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RationaleAcute respiratory distress syndrome (ARDS) is a lethal complication of severe bacterial pneumonia due to the inability to dampen overexuberant immune responses without compromising pathogen clearance. Both of these processes involve tissue-resident and bone marrow (BM)–recruited macrophage (MΦ) populations which can be polarised to have divergent functions. Surprisingly, despite the known immunomodulatory properties of mesenchymal stem cells (MSCs), simultaneous interactions with tissue-resident and recruited BMMΦ populations are largely unexplored.ObjectivesWe assessed the therapeutic use of human placental MSCs (PMSCs) in severe bacterial pneumonia with elucidation of the roles of resident alveolar MΦs (AMΦs) and BMMΦs.MethodsWe developed a lethal, murine pneumonia model using intratracheal infection of a clinically relevantKlebsiella pneumoniae(KP) strain with subsequent intravenous human PMSC treatment. Pulmonary AMΦ and recruited BMMΦ analyses, histological evaluation, bacterial clearance and mice survival were assessed. To elucidate the role of resident AMΦs in improving outcome, we performed AMΦ depletion in the KP-pneumonia model with intratracheal clodronate pretreatment.Measurements and main resultsHuman PMSC treatment decreased tissue injury and improved survival of severe KP-pneumonia mice by decreasing the presence and function of recruited M1 BMMΦ while preserving M2 AMΦs and enhancing their antibacterial functions. Interestingly, PMSC therapy failed to rescue AMΦ-depleted mice with KP pneumonia, and PMSC-secreted IL-1β was identified as critical in increasing AMΦ antibacterial activities to significantly improve pathogen clearance—especially bacteraemia—and survival.ConclusionsHuman PMSC treatment preferentially rescued resident M2 AMΦs over recruited M1 BMMΦs with overall M2 polarisation to improve KP-related ARDS survival.

Background We describe the molecular epidemiology and resistance patterns of blaOXA-48 Klebsiella pneumoniae and Escherichia coli in Taiwan. Methods In this multicenter surveillance study from January 2012 to August 2015, the identified blaOXA-48 Enterobacteriaceae isolates were subjected to antibiotics susceptibility testing. PCR method was used for detecting concomitant other beta-lactamases. Outer membrane porins were analyzed. Genetic relatedness and molecular epidemiology of the isolates were determined through pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Plasmid incompatibility was determined using PCR-based replicon typing. Results Forty-three blaOXA-48 K. pneumoniae and two E. coli isolates were analyzed. The annual incidence of blaOXA-48 K. pneumoniae isolates from 2012 to 2015 were 0%, 1.1%, 2.4%, and 7.6%, respectively. Forty-three (95.5%) of 45 isolates were non-susceptible to broad-spectrum beta-lactams (ceftriaxone, ceftazidime, cefepime, piperacillin/tazobactam), Forty-two (93.3%) of the 45 isolates showed resistance against all tested carbapenems (imipenem, meropenem, doripenem, and ertapenem). Molecular characterization revealed that they co-produced at least one extended-spectrum beta-lactamases or AmpC beta-lactamases, with at least one outer membrane porin loss. Thirty-eight (88.3%) of the 43 K. pneumoniae isolates belonged to ST11. PFGE analysis of 43 K. pneumoniae isolates revealed dissemination of multiple clones. Six of the 12 tested K. pneumoniae representatives of different pulso-types belonged to IncA/C. Conclusion Concomitant loss of porins and production of other beta-lactamases renders the blaOXA-48-producing isolates in Taiwan a high-level carbapenem resistance and broad resistance against many beta-lactam antibiotics. Following dissemination of multiple clones of blaOXA-48 K pneumoniae ST 11, a trend of increased blaOXA-48 prevalence was noted.

We report the first clinical Escherichia coli strain EC3000 with concomitant chromosomal colistin and carbapenem resistance. A novel in-frame deletion, Δ6-11 (RPISLR), in pmrB that contributes to colistin resistance was verified using recombinant DNA techniques. Although being less fit than the wild-type (WT) strain or EC3000 revertant (chromosomal replacement of WT pmrB in EC3000), a portion of serially passaged EC3000 strains preserving colistin resistance without selective pressure raises the concern for further spread.

Acute respiratory distress syndrome (ARDS) is a lethal complication of severe bacterial pneumonia due to the inability to dampen overexuberant immune responses without compromising pathogen clearance. Both of these processes involve tissue-resident and bone marrow (BM)-recruited macrophage (MΦ) populations which can be polarised to have divergent functions. Surprisingly, despite the known immunomodulatory properties of mesenchymal stem cells (MSCs), simultaneous interactions with tissue-resident and recruited BMMΦ populations are largely unexplored.We assessed the therapeutic use of human placental MSCs (PMSCs) in severe bacterial pneumonia with elucidation of the roles of resident alveolar MΦs (AMΦs) and BMMΦs.We developed a lethal, murine pneumonia model using intratracheal infection of a clinically relevantHuman PMSC treatment decreased tissue injury and improved survival of severe KPHuman PMSC treatment preferentially rescued resident M2 AMΦs over recruited M1 BMMΦs with overall M2 polarisation to improve KP-related ARDS survival.

Background/purpose Superspreading events (SSEs) are pivotal in the spread of SARS-CoV-2. This study aimed to investigate an SSE of COVID-19 in a hospital and explore the transmission dynamics and heterogeneity of SSE. Methods We performed contact tracing for all close contacts in a cluster. We did nasopharyngeal or throat swabbing for SARS-CoV-2 by real-time RT-PCR. Environmental survey was performed. The epidemiological and clinical characteristics of the SSE were studied. Results Patient 1 with congestive heart failure and cellulitis, who had onset of COVID-19 two weeks after hospitalization, was the index case. Patient 1 led to 8 confirmed cases, including four health care workers (HCW). Persons tested positive for SARS-CoV-2 were HCW (n = 4), patient 1's family (n = 2), an accompanying person of an un-infected in-patient (n = 1), and an in-patient admitted before the SSE (n = 1). The attack rate among the HCW was 3.2 % (4/127). Environmental survey confirmed contamination at the bed rails, mattresses, and sink in the room patient 1 stayed, suggesting fomite transmission. The index case's sputum remained positive on illness day 35. Except one asymptomatic patient, at least three patients acquired the infection from the index case at the pre-symptomatic period. The effective reproduction number (Rt) was 0.9 (8/9). Conclusion The host factor (heart failure, longer viral shedding), transmissibility of SARS-CoV-2 (Rt, pre-symptomatic transmission), and possible multiple modes of transmission altogether contributed to the SSE. Rapid response and advance deployment of multi-level protection in hospitals could mitigate COVID-19 transmission to one generation, thereby reducing its impact on the healthcare system.

Establishing a positive reporting culture, which helps medical and healthcare workers learn from errors and reduce the risks of future adverse events, is essential to fostering a culture of patient safety.The objectives of this study were to investigate the differences among the three levels of hospitals in terms of the knowledge and attitudes of hospital staff regarding the patient safety reporting system and to identify the potential factors affecting these differences.This cross-sectional study was carried out in six hospitals, including two academic medical centers, two regional hospitals, and two district hospitals. The subjects were physicians, nurses, medical technicians, and administrative staffs. Data were collected using a patient safety reporting questionnaire.Three hundred and forty-eight participants were recruited, with 348 valid questionnaires returned (response rate: 100%). The average score for knowledge of patient safety reporting was 12.76 (total possible score: 14). Age, work position, and work experience were significantly associated with knowledge of patient safety reporting (p.01). The patient safety reporting attitudes questionnaire comprised 21 items, each of which was scored using a five-point Likert scale. The mean score for each item was 3.92 ± 0.50. Gender, age, work position, work experience, and job discipline were significantly associated with attitude toward reporting (p.01). The level of hospital was found to significantly impact attitudes toward patient safety reporting (p = .01), with participants working at medical centers scoring the highest. In addition, participants who were older and in more-senior positions scored higher and more positively for both knowledge and attitudes.The key factors to successfully fostering a strong patient safety reporting culture are staff security, a reliable reporting system, and a user-friendly interface. Improving attitudes toward reporting requires more resources and time than improving knowledge of reporting, which may be improved using education and promotion. Regional hospitals may invest more resources to enhance positive attitudes toward reporting and increase the willingness of staff to report.醫院層級在病人安全事件通報態度、知識之差異.建立醫療正向通報文化，從錯誤中學習，進而預防未來異常事件發生，是病人安全文化塑造之重要基礎建設。.藉由問卷調查瞭解各層級醫院病人安全通報知識與態度的差異，找出影響因素。.本研究採橫斷式問卷調查，共收案6家醫院，含2家醫學中心、2家區域醫院、2家地區醫院，對象包括醫師、護理、醫技行政人員等，填寫「病人安全通報調查問卷表」。.本研究受試者共348名，有效問卷數為348份，回收率為100%。病人安全通報知識總分為14分，受訪者平均分數為12.76分，在年齡、職務級別及年資與通報知識達統計上顯著差異（p.01）。病人安全通報態度共21題，採李克特量表（Likert）五分法計分，平均分數為3.92 ± 0.50，在性別、年齡、職務級別、年資及職稱類別與通報態度達統計上顯著差異（p.01）。醫院層級間通報知識與通報態度，僅於通報態度有統計上顯著差異（p = .01），以「醫學中心」表現最佳。受訪者年齡越大及職務級別越高者，不論是在病人安全通報知識或態度上得分均越高。.建置優良的病人安全事件通報文化成功的關鍵在於醫療團隊人員對通報系統感到安全、信任與操作簡易方便。相較於知識可以透過教育訓練、宣導傳達人員，通報態度需要花費較多資源與時間，區域醫院可考慮投入更多資源，提升正向通報態度，進而增加人員通報意願。.

We report the first clinical Escherichia coli strain EC3000 with concomitant chromosomal colistin and carbapenem resistance. A novel in-frame deletion, Δ6-11 (RPISLR), in pmrB that contributes to colistin resistance was verified using recombinant DNA techniques. Although being less fit than the wild-type (WT) strain or EC3000 revertant (chromosomal replacement of WT pmrB in EC3000), a portion of serially passaged EC3000 strains preserving colistin resistance without selective pressure raises the concern for further spread.

Background This study describes an outbreak caused by imipenem-resistant Acinetobacter baumannii (IRAB) involving 2 general wards at the Penghu branch of Tri-Service General Hospital. Methods Clinical data obtained from the patients with IRAB during an outbreak from May 2014-October 2014 were reviewed. Microbiologic sampling from the environment and the hands of health care workers (HCWs) was performed. Clinical isolates from case patients were genotyped using pulsed-field gel electrophoresis (PFGE). Results During the outbreak period, 12 patients were colonized or infected with IRAB. The hospital room environments of the case patients were contaminated with IRAB. Hands of nurses and physicians were not colonized with IRAB, but the hands of 2 bedside caregivers of case patients were colonized with IRAB. The PFGE analysis revealed that at least 2 major genetically distinct strains disseminated between 2 different wards. After implementation of infection control measures with a cohort of nursing patients, hand hygiene education for caregivers who had not received instructions before the outbreak, and a critical value alert system to notify case patients, the outbreak was controlled successfully. Conclusions This outbreak study highlights the importance of adherence to hand hygiene by all HCWs to prevent the dissemination of multidrug-resistant organisms.

We describe the molecular epidemiology and resistance patterns of blaIn this multicenter surveillance study from January 2012 to August 2015, the identified blaForty-three blaConcomitant loss of porins and production of other beta-lactamases renders the bla

Background/purposeThe emergence of Klebsiella pneumoniae carbapenemase (KPC)-producing strains is a challenge for clinicians. The characteristics and virulence of variants of KPC-producing K. pneumoniae isolates were evaluated.MethodsFive clinical isolates—three KPC subtypes from Taiwan (KPC2-TW, KPC3-TW, and KPC17-TW) and two clinical strains from the United States (US; KPC2-US, KPC3-US)—were included. Virulent traits and capsular serotypes were analyzed by Polymerase Chain Reaction (PCR). Serum killing, neutrophil phagocytosis, and mice lethargy studies were performed to evaluate virulence.ResultsMultilocus sequence typing (MLST) demonstrated that KPC2-TW and KPC17-TW belonged to sequence type (ST)11, and KPC2-US, KPC3-US, and KPC3-TW to ST258. KPC3-TW expressed capsular serotype K1, whereas the others were non-K1/K2/K5 isolates. MLST analysis indicated that ST11 strains were serum resistant, whereas ST258 isolates were serum sensitive. ST11 isolates exhibited significantly higher 15-minute phagocytic rates than ST258 isolates (70.28 ± 16.68% vs. 34.88 ± 10.52%, p 107 CFU. Immunological responses were not significantly correlated with KPC subtype; however, responses were associated with MLST and capsular serotype.ConclusionProduction of KPC itself was not associated with increased virulence despite different variants of KPC. The ST11 KPC-producing strain was resistant to serum killing, whereas capsular ss K1 was associated with resistance to neutrophil phagocytosis.

Summary Hypervirulent Klebsiella pneumoniae (hvKP) causes severe infections even in healthy individuals by escaping surveillance and killing from polymorphonuclear neutrophils (PMNs), the first-line leukocytes in bacterial infections; moreover, the emergence of multidrug-resistant strains further limits treatment options. We therefore assess whether multilineage mesenchymal stem cells (MSCs), best known for immunomodulation toward T cells, could be therapeutic for highly virulent bacterial infections via modulation of PMNs. We find that both bone marrow MSCs and placental MSCs (PMSCs) preserve in vitro PMN survival, but only PMSCs significantly enhance multiple PMN bactericidal functions, including phagocytosis, through secretion of interleukin-1β (IL-1β). PMSC treatment of hvKP-infected mice suppresses T and natural killer (NK) cell responses as expected but can preferentially recruit PMNs and enhance antibacterial functions to allow for disease survival; IL-1β knockdown in PMSCs significantly decreases hvKP clearance, worsening survival and resulting in 100% lethality. Our data strongly implicate the possible use of PMSCs for infections of PMN-resistant hvKP strains.

To develop a measure of medication-related quality of life (MRQoL) and to validate the measure in a hospital-based population of patients with polypharmacy. The Medication-Related Quality of Life Scale version 1.0 (MRQoLS-v1.0) included 14 items developed on the basis of interviews with elderly patients with polypharmacy, defined as taking five or more medications simultaneously. This scale was tested in 219 outpatients (99 with polypharmacy and 120 without polypharmacy). Two measures were used to establish construct validity the Psychological Distress Checklist, for convergent validity, and the Medication Adherence Behavior Scale (MABS), for discriminant validity. The 14-item scale was found to be both reliable and valid. Internal consistency reliability evaluated using Cronbach’s alpha for this scale was 0.91. Scores on the MRQoLS-v1.0 correlated statistically significantly and negatively with those on the Psychological Distress Checklist. Discriminant validity was demonstrated by low correlation with MABS, indicating that the MRQoLS-v1.0 measured concepts different from medication adherence. Significant differences in the MRQoLS-v1.0 between patients with polypharmacy and those without polypharmacy provided evidence for known-group validity. The study presents a psychometric evaluation of a measure used to assess MRQoL of patients with polypharmacy. The instrument is practical to administer in clinics and provides a valuable adjunct to the outcome measurement for patients with polypharmacy. Further research on the sensitivity of this instrument to medication change in multi-medicated patients is warranted.

Bacterial meningitis is responsible for significant morbidity and mortality worldwide, despite that modern antibiotics effectively penetrate cerebrospinal fluid to eradicate bacteria. A clinical suspicion of bacterial meningitis should be recognized early for the rapid diagnostic workup. Bacterial meningitis associated with ventriculoperitoneal shunt (VPS) is not uncommon and infrequently presents as abdominal symptoms and signs. Infections of the central nervous system caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) are extremely rare, and such multiple drug-resistant pathogens frequently cause inappropriate treatments and mortality. β-Lactamases are bacterial enzymes that inactivate β-lactam antimicrobial agents. The increased prevalence of ESBL-producing organism infections has become a worldwide problem. Timely and appropriate treatment is important to reduce mortality and morbidity of infections caused by ESBL-producing organisms. Here, we report a 61-year-old male patient who underwent VPS implantation for consequent hydrocephalus following spontaneous intracranial hemorrhage six months before this presentation. He was admitted for intermittent fever and right lower quadrant abdominal pain, and he was initially managed as acute appendicitis with its typical presentation. Finally, he was diagnosed VPS-associated meningitis caused by ESBL-KP. This patient was successfully treated with the combination of meropenem, a carbapenem antibiotic that is the drug of choice for treating ESBL-producing organisms, and high-dose fosfomycin, a phosphonic acid derivative antibiotic that is effective in treating some drug-resistant pathogens. In the present report, we emphasize the clinical presentations of catheter-related meningitis and risk factors for infections caused by ESBL-producing pathogens. Antibiotic combination therapy can provide synergistic effect and maximize anti-bacterial activity in ESBL-KP meningitis.

The capsular polysaccharides in different serotypes of Klebsiella pneumoniae (KP) coded by the (CPS) gene cluster are characterized by a conserved and a hyper-variable region. We performed a virulence study by switching genes in the highly conserved region of the CPS cluster between strains. Six genes in the CPS conserved region in serotype K20, including galF, acidPPc, wzi, wza, wzb and wzc, were knocked out and replaced by the homologous genes from serotype K1. Compared to the parental K20 strain, the mutants showed a decline in lethality (LD50) in mice from 10-fold to > 105-fold and were categorized in terms of the effect on virulence as low (L) for galF and acidPPC, moderate (M) for wzi, and high (H) for wza, wzb and wzc. Although substituting the acidPPC gene from K1 for acidPPC in the K20 strain fully restored virulence, substitution with the wzi, wza, wzb or wzc homologs from K1 did not. The restoration with wzi from K1 led to a partial restoration of virulence, with the LD50 in mice changing from 104 to 103 CFU. For the wza, wzb and wzc genes, Complementation of K20 wza, wzb and wzc from K1 resulted in varied degrees of lethality in mice. Variable improvement in serum killing and phagocytosis was observed when the knockout mutants were compared with the gene-switched strains. In conclusion, homologous genes for capsule synthesis failed to exhibit the same functionality when switched between serotypes and virulence was decreased in different degree in according to the genes' homology.

Annually increasing rates of carbapenem-resistant Acinetobacter spp. were observed in a Taiwan hospital since its establishment in November 1998 to March 2005. Increasing consumption of carbapenems was also noticed. Carbapenem-resistant Acinetobacter spp. from 33 patients carried a class 1 integron. Twenty-eight isolates were Acinetobacter baumannii harbouring both ISAba1 and an OXA-51-like gene. Twenty-four of the 28 A. baumannii isolates had ISAba1 upstream of the OXA-51-like gene. Four A. baumannii isolates harboured the OXA-24-like gene and one isolate had the VIM-11 gene. Regarding the five non-baumannii Acinetobacter spp., three Acinetobacter genomic species 3 isolates and one Acinetobacter radioresistens isolate had both IMP-1 and OXA-58-like genes. One A. radioresistens isolate had an OXA-23-like gene. One major clone of A. baumannii (25/28; 89.3%) was identified by ribotyping. Three ribotypes were identified as being brought into the hospital by patient transfer from other hospitals. In conclusion, an insidious clonal dissemination with various resistance mechanisms contributed to the spread of carbapenem-resistant Acinetobacter spp. in a hospital setting, with increasing usage of carbapenems as the possible selection pressure. Notification of carbapenem-resistant Acinetobacter spp. infection when patients are transferred between hospitals is important to control the spread of carbapenem resistance.

4. Through the development of computer program, environment surveillance monitoring procedure is highly-efficient. Also, the establishment of standards of testing specimen can avoid contamination. Conclusions: Most departments are highly satisfied with the program because of increased work efficiency. In future, this program can be considered to contribute to inspect test results of epidemic outbreak and do ‘quality assurance’ of the medical practice directly related to infection control as well as consistent monitoring will be needed.

A total of 171 hospitals' isolates of E. coli, K. pneumoniae, and E. cloacae with a minimum inhibitory concentration (MIC) ofor =2 microg/ml for ceftazidime or cefotaxime were evaluated for the production of beta-lactamases. PCR amplification with specific primers for the bla (SHV), bla (TEM), and bla (CTX) genes revealed that a total of 53, 81, and 43 of these genes were amplified, respectively. Sequencing results confirmed that TEM-1, CTX-M-3 and -14, SHV-1, -5, -11, -12, and -33, OXY-1a, and LEN-1 were presented among these isolates. No specific large cluster of isolates carried the same beta-lactamases, indicating the wide diversity of the collected strains. Plasmid spread between E. coli and K. pneumoniae was identified in few isolates. Combinations of TEM, SHV, and CTX beta-lactamase genes, including extended-spectrum beta-lactamase genes, were observed in all three species.

To better understand the role of capsular polysaccharide (CPS) K1 or K2 in Klebsiella pneumoniae liver abscess as well as the development of metastasis to eye, neutrophil phagocytosis of 70 CPS isolates including K1 (n = 23)/K2 (n = 10), non-K1/K2 (n = 37) was evaluated by flow cytometry, fluorescence imaging, and electron microscopy. K1/K2 isolates were significantly more resistant to phagocytosis (P < 0.0001) than non-K1/K2 isolates and displayed increased resistance to intracellular killing. Although mucoid phenotype (M-type) K1/K2 isolates were significantly more resistant to phagocytosis (P = 0.0029) than M-type non-K1/K2, no significant difference in the phagocytosis rate was observed between K1/K2 isolates with M-type and non-M-type (P = 0.0924). Mucoidy is an associated factor that was predominant in K1/K2 isolates, but which itself is not an independent influence on phagocytic resistance. The K1/K2 CPS proved significantly more resistant to phagocytosis than non-K1/K2 CPS in liver abscess isolates (P < 0.0001) and non-abscess isolates (P = 0.0001), suggesting that K1/K2 isolates were generally more virulent in both liver abscess and in non-liver abscess conditions. These findings indicate that resistance of CPS K1 or K2 K. pneumoniae to phagocytosis and intracellular killing presumably contributes to their high prevalence in liver abscess and uniquely in endophthalmitis.

Objective To determine the mechanism of rifampicin resistance in Streptococcus pneumoniae in Taiwan. Methods Rifampicin resistance was investigated with respect to the rpoB gene in 23 invasive S. pneumoniae isolates collected from 1996 to 2001. PCR and molecular typing were used for genetic and epidemiological analyses. Transformation was used to determine the functional gene for resistance. Results Twenty-two of 23 isolates carried at least one mutation at either cluster I or III of rpoB; the most frequent mutation found in 21 isolates (91%) was histidine (H499) to asparagine or tyrosine at position 499, followed by isoleucine to valine (I624V) at position 624 in 16 isolates (70%), tyrosine to phenylalanine (Y589F) at position 589 in 14 isolates (60.9%) and isoleucine to valine (I608V) at position 608 in 13 isolates (56.5%). Less-frequent mutations were also identified: D489V, R597F, N623E, N623S, N669D, Q671K, Y674F and A683V. High-level rifampicin resistance was observed in isolates with a mutation at position 499 or 489. Mutations other than at position 499 or 489 played little role in or had no relation to rifampicin resistance. No dominant epidemic strain was observed with ribotyping, multilocus sequence typing, or serotyping. Conclusions Rifampicin resistance among multidrug-resistant S. pneumoniae in Taiwan was mostly caused by rpoB mutations.

Objectives Tigecycline is a treatment option for infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP). Emerging tigecycline resistance in CRKP represents a growing threat. Knowledge of the clinical, microbiological, and molecular characteristics of tigecycline- and carbapenem-resistant Klebsiella pneumoniae (TCRKP) is limited. Methods Patients infected with TCRKP were identified from a Taiwanese national surveillance study. Clinical data were collected from medical records. We performed susceptibility tests, carbapenemase gene detection, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Furthermore, we performed quantitative real-time polymerase chain reaction (qRT-PCR) analyses to assess the expression levels of the efflux pump genes acrB and oqxB. Results We identified 16 patients infected with TCRKP, with urinary tract infection (UTI) being the most common type of infection (63%). The all-cause 30-day mortality rate was 44% in patients with TCRKP infection. Patients with a site of infection other than the urinary tract had a significantly higher mortality rate than patients with UTIs (83% vs. 20%, p = 0.035). PFGE and MLST revealed no dominant clone or sequence type. Using qRT-PCR, overexpression of both the acrB and oqxB genes was identified in seven isolates, and overexpression of the oqxB gene was observed in another seven. There was poor correlation between acrB or oqxB expression and tigecycline MICs (r = -0.038 and -0.166, respectively). Conclusions The mortality rate in patients infected with TCRKP in this study was 44% and this is an important subset of patients. The absence of a linear relationship between efflux pump genes expression and MICs indicates that tigecycline resistance may be mediated by other factors. Continuous monitoring of tigecycline resistance among CRKP isolates and resistance mechanisms are necessary.

Bacterial meningitis is responsible for significant morbidity and mortality worldwide, despite that modern antibiotics effectively penetrate cerebrospinal fluid to eradicate bacteria. A clinical suspicion of bacterial meningitis should be recognized early for the rapid diagnostic workup. Bacterial meningitis associated with ventriculoperitoneal shunt (VPS) is not uncommon and infrequently presents as abdominal symptoms and signs. Infections of the central nervous system caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) are extremely rare, and such multiple drug-resistant pathogens frequently cause inappropriate treatments and mortality. β-Lactamases are bacterial enzymes that inactivate β-lactam antimicrobial agents. The increased prevalence of ESBL-producing organism infections has become a worldwide problem. Timely and appropriate treatment is important to reduce mortality and morbidity of infections caused by ESBL-producing organisms. Here, we report a 61-year-old male patient who underwent VPS implantation for consequent hydrocephalus following spontaneous intracranial hemorrhage six months before this presentation. He was admitted for intermittent fever and right lower quadrant abdominal pain, and he was initially managed as acute appendicitis with its typical presentation. Finally, he was diagnosed VPS-associated meningitis caused by ESBL-KP. This patient was successfully treated with the combination of meropenem, a carbapenem antibiotic that is the drug of choice for treating ESBL-producing organisms, and high-dose fosfomycin, a phosphonic acid derivative antibiotic that is effective in treating some drug-resistant pathogens. In the present report, we emphasize the clinical presentations of catheter-related meningitis and risk factors for infections caused by ESBL-producing pathogens. Antibiotic combination therapy can provide synergistic effect and maximize anti-bacterial activity in ESBL-KP meningitis.

Summary Background The emergence of carbapenem-resistant Acinetobacter baumannii (CRAB) was observed in a Kenyan hospital from 2009 to 2010. Further investigation of the dissemination of CRAB isolates and the molecular characterization of associated resistance determinants were therefore performed. Methods Antibiotic susceptibilities were determined by broth microdilution and Etest. Metallo-β-lactamases were detected by Etest method. Clonal relationships were studied by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). β-Lactam and aminoglycoside resistance determinants and the clonal relatedness to widespread European clones were studied by PCR and sequencing. Results Sixteen CRAB isolates from 10 patients possessed six pulsotypes; half of the isolates belonged to the European clone II (ECII) lineage. ECII strains were typed as MLST sequence type 2 (ST2) and ST109, and non-ECII strains as ST25 and ST113. All isolates harbored IS Aba1–bla OXA-23 , bla OXA-51-like , bla ADC , and class 1 integron, including one that also harbored bla NDM-1 . ADC-57 and two integron cassettes ( arr-2-cmlA5 and aadB-aadA2-cmlA6-aadA15 ) were newly-identified. Non-ECII isolates, designated non-ECII clone, carried armA and integron cassette arr-2 - cmlA5 . Conclusions Two distinct clones of CRAB – ECII and non-ECII epidemic clones – were disseminated in Kenya. The concomitance of IS Aba1 – bla OXA-23 was the major mechanism contributing to CRAB. The first identification of ECII CRAB and New Delhi metallo-β-lactamase 1 (NDM-1) extensively drug-resistant A. baumannii in East Africa is of concern.

The genetic structure of β-lactamases inAcinetobactergenospecies 3 (AG3) isolates in Taiwan was studied to analyze their high rates of resistance to β-lactams, including carbapenems (57.9%).blaIMP-1andblaIMP-8were located in a class 1 integron.blaOXA-58was bracketed by ISAba3. A novel TnpF-like integrase gene was identified upstream ofblaVEB-3. Adjacent to the 5′ sequence of theblaADCgene,folEwas identified. Four newAcinetobacter-derived cephalosporinase (ADC) enzymes were found, which clustered phylogenetically with published AG3 ADC proteins.

Bla(OXA-51-like), the intrinsic carbapenemase gene in Acinetobacter baumannii previously found only in this species, was detected in a clinical isolate of Acinetobacter genomic species 13tU. this study aimed to characterize this gene in the isolate. Genomic species identification was confirmed by amplified ribosomal DNA restriction analysis and sequence analysis of 16S-23S ribosomal DNA intergenic spacer, rpoB and recA. The bla(OXA-51-like) gene, with an upstream ISAba1 insertion, was plasmid-encoded and the surrounding sequences suggested that its origin was from A. baumannii. Transformation of Acinetobacter genomic species 13TU AtCC 17903 with recombinant plasmid bearing ISAba1-bla(OXA-51-like) from the isolate increased the minimum inhibitory concentrations (MICs) of meropenem and imipenem 256-fold. This is the first report of bla(OXA-51-like) in an organism other than A. baumannii. This plasmid-borne bla(OXA-51-like) gene with an upstream ISAba1 insertion confers a high level of carbapenem resistance to Acinetobacter genomic species 13TU.

Acinetobacter baumannii isolates containing class 1 integrons belong to different clones, but only a few strains are successful at causing infection. This study was conducted to compare the characteristics among these clones with different epidemicity.Eighty eight bacteremic isolates of A. baumannii were collected in a medical center in Taiwan during a 3-year period. The gene cassettes and antibiotic susceptibilities of the bacterial isolates were delineated and the patients' characteristics were compared.Class 1 integrons were detected in 75 isolates (85.2%). Most of the isolates belonged to 2 major clones, but only 1 of the 2 clones caused outbreaks in several hospitals in Taiwan. Restriction analyses of variable regions of the integron revealed identical gene cassettes among isolates within the same clone. The cassette arrays of the 3 clones were aacA4, catB8, aadA1 (clone I, epidemic clone); dhfr XII, unknown open reading frame (orfF), aadA2 (clone II, endemic clone); and aacC1, 2 unknown open reading frames (orfX, orfX'), aadA1a (clone III). The epidemic and endemic strains were multidrug resistant, but the former presented a higher resistance rate to ampicillin-sulbactam. Infections with epidemic strains were significantly associated with prior use of cephalosporins, but didn't contribute to a higher mortality rate.Judicious use of cephalosporins and rapid identification using the integron typing method might be helpful for the prevention of further spread of strains with epidemic potential.

In this study, we investigated the distribution of genes encoding various carbapenemases as well as their association with carbapenem resistance in clinical isolates of Acinetobacter genomic species from Taiwan. A total of 129 imipenem-non-susceptible and 79 imipenem-susceptible isolates were examined, of which 185 (88.9%) were Acinetobacter baumannii. Among the 185 A. baumannii isolates, imipenem non-susceptibility was more common in isolates with IS Aba1–bla OXA-51-like (72/75; 96%), bla OXA-58-like (33/33; 100%) or bla OXA-24-like (7/7; 100%) than in isolates with only bla OXA-51-like (4/72; 5.6%). A metallo-β-lactamase (MBL) gene was present in two isolates of imipenem-resistant A. baumannii , and bla OXA-58-like was also present in these isolates. A total of 18% and 1% of imipenem-non-susceptible isolates of A. baumannii were resistant to tigecycline and colistin, respectively. Among the 23 isolates of non- baumannii Acinetobacter spp., bla OXA-58-like and MBL genes were widely disseminated in the imipenem-resistant isolates, and isolates with bla OXA-58-like and MBL genes had higher imipenem minimum inhibitory concentrations than those with bla OXA-58-like alone. Although the rate of non-susceptibility to colistin was 26.7% among the imipenem-non-susceptible isolates of non- baumannii Acinetobacter , 93.3% and 100% were susceptible to ciprofloxacin and tigecycline, respectively. In conclusion, different isolates of imipenem-non-susceptible A. baumannii and non- baumannii Acinetobacter contained different carbapenemases and had different antimicrobial susceptibilities.

There are no previous reports of human infection due to Acinetobacter baylyi . In this study, we report on six patients with bacteremia due to A. baylyi , based on analysis of the 16S-23S rRNA intergenic spacer and the 16S rRNA gene. All six patients had multiple underlying diseases. The infection was nosocomially acquired in five patients. The six clinical isolates had similar ribopatterns, suggesting a clonal relationship. Compared to the reference strain, the clinical isolates were more resistant to antimicrobial agents, especially beta-lactam antibiotics. In three of the isolates, they may have undetermined plasmid mediated class C type beta-lactamases because of the positive results in a double-disk synergy test using 3-aminophenylboronic acid. Two of the clinical isolates retained a level of natural transformability similar to that of the reference strain. None of the patients died, although only three of them received appropriate antimicrobial therapy. This study demonstrates that A. baylyi is a potential human pathogen that can cause nosocomial infection in immunocompromised patients.

To better understand the role of capsular polysaccharide (CPS) K1 or K2 in Klebsiella pneumoniae liver abscess as well as the development of metastasis to eye, neutrophil phagocytosis of 70 CPS isolates including K1 (n = 23)/K2 (n = 10), non-K1/K2 (n = 37) was evaluated by flow cytometry, fluorescence imaging, and electron microscopy. K1/K2 isolates were significantly more resistant to phagocytosis (P0.0001) than non-K1/K2 isolates and displayed increased resistance to intracellular killing. Although mucoid phenotype (M-type) K1/K2 isolates were significantly more resistant to phagocytosis (P = 0.0029) than M-type non-K1/K2, no significant difference in the phagocytosis rate was observed between K1/K2 isolates with M-type and non-M-type (P = 0.0924). Mucoidy is an associated factor that was predominant in K1/K2 isolates, but which itself is not an independent influence on phagocytic resistance. The K1/K2 CPS proved significantly more resistant to phagocytosis than non-K1/K2 CPS in liver abscess isolates (P0.0001) and non-abscess isolates (P = 0.0001), suggesting that K1/K2 isolates were generally more virulent in both liver abscess and in non-liver abscess conditions. These findings indicate that resistance of CPS K1 or K2 K. pneumoniae to phagocytosis and intracellular killing presumably contributes to their high prevalence in liver abscess and uniquely in endophthalmitis.

In this study, 283 multidrug-resistant Acinetobacter baumannii (MDR-AB) bloodstream isolates were collected between 1996 and 2004, from three teaching hospitals located in different regions of Taiwan. Susceptibility data showed that strains carrying class 1 integrons were significantly more resistant (p

Background The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary with serotype. Method To investigate the role of K and O antigen in hyper-virulent strains, we constructed O and K antigen deficient mutants from serotype K1 STL43 and K2 TSGH strains from patients with liver abscess, and characterized their virulence in according to the abscess formation and resistance to neutrophil phagocytosis, serum, and bacterial clearance in liver. Results Both of K1 and K2-antigen mutants lost their wildtype resistance to neutrophil phagocytosis and hepatic clearance, and failed to cause abscess formation. K2-antigen mutant became serum susceptible while K1-antigen mutant maintained its resistance to serum killing. The amount of glucuronic acid, indicating the amount of capsular polysaccharide (CPS, K antigen), was inversed proportional to the rate of phagocytosis. O-antigen mutant of serotype K1 strains had significantly more amount of CPS, and more resistant to neutrophil phagocytosis than its wildtype counterpart. O-antigen mutants of serotype K1 and K2 strains lost their wildtype serum resistance, and kept resistant to neutrophil phagocytosis. While both mutants lacked the same O1 antigen, O-antigen mutant of serotype K1 became susceptible to liver clearance and cause mild abscess formation, but its serotype K2 counterpart maintained these wildtype virulence. Conclusion We conclude that the contribution of surface antigens to virulence of K. pneumoniae strains varies with serotypes.