants with positive culture results, particularly at ≥ 7 days after birth.

A Novel Method for Measuring Serum Unbound Bilirubin Levels Using Glucose Oxidase-Peroxidase and Bilirubin-Inducible Fluorescent Protein (UnaG): No Influence of Direct Bilirubin.

The glucose oxidase-peroxidase (GOD-POD) method used to measure serum unbound bilirubin (UB) suffers from direct bilirubin (DB) interference. Using a bilirubin-inducible fluorescent protein from eel muscle (UnaG), a novel GOD-POD-UnaG method for measuring UB was developed. Newborn sera with an indirect bilirubin/albumin (iDB/A) molar ratio of <0.5 were classified into four groups of DB/total serum bilirubin (TB) ratios (<5%, 5-10%, 10-20%, and ≥20%), and the correlation between the UB levels and iDB/A ratio was examined. Linear regression analysis was performed to compare UB values from both methods with the iDB/A ratio from 38 sera samples with DB/TB ratio <5% and 11 samples with DB/TB ratio ≥5%. The correlation coefficient (r) between UB values and the iDB/A ratio for the GOD-POD method was 0.8096 (DB/TB ratio <5%, n = 239), 0.7265 (5-10%, n = 29), 0.7165 (10-20%, n = 17), and 0.4816 (≥20%, n = 16). UB values using the GOD-POD-UnaG method highly correlated with the iDB/A ratio in both <5% and ≥5% DB/TB ratio sera (r = 0.887 and 0.806, respectively), whereas a low correlation (r = 0.428) occurred for ≥5% DB/TB ratio sera using the GOD-POD method. Our GOD-POD-UnaG method can measure UB levels regardless of the presence of DB.

Difference of Phenotype and Genotype Between Human and Environmental: Isolated Vibrio cholerae in Surabaya, Indonesia.

Cholera due to Vibrio cholerae has been spreading worldwide, although the reports focusing on Indonesian V. cholerae are few. In this study, in order to investigate how V. cholerae transmitted to human from environment. We extended an epidemiological report that had investigated the genotype of V. cholerae isolated from human pediatric samples and environmental samples. We examined 44 strains of V. cholerae isolated from pediatric diarrhea patients and the environment such as shrimps or oysters collected in three adjacent towns in Surabaya, Indonesia. Susceptibilities were examined for 11 antibiotics. Serotype O1 or O139 genes and pathogenic genes including cholera toxin were detected. Multi-locus sequence typing (MLST) and enterobacterial repetitive intergenic consensus (ERIC)-PCR were also performed to determine genetic diversity of those isolates. Serotype O1 was seen in 17 strains (38.6%) with all pathogenic genes among 44 isolates. Other isolates were non-O1/non-O139 V. cholerae. Regarding antibiotic susceptibilities, those isolates from environmental samples showed resistance to ampicillin (11.4%), streptomycin (9.1%) and nalidixic acid (2.3%) but those isolates from pediatric stools showed no resistance to those 3 kinds of antibiotics. MLST revealed sequence type (ST) 69 in 17 strains (38.6%), ST198 in 3 strains (6.8%) and non-types in 24 strains (54.5%). All the ST69 strains were classified to O1 type with more than 95% similarity by ERIC-PCR, including all 6 (13.6%) isolates from environmental samples with resistance to streptomycin. In conclusion, V. cholerae O1 ST69 strains has been clonally spreading in Surabaya, exhibiting pathogenic factors and antibiotic resistance to streptomycin, especially in the isolates from environment.

Clonal expansion and spread of the ceftriaxone-resistant Neisseria gonorrhoeae strain FC428, identified in Japan in 2015, and closely related isolates.

OBJECTIVES: Ceftriaxone resistance in Neisseria gonorrhoeae is a major public health concern globally because a high-dose (1 g) injection of ceftriaxone is the only remaining option for empirical monotherapy of gonorrhoea. The ceftriaxone-resistant gonococcal strain FC428, cultured in Osaka in 2015, is suspected to have spread nationally and internationally. We describe the complete finished genomes of FC428 and two closely related isolates from Osaka in 2015, and examine the genomic epidemiology of these isolates plus three ceftriaxone-resistant gonococcal isolates from Osaka and Hyogo in 2016-17 and four ceftriaxone-resistant gonococcal isolates cultured in 2017 in Australia, Canada and Denmark. METHODS: During 2015-17, we identified six ceftriaxone-resistant gonococcal isolates through our surveillance systems in Kyoto, Osaka and Hyogo. Antimicrobial susceptibility testing (six antimicrobials) was performed using Etest. Complete whole-genome sequences of the first three isolates (FC428, FC460 and FC498) from 2015 were obtained using PacBio RS II and Illumina MiSeq sequencing. The three complete genome sequences and draft genome sequences of the three additional Japanese (sequenced with Illumina MiSeq) and four international ceftriaxone-resistant isolates were compared. RESULTS: Detailed genomic analysis suggested that the Japanese isolates (FC428, FC460, FC498, KU16054, KM383 and KU17039) and the four international MLST ST1903 isolates from Australia, Canada and Denmark formed four linked subclades. CONCLUSIONS: Using detailed genomic analysis, we describe the clonal expansion of the ceftriaxone-resistant N. gonorrhoeae strain FC428, initially identified in 2015 in Japan, and closely related isolates. FC428 and its close relatives show some genomic diversity, suggesting multiple genetic subclades are already spreading internationally.

Acquisition of antimicrobial-resistant variants in repeated infections caused by Pseudomonas aeruginosa revealed by whole genome sequencing.

Pseudomonas aeruginosa, responsible for serious nosocomial-acquired infections, possesses intrinsic antibiotic resistance mechanisms and commonly exhibits multidrug resistance. Here, we report the evolving resistance profiles of strains isolated from the sputum of a patient being treated for repeated P. aeruginosa infections following cancer resection. Whole genome sequencing of six isolates obtained over a 2-month period revealed two key single nucleotide polymorphisms in the mexR and gyrB genes that affected efflux pump expression and antimicrobial resistance.

Clinical Risk Factors for Death Caused by Extended-Spectrum Beta-Lactamase: Producing Bacteria.

OBJECTIVES: Extended-spectrum beta-lactamase (ESBL)-producing bacteria often causes bacteremia, leading serious outcomes. In this study, we conducted a retrospective analysis to identify the risk factors associated with death by bacteremia of ESBL-producing bacteria. METHODS: Patients with bacteremia by ESBL-producing bacteria were retrospectively collected in Kobe University Hospital, Japan, between January 2011 and December 2015. Potential risk factors for death caused by ESBL-bacteremia were analyzed for patients' outcome (recovery or death) by univariate and multivariate analysis. RESULTS: A total of 101 patients (64 male and 37 female) were recruited. The most frequently detected ESBL-producing bacteria were Escherichia coli (91 cases; 90.1%), followed by Klebsiella pneumoniae (8 cases; 7.9%). Most frequently used antibiotics after the detection of bacteremia was meropenem (66.3%; 67/101) followed by cefmetazole (51.5%; 52/101). Univariate analysis showed a significantly positive correlation with mortality in ICU admission (p < 0.001), circulatory diseases (p = 0.022), shock (p = 0.044), and respirator requirement (p = 0.002). Multivariate analysis showed ICU admission remained significant risk factor for mortality (p = 0.0192). CONCLUSIONS: We showed ICU admission was significantly correlated with death from bacteremia by ESBL-producing bacteria. These factors should be monitored to estimate severity of ESBL causing-bacteremia for better patients' outcomes.

Molecular characteristics of carbapenem-resistant Pseudomonas aeruginosa isolated from urine in Hyogo, Japan.

OBJECTIVES: To investigate the molecular characteristics and epidemiology of metallo-ß-lactamase-producing Pseudomonas aeruginosa from urine of urinary tract infection patients in Hyogo Prefecture, Japan. METHODS: Carbapenem-resistant P. aeruginosa isolated from the urine of 21 urinary tract infection patients in three general hospitals in Hyogo Prefecture (Japan) were collected between 2007 and 2014. Their antibiotic susceptibilities, metallo-ß-lactamase screening test, metallo-ß-lactamase gene sequencing, multilocus sequence typing and repetitive-sequence-based polymerase chain reaction were determined for epidemiological analyses to investigate the genetic characteristics. RESULTS: Out of 21 isolates, 13 (61.9%) were positive for metallo-ß-lactamase. There were 11 (52.4%) isolates with IMP-1 in them, one (4.5%) isolate with IMP-7 and one (4.5%) isolate with VIM-1. Metallo-ß-lactamase-positive isolates were mainly identified as ST235, and metallo-ß-lactamase-negative isolates were STs 357, 277, 234, 439 and 639. Repetitive-sequence-based polymerase chain reaction showed metallo-ß-lactamase-positive isolates were grouped in eight clusters, and ST235 isolates with IMP-1 from three hospitals belonging to the identical group I, the other ST235 isolates with IMP-7 and VIM-1 were from two hospitals belonging to group II. CONCLUSIONS: Metallo-ß-lactamase-positive P. aeruginosa of ST235 isolates with IPM-1 were mainly identified from the urine of urinary tract infection patients in Hyogo, Japan. A ST235 isolate with VIM-1 was found for the first time. Further investigation is necessary to follow the spread of metallo-ß-lactamase-positive isolates.

Bacteremia complicating urinary tract infection by Pseudomonas aeruginosa: Mortality risk factors.

OBJECTIVES: To examine the clinical risk factors for death within 30 days of diagnosis of Pseudomonas aeruginosa-causing bacteremia after a urinary tract infection. METHODS: A total of 62 patients with Pseudomonas aeruginosa isolated from both urine and blood at the same episode from January 2009 to December 2016 were enrolled in the present study. We retrospectively investigated clinical risk factors for death by comparison between surviving patients and those who died within 30 days after diagnosis of P. aeruginosa bacteremia. The comparison for risk factors for bacteremia-related death included 31 categories, such as age, laboratory data, underlying diseases, clinical history, history of surgery, care in the intensive care unit, P. aeruginosa susceptibility to the antibiotics used at the time of bacteremia diagnosis and consultation with urological department. RESULTS: The study included 48 men and 14 women aged 71.3 ± 10.4 years. Nine patients (14.5%) died of P. aeruginosa bacteremia. Statistical analysis showed that non-survivors had significantly lower albumin levels than survivors (2.07 ± 0.62 vs 2.62 ± 0.65; P = 0.023). The non-survivors had significantly higher rates of ventilator use, history of heart disease, septic shock and lower rates of consultation with urological departments after diagnosis (P < 0.05). CONCLUSIONS: Patients with bacteremia complicating urinary infection by P. aeruginosa have a low death rate. Earlier intervention by urologists might improve patients' outcome. Lower albumin levels, ventilator use, history of heart disease and septic shock are factors associated with higher mortality rate.

Prevalence of Quinolone Resistance of Extended-Spectrum ß-Lactamase-Producing Escherichia coli with ST131-fimH30 in a City Hospital in Hyogo, Japan.

Extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli isolates are known to tolerate superior quinolone antimicrobials compared with other antibacterial agents. Among the clones belonging to sequence type (ST) 131 by multilocus sequence typing, the involvement of the H30-Rx subclone has been reported worldwide with various fimH genes encoding type 1 pili. We investigated 83 isolates of ESBL-producing E. coli and performed antimicrobial susceptibility test, CH (fumC/fimH) ST131 by typing the specific PCR. Moreover, mutation analysis of genes involved in quinolone antibiotic resistance (gyrA and parC) and ESBL genotypes were determined. As a result, 54 of 83 isolates (65.1%) of CH40-30 clones corresponding to ST131-fimH30 were detected, and all were resistant to levofloxacin. Mutations associated with this resistance were common, and included S83L and D87N of gyrA and S80I and E84V of parC. Subclone analysis revealed a high proportion of fimH30-non-Rx (40 isolates, 74.1%). Each subclone was characterized by ESBL genotype, and the CTX-M-15 type was mainly seen for fimH30-Rx, with the CTX-M-14 type or CTX-M-27 type seen for fimH30-non-Rx. This study suggests that an increase in ESBL-producing quinolone-resistant E. coli in a city hospital in Hyogo, Japan, was caused by the spread of subclones belonging to fimH30-non-Rx of ST131.

Risk factors for death from Stenotrophomonas maltophilia bacteremia.

PURPOSE: Stenotrophomonas maltophilia has low pathogenicity potential, but if it causes bacteremia it can be fatal, because it has shown high resistance to many antibiotics and can be difficult to treat. Patient death from S. maltophilia bacteremia has increased since 2014 in our hospital. In this study, we investigated risk factors for death due to S. maltophilia bacteremia. METHODS: Seventy patients from the hospital database with S. maltophilia bacteremia between January 2010 and July 2017 were investigated. We retrospectively analyzed risk factors including gender, age, wards, hospitalized duration, clinical history, devices, source of S. maltophilia identification, polymicrobial bacteremia, prior antimicrobial therapy, antimicrobial therapy after bacteremia, and resistance to antibiotics. The statistical analysis was performed to compare the period from 2010 to 2013 to from 2014 to 2017. RESULTS: Comparing the 2010-2013 period to the 2014-2017 period, it revealed that history of hospitalization, identification of S. maltophilia from sputum, polymicrobial bacteremia, prior carbapenem use, and mortality was significantly different in S. maltophilia bacteremia (p = 0.028, p = 0.004, p < 0.001, p = 0.034, and p = 0.007, respectively). Comparison between non-survivors and survivors for 2010-2013 and 2014-2017 found ICU admission and ventilator use were seen more often in non-survivors (p = 0.030 vs p = 0.013 and p = 0.027 vs p = 0.010, respectively). CONCLUSIONS: Our analyses showed increase in mortality from S. maltophilia bacteremia from 2014 to 2017, and that non-survivors had a higher frequency of ICU admission and ventilator use in both the 2010-2013 and 2014-2017 periods. There were more combination antimicrobial therapy cases after bacteremia in 2014-2017. Further prospective studies with larger numbers of patients should be undertaken for definitive conclusions.

Molecular epidemiologic study of Clostridium difficile infections in university hospitals: Results of a nationwide study in Japan.

We conducted a nationwide molecular epidemiological study of Clostridium difficile infection (CDI) in Japan investigated the correlation between the presence of binary toxin genes and CDI severity. This is the first report on molecular epidemiological analyses for CDI in multiple university hospitals in Japan, to our knowledge. We examined 124,484 hospitalized patients in 25 national and public university hospitals in Japan between December 2013 and March 2014, investigating antimicrobial susceptibilities and toxin-related genes for C. difficile isolates from stools. Epidemiological genetic typing was performed by PCR-ribotyping and repetitive sequence-based (rep)-PCR to examine the genetic similarities. The results detected toxin A-positive, toxin B-positive, binary toxin-negative (A+B+CDT-) detected from 135 isolates (80.8%) and toxin A-negative, toxin B-positive, binary toxin-negative (A- B+CDT-) in 23 (13.8%). Toxin A-positive, toxin B-positive, and binary toxin-positive (A+B+CDT+) were seen in 9 isolates (5.4%). Vancomycin (n = 81, 37.7%) or metronidazole (n = 88, 40.9%) therapies were undertaken in analyzed cases. Ribotypes detected from isolates were 017/subgroup 1, 070, 078, 126, 176, 449, 475/subgroup 1, 499, 451, 566 and newtypes. Rep-PCR classified 167 isolates into 28 cluster groups including 2-15 isolates. In addition, 2 pairs of strains isolated from different institutions belonged to the same clusters. Seven out of 9 (77.8%) of the patients with binary toxin producing strains had "mild to moderate" outcome in evaluated symptoms. In conclusion, we found that binary toxin did not show regional specificity and had no relevance to severity of CDI.

Occurrence and characterization of carbapenem-resistant Gram-negative bacilli: A collaborative study of antibiotic-resistant bacteria between Indonesia and Japan.

OBJECTIVES: To explore the occurrence and characterization of carbapenemase-producing pathogens among carbapenem-resistant Gram-negative bacilli isolated from hospitalized patients with urinary tract infection in Indonesia. METHODS: This was a study promoted by the Japanese-Indonesian collaborative research program in the Japan Initiative for Global Research Network on Infectious Diseases. Bacterial pathogens were prospectively isolated from urine specimens of hospitalized urinary tract infection patients at Dr. Soetomo Hospital (Surabaya, Indonesia). All Gram-negative bacteria resistant to third-generation cephalosporin or carbapenem were included in this study. Carbapenemase genes were investigated for phenotype and genotype. RESULTS: In total, 1082 Gram-negative bacilli were isolated, of which 116 strains were resistant to imipenem or meropenem (carbapenem-resistant Gram-negative bacilli), and 22 strains were carbapenemase-producing Gram-negative bacilli. Carbapenemase-producing Gram-negative bacilli consisted of Acinetobacter baumannii (n = 4), Pseudomonas aeruginosa (n = 4), Klebsiella pneumoniae (n = 5), Providencia rettgeri (n = 4) and five others. The carbapenemase-producing Gram-negative bacilli included NDM-1 (n = 18, 81.8%, in Enterobacteriaceae and Acinetobacter spp.) and IMP-7 (n = 4, 18.2%, all in P. aeruginosa). Among carbapenem-resistant Gram-negative bacilli, all four P. aeruginosa were sensitive to colistin, and all six Acinetobacter spp. were sensitive to minocycline, colistin and tigecycline. Of those patients harboring carbapenemase-producing Gram-negative bacilli, 12 (54.5%) were seriously ill at the time of admission, with longer hospital stays and three deaths (13.6% mortality rate). CONCLUSIONS: Urinary tract infection-causing carbapenem-resistant Gram-negative bacilli are widely disseminated in Indonesia. The NDM-1 phenotype seems to be dominant, and it can be treated with colistin and tigecycline in most cases. Most patients harboring carbapenemase-producing Gram-negative bacilli are seriously ill, have a bad prognosis, with a longer hospital stay and a significant mortality rate.

Azithromycin resistance and its mechanism in Neisseria gonorrhoeae strains in Hyogo, Japan.

Therapeutic options are limited for Neisseria gonorrhoeae infection, especially for oral drugs. The purpose of this study was to investigate the susceptibility of N. gonorrhoeae to oral azithromycin (AZM) and the correlation between AZM resistance-related gene mutations and MIC. We examined the AZM MICs of clinical strains of N. gonorrhoeae, sequenced the peptidyltransferase loop in domain V of 23S rRNA, and investigated the statistical correlation between AZM MIC and the presence and number of the mutations. Among 59 N. gonorrhoeae strains, our statistical data showed that a deletion mutation was seen significantly more often in the higher-MIC group (0.5 µg/ml or higher) (35/37; 94.6%) than in the lower-MIC group (0.25 µg/ml or less) (4/22; 18.2%) (P < 0.0001). However, a mutation of codon 40 (Ala → Asp) in the mtrR gene (helix-turn-helix) was seen significantly more often in the lower-MIC group (12/22; 54.5%) (P < 0.0001). In N. gonorrhoeae multiantigen sequence typing (NG-MAST) analyses, ST4777 was representative of the lower-MIC group and ST1407, ST6798, and ST6800 were representative of the higher-MIC group. NG-MAST type 1407 was detected as the most prevalent type in AZM-resistant or -intermediate strains, as previously described. In conclusion, a deletion mutation in the mtrR promoter region may be a significant indicator for higher MIC (0.5 µg/ml or higher). ST4777 was often seen in the lower-MIC group, and ST1407, ST6798, and ST6800 were characteristic of the higher-MIC group. Further research with a greater number of strains would help elucidate the mechanism of AZM resistance in N. gonorrhoeae infection.

BACTERIAL IDENTIFICATION USING SSRA ENCODING TRANSFER-MESSENGER RNA.

Abstract. Ribosomal DNA (rDNA) sequences are widely used for phylogenetic and bacterial identification. However, rDNA of different species often reveals similar or identical same sequences. This study employed the bacterial stable small RNA (ssrA) gene encoding transfer-messenger RNA (tmRNA) as a tool for identification of Staphylococcus aureus, Enterococcus spp, Pseudomonas spp and Enterobacteriaceae from clinical isolates as representative groups using PCR and species specific primers. The method correctly identified 11 standard strains and 99 clinical isolates. Quantitative PCR revealed a limit of detection of 10(-5) µg of DNA for S. aureus and Enterococcus spp, and 10(-6) µg for Pseudomonas spp and Enterobacteriaceae. Further studies with a greater number of bacteria especially from clinical samples will need to be undertaken before this bacterial molecular marker can be applied in a clinical setting.