Antibiotic Combination to Effectively Postpone or Inhibit the In Vitro Induction and Selection of Levofloxacin-Resistant Mutants in Elizabethkingia anophelis.

Fluoroquinolones are potentially active against Elizabethkingia anophelis. Rapidly increased minimum inhibitory concentrations (MICs) and emerging point mutations in the quinolone resistance-determining regions (QRDRs) following exposure to fluoroquinolones have been reported in E. anophelis. We aimed to investigate point mutations in QRDRs through exposure to levofloxacin (1 × MIC) combinations with different concentrations (0.5× and 1 × MIC) of minocycline, rifampin, cefoperazone/sulbactam, or sulfamethoxazole/trimethoprim in comparison with exposure to levofloxacin alone. Of the four E. anophelis isolates that were clinically collected, lower MICs of levofloxacin were disclosed in cycle 2 and 3 of induction and selection in all levofloxacin combination groups other than levofloxacin alone (all p = 0.04). Overall, no mutations were discovered in parC and parE throughout the multicycles inducted by levofloxacin and all its combinations. Regarding the vastly increased MICs, the second point mutations in gyrA and/or gyrB in one isolate (strain no. 1) occurred in cycle 2 following exposure to levofloxacin plus 0.5 × MIC minocycline, but they were delayed appearing in cycle 5 following exposure to levofloxacin plus 1 × MIC minocycline. Similarly, the second point mutation in gyrA and/or gyrB occurred in another isolate (strain no. 3) in cycle 4 following exposure to levofloxacin plus 0.5 × MIC sulfamethoxazole/trimethoprim, but no mutation following exposure to levofloxacin plus 1 × MIC sulfamethoxazole/trimethoprim was disclosed. In conclusion, the rapid selection of E. anophelis mutants with high MICs after levofloxacin exposure could be effectively delayed or postponed by antimicrobial combination with other in vitro active antibiotics.

Validation of 16S rRNA and Complete rpoB Gene Sequence Analysis for the Identification of Elizabethkingia Species.

Bacteria in the genus Elizabethkingia have emerged as a cause of life-threatening infections in humans. However, accurate species identification of these pathogens relies on molecular techniques. We aimed to evaluate the accuracy of 16S rRNA and complete RNA polymerase ß-subunit (rpoB) gene sequences in identifying Elizabethkingia species. A total of 173 Elizabethkingia strains with whole-genome sequences in GenBank were included. The 16S rRNA gene and rpoB gene sequences from the same Elizabethkingia strains were examined. Of the 41 E. meningoseptica strains, all exhibited >99.5% 16S rRNA similarity to its type strain. Only 83% of the 99 E. anophelis strains shared >99.5% 16S rRNA gene similarity with its type strain. All strains of E. meningoseptica and E. anophelis formed a cluster distinct from the other Elizabethkingia species in the 16S rRNA and rpoB gene phylogenetic trees. The polymorphisms of 16S rRNA gene sequences are not sufficient for constructing a phylogenetic tree to discriminate species in the E. miricola cluster (E. miricola, E. bruuniana, E. occulta, and E. ursingii). The complete rpoB gene phylogenetic tree clearly delineates all strains of Elizabethkingia species. The complete rpoB gene sequencing could be a useful complementary phylogenetic marker for the accurate identification of Elizabethkingia species.

In Vitro and In Vivo Antimicrobial Activities of Vancomycin and Rifampin against Elizabethkingia anophelis.

Elizabethkingia anophelis has emerged as a critical human pathogen, and a number of isolated reports have described the successful treatment of Elizabethkingia infections with vancomycin, a drug that is typically used to target Gram-positive bacteria. This study employed in vitro broth microdilution checkerboard and time-kill assays, as well as in vivo zebrafish animal models to evaluate the individual and combination antimicrobial effects of vancomycin and rifampin against E. anophelis. The minimum inhibitory concentration ranges of vancomycin and rifampin against 167 isolates of E. anophelis were 16-256 mg/L and 0.06-128 mg/L, respectively. The checkerboard assay results revealed a synergistic effect between vancomycin and rifampin in 16.8% (28/167) of the isolates. Time-kill assays were implemented for 66 isolates, and the two-drug combination had a synergistic interaction in 57 (86.4%) isolates. In vivo zebrafish studies revealed that treatment with vancomycin monotherapy, rifampin monotherapy, or vancomycin-rifampin combination therapy yielded a higher survival rate than the control group treatment with 0.9% saline. The results of this study support the use of vancomycin to treat E. anophelis infections.

Mutant Prevention Concentrations of Ciprofloxacin and Levofloxacin and Target Gene Mutations of Fluoroquinolones in Elizabethkingia anophelis.

Fluoroquinolones are potentially effective against Elizabethkingia anophelis. We investigated the MIC, mutant prevention concentration (MPC), and target gene mutations of fluoroquinolones in E. anophelis. Eighty-five E. anophelis isolates were collected from five hospitals in Taiwan. The MIC and MPC of ciprofloxacin and levofloxacin were examined for all E. anophelis except 17 isolates, in which ciprofloxacin MPC could not be determined due to drug precipitation caused by overly high drug concentration. Mutations in the quinolone resistance-determining regions of DNA gyrase (GyrA and GyrB) and topoisomerase IV (ParC and ParE) in the clinical isolates and fluoroquinolone-selected mutants were examined. Overall, 23.5% and 71.8% of the isolates tested were susceptible to ciprofloxacin and levofloxacin, respectively. The MPC50 of ciprofloxacin was 128 mg/L, and the MPC50 of levofloxacin was 51.2 mg/L. The MPC50/MIC50 ratio for ciprofloxacin was 64, whereas that for levofloxacin was 25.6. The coefficient of determination between the MPC and MIC for ciprofloxacin and levofloxacin was 0.72 and 0.56, respectively, in the linear regression analysis. Preexisting mutations in GyrA (S83I, S83R, and D87Y) were identified in 18 clinical isolates, all of which were resistant to both ciprofloxacin and levofloxacin. Additional amino acid substitutions in GyrA were identified in all ciprofloxacin- and levofloxacin-selected mutants. Furthermore, GyrB alterations (D431N or D431H) were found in nine levofloxacin-treated isolates. Given that maintaining the serum concentrations of fluoroquinolones above MPCs is impossible under presently recommended doses, the selection of mutant E. anophelis strains seems inevitable.

Extensively drug-resistant Haemophilus influenzae - emergence, epidemiology, risk factors, and regimen.

BACKGROUND: Concern about Haemophilus influenzae infection has been increasing over recent decades. Given the emergence of H. influenzae with severe drug resistance, we assessed the prevalence of as well as risk factors and potential therapies for extensively drug-resistant (XDR) H. influenzae infection in Taiwan. RESULTS: In total, 2091 H. influenzae isolates with disk diffusion-based antibiotic susceptibility testing from 2007 to 2018 were enrolled. H. influenzae strains resistant to ampicillin, chloramphenicol, levofloxacin, and trimethoprim-sulfamethoxazole tended to be isolated from patient wards (≧41%), whereas those resistant to amoxicillin-clavulanate, cefotaxime, and cefuroxime were more likely to be isolated from intensive care units (approximately 50%). XDR H. influenzae was first identified in 2007, and its incidence did not significantly change thereafter. Overall prevalence of single, multiple, and extensively drug-resistant H. influenzae over 2007-2018 was 21.5% (n = 450), 26.6% (n = 557), and 2.5% (n = 52), respectively. A stepwise logistic regression analysis revealed that blood culture (odds ratio: 4.069, 95% confidence intervals: 1.339-12.365, P = 0.013) was an independent risk factor for XDR H. influenzae infection. No nosocomial transmission of XDR H. influenzae observed. Antibiotic susceptibility testing results demonstrated that cefotaxime was effective against 78.8% (n = 41) of the XDR strains. CONCLUSIONS: The presence of XDR H. influenzae strains was identified in Taiwan, and cefotaxime was efficacious against most of these strains.

Serum C-reactive protein and procalcitonin values in acute Q fever, scrub typhus, and murine typhus.

BACKGROUND: Although C-reactive protein (CRP) and procalcitonin (PCT) are widely used inflammatory markers for infectious diseases, their role and potential application for rickettsioses were rarely studied. METHODS: A retrospective chart review and serological study were conducted in patients with rickettsioses. The clinical presentations, characteristics, laboratory data, and treatment responses were recorded and their associations with CRP and PCT values were analyzed. RESULTS: A total of 189 cases of rickettsioses, including 115 cases of acute Q fever (60.8%), 55 cases of scrub typhus (29.1%), and 19 cases of murine typhus (10.1%) were investigated. Both CRP and PCT values increased in the acute phase and declined in the convalescent phase. In the acute phase, mean CRP and PCT values were 78.2 ± 63.7 mg/L and 1.05 ± 1.40 ng/mL, respectively. Percentages of patients falling under different cut-off values of CRP and PCT were calculated systematically. Only 10.8% of CRP was > 150 mg/L and 14.2% of PCT was > 2.0 ng/mL. Patients with delayed responses to doxycycline treatment (> 3 days from treatment to defervescence) had significantly higher CRP values (102.7 ± 77.1 vs. 72.2 ± 58.2 mg/L, p = 0.041) and more PCT > 1.0 ng/ml (48.4% vs. 26.0%, p = 0.019) in the acute phase; higher CRP values (19.1 ± 37.4 vs. 3.6 ± 13.1 mg/L, p = 0.049) and more PCT > 0.5 ng/ml (19.2% vs. 1.4%, p = 0.005) in the convalescent phase. Correlation analysis was conducted for patients with acute Q fever. CRP and PCT values were positively correlated to each other, and both markers also had a positive correlation with serum aspartate transaminase values. Both CRP and PCT values and white blood cell counts were positively correlated to the days needed from doxycycline treatment to defervescence. CONCLUSION: CRP and PCT values might be useful in clinical investigations for patients with suspected rickettsioses and in predicting the response to doxycycline treatment for rickettsioses.

Elizabethkingia bruuniana Infections in Humans, Taiwan, 2005-2017.

Using 16S rRNA and rpoB gene sequencing, we identified 6 patients infected with Elizabethkingia bruuniana treated at E-Da Hospital (Kaohsiung, Taiwan) during 2005-2017. We describe patient characteristics and the molecular characteristics of the E. bruuniana isolates, including their MICs. Larger-scale studies are needed for more robust characterization of this pathogen.

Differences in Clinical Manifestations, Antimicrobial Susceptibility Patterns, and Mutations of Fluoroquinolone Target Genes between Chryseobacterium gleum and Chryseobacterium indologenes.

Chryseobacterium infections are uncommon, and previous studies have revealed that Chryseobacterium gleum is frequently misidentified as Chryseobacterium indologenes We aimed to explore the differences in clinical manifestations and antimicrobial susceptibility patterns between C. gleum and C. indologenes The database of a clinical microbiology laboratory was searched to identify patients with Chryseobacterium infections between 2005 and 2017. Species were reidentified using 16S rRNA gene sequencing, and patients with C. gleum and C. indologenes infections were included in the study. A total of 42 C. gleum and 84 C. indologenes isolates were collected from consecutive patients. A significant increase in C. indologenes incidence was observed. C. gleum was significantly more associated with bacteremia than C. indologenes Patients with C. gleum infections had more comorbidities of malignancy and liver cirrhosis than those with C. indologenes infections. The overall case fatality rate was 19.8%. Independent risk factors for mortality were female sex and C. indologenes infection. These isolates were most susceptible to minocycline (73%), followed by trimethoprim-sulfamethoxazole (47.6%), tigecycline (34.1%), and levofloxacin (32.5%). C. gleum exhibited a significantly higher rate of susceptibility than C. indologenes to piperacillin, piperacillin-tazobactam, ceftazidime, tigecycline, and levofloxacin. Alterations in DNA gyrase subunit A were identified to be associated with fluoroquinolone resistance in C. indologenes No nonsynonymous substitutions were observed in the quinolone resistance-determining regions (QRDRs) of C. gleum Differences in epidemiology, clinical manifestations, and antimicrobial susceptibility patterns exist between C. gleum and C. indologenes Additional investigations are needed to explore the significance of these differences.

Comparison of the Vitek MS and Bruker Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Systems for Identification of Chryseobacterium Isolates from Clinical Specimens and Report of Uncommon Chryseobacterium Infections in Humans.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry is becoming more popular and is replacing traditional identification methods in the clinical microbiology laboratory. We aimed to compare the Vitek mass spectrometry (MS) and Bruker Biotyper systems for the identification of Chryseobacterium isolated from clinical specimens and to report uncommon Chryseobacterium infections in humans. The microbial database from a hospital was searched for records between 2005 and 2016 to identify cultures that yielded Chryseobacterium Species identification by the Vitek MS and Bruker Biotyper systems was compared to identification by 16S rRNA gene sequencing. Over the study period, 140 Chryseobacterium isolates were included. Based on 16S rRNA gene sequencing, 78 isolates were C. indologenes, 39 were C. gleum, 12 were uncommon Chryseobacterium species (C. arthrosphaerae, C. culicis, C. cucumeris, C. bernardetii, C. artocarpi, and C. daecheongense), and the remaining 11 isolates were only identified at the genus level. The Vitek MS and Bruker Biotyper systems correctly identified 98.7% and 100% of C. indologenes isolates, respectively. While the Bruker Biotyper accurately identified 100% of C. gleum isolates, the Vitek MS system correctly identified only 2.6% of isolates from this species. None of the uncommon Chryseobacterium species were successfully identified by either of these two systems. The overall accuracies of Chryseobacterium identification at the species level by the Vitek MS and Bruker Biotyper systems were 60.5% and 90.7%, respectively. An upgrade and correction of the Vitek MS and Bruker Biotyper databases is recommended to correctly identify Chryseobacterium species.

Clinical manifestations, molecular characteristics, antimicrobial susceptibility patterns and contributions of target gene mutation to fluoroquinolone resistance in Elizabethkingia anophelis.

Objectives: Elizabethkingia anophelis has recently emerged as a cause of life-threatening infections in humans. We aimed to investigate the clinical and molecular characteristics of E. anophelis. Methods: A clinical microbiology laboratory database was searched to identify patients with Elizabethkingia infections between 2005 and 2016. Isolates were re-identified and their species were confirmed using 16S rRNA gene sequencing. Patients with E. anophelis infections were included in this study. Clinical information, antimicrobial susceptibility and mutations in DNA gyrase and topoisomerase IV were analysed. Results: A total of 67 patients were identified to have E. anophelis infections, including 47 men and 20 women, with a median age of 61 years. Comorbidity was identified in 85.1% of the patients. Among the 67 E. anophelis isolates, 40 (59.7%) were isolated from blood. The case fatality rate was 28.4%. Inappropriate empirical antimicrobial therapy was an independent risk factor for mortality (adjusted OR = 10.01; 95% CI = 1.20-83.76; P = 0.034). The isolates were 'not susceptible' to multiple antibiotics. All the isolates were susceptible to minocycline. Susceptibilities to ciprofloxacin and levofloxacin were 4.5% and 58.2%, respectively. Mutations in DNA gyrase subunit A were identified in 11 isolates that exhibited high-level fluoroquinolone resistance. Conclusions: Minocycline has the potential to be the drug of choice in patients with E. anophelis infections. Additional investigations are needed to determine the optimal antimicrobial agents to treat this life-threatening infection.

Risk of infection following colonoscopy and sigmoidoscopy in symptomatic patients.

Background and study aims Previous studies describing the incidence of infection after colonoscopy and sigmoidoscopy are limited. The aim of this study was to determine the incidence of infection, and to propose a nomogram to predict the probability of infection following colonoscopy and sigmoidoscopy in symptomatic patients. Patients and methods A nationwide retrospective study was conducted by analyzing the National Health Insurance Research Database of Taiwan. The incidence of infection within 30 days after colonoscopy and sigmoidoscopy was assessed and compared with a control group matched at a ratio of 1:1 based on age, sex, and the date of examination. Results In all, 112 543 patients who underwent colonoscopy or sigmoidoscopy and 112 543 matched patients who did not undergo these procedures were included. The overall incidence of infection within 30 days after colonoscopy and sigmoidoscopy was 0.37 %, which was significantly higher than that of the control group (0.04 %; P < 0.001). Diverticulitis, peritonitis, and appendicitis were the most common infections. Patients who underwent colonoscopy or sigmoidoscopy had a 9.38-fold risk of infection (95 % confidence interval, 6.81 - 12.93; P < 0.001) compared with the control group. The predicted infection-free rates of the nomogram were closely aligned with the actual infection-free rates, with a bootstrapping concordance index of 0.763. Conclusions Colonoscopy and sigmoidoscopy are associated with an increased risk of infection, which may occur after these procedures. Our nomogram may provide clinicians with an easy tool to evaluate the risk of infection after colonoscopy and sigmoidoscopy in symptomatic patients.

Changing hepatitis D virus epidemiology in a hepatitis B virus endemic area with a national vaccination program.

UNLABELLED: The emergence of hepatitis D virus (HDV) infection in the era of widespread HBV vaccination has not been described before. We aimed to investigate the changing epidemiology of HDV infection among high- and low-risk populations after an outbreak of human immunodeficiency virus (HIV) infection among injection drug users (IDUs) in Taiwan. A prospective, multicenter, cohort study of 2,562 hepatitis B surface antigen (HBsAg)-positive individuals was conducted to determine the prevalence, genotype, and risk factors of HDV infection from 2001 through 2012. The prevalence rates of HDV infection were 74.9%, 43.9%, 11.4%, 11.1%, and 4.4% among HIV-infected IDUs, HIV-uninfected IDUs, HIV-infected men who have sex with men, HIV-infected heterosexuals, and the general population of HBsAg-positive subjects, respectively. A significant increase in the trend of HDV prevalence from 38.5% to 89.8% was observed in HIV-infected IDUs (odds ratio = 3.06; 95% confidence interval: 1.68-5.56; P = 0.0002). In multivariate analysis, injection drug use, hepatitis C virus infection, HIV infection, serum HBsAg level ≧250 IU/mL, duration of drug use, and older age were significant factors associated with HDV infection. HDV genotype IV (72.2%) was the prevalent genotype circulating among IDUs, whereas genotype II was predominant in the non-IDU populations (73.3%). In the HIV cohort born after 1987 who were HBsAg negative, over half (52.9%) had antibody to hepatitis B surface antigen antibody levels of <10 mIU/mL and there was a significantly higher HBsAg seroprevalence in the HIV cohort, compared to the control group (8.1% vs. 0.0%; P = 0.02). CONCLUSION: In the era of HBV vaccination, IDUs and HIV-infected individuals have emerged as high-risk groups and a reservoir for HDV infection. Effective strategies are needed to curb the reemerging epidemic of HDV infection in these high-risk groups.

Pyogenic liver abscess in patients with inflammatory bowel disease: a nationwide cohort study.

BACKGROUND & AIMS: Pyogenic liver abscess (PLA) is a rare and severe extraintestinal complication in patients with inflammatory bowel disease (IBD). However, the incidence of PLA in patients with IBD remains unknown. METHODS: A nationwide cohort study was conducted by analysing data from the National Health Insurance Research Database in Taiwan. Patients with IBD (N = 11 504) from 2000 to 2010 and control participants without IBD (N = 46 016) were included in this study. We analysed the risks of PLA by using competing-risks (death) regression models. RESULTS: The incidence of PLA was higher in the IBD cohort than in the control cohort (6.72 vs 4.06 per 10 000 person-years), with an adjusted subhazard ratio (SHR) of 1.46 (95% confidence interval [CI], 1.01-2.12). Patients with IBD who required two or more hospitalizations per year and underwent laparotomy had an increased risk of PLA. Patients with ulcerative colitis were more likely to develop PLA than were those with Crohn's disease (incidence, 8.56 vs 5.45 per 10 000 person-years; adjusted SHR, 1.65 vs 1.32). Among the IBD cohort, age and gender did not affect PLA risk. Patients with diabetes mellitus or percutaneous aspiration of the gallbladder and biliary tract and who underwent endoscopic insertion of a biliary drainage tube exhibited a significantly increased risk of PLA. CONCLUSIONS: Patients with IBD exhibited an increased risk of developing PLA, particularly those with ulcerative colitis. Knowledge of the expected frequency and potential risk for this severe extraintestinal infection may minimize the serious consequences.

Risk of leukaemia in children infected with enterovirus: a nationwide, retrospective, population-based, Taiwanese-registry, cohort study.

BACKGROUND: The association between enterovirus infections in children and risk of leukaemia is unclear. We aimed to assess the risk of leukaemia after enterovirus infection in children. METHODS: We did a nationwide retrospective cohort study by analysing data from the National Health Insurance Research Database (NHIRD) in Taiwan. Children with enterovirus infections aged younger than 18 years were identified. With use of computer-generated random numbers, children not infected with enterovirus were randomly selected and frequency matched (1:1) with children infected with enterovirus by sex, age, urbanisation level, parental occupation, and index year of enterovirus infection. We only included children with complete baseline data for age and sex and who had at least three clinic visits with the diagnosis of enterovirus infection. The diagnosis date of the first clinic visit for the enterovirus infection was defined as the index date for initiation of follow-up person-year measurement and participants. All study patients were followed up until they developed leukaemia, were lost to follow-up, withdrew from the NHI programme, or until the end of the study without leukaemia (censored). Our primary endpoint was a diagnosis of leukaemia during follow-up. FINDINGS: Insurance claims data for 3 054 336 children younger than 18 years were randomly selected from all insured children in the NHIRD. We identified 282 360 children infected with enterovirus and 282 355 children not infected with enterovirus between Jan 1, 2000, and Dec 31, 2007. The incidence density rates of leukaemia were 3·26 per 100 000 person-years for the enterovirus-infected and 5·84 per 100 000 person-years for the non-enterovirus-infected cohorts. The risk of leukaemia was significantly lower in the enterovirus-infected cohort than in the non-enterovirus-infected cohort (adjusted subhazard ratio [SHR] 0·44, 95% CI 0·31-0·60; p<0·0001). Children infected with enterovirus have a reduced risk of both lymphocytic leukaemia (adjusted SHR 0·44, 0·30-0·65; p<0·0001) and acute myeloid leukaemia (adjusted SHR 0·40, 0·17-0·97; p=0·04). Herpangina and hand-foot-and-mouth disease were the main diseases associated with the reduced risk of leukaemia. INTERPRETATION: The association between enterovirus infection and the reduced risk of developing leukaemia supports Greaves' delayed infection hypothesis for the cause of childhood leukaemia.

Association of Human Q Fever with Animal Husbandry, Taiwan, 2004-2012.

In Taiwan, Q fever cases in humans began increasing in 2004 and peaked in 2007 but dramatically declined in 2008 and 2011. Cases were significantly correlated with the number of goats. The decline might be associated with the collateral effects of measures to control goat pox in 2008 and 2010.

The role of Sequence Type (ST) 131 in adult community-onset non-ESBL-producing Escherichia coli bacteraemia.

BACKGROUND: To compare the epidemiological and clinical features and outcome in clonal group O25b/ST131 and non-clonal group O25b/ST131 in adult patients with non-extended-spectrum B-lactamase (ESBL)-producing Escherichia coli (E. coli) bacteraemia. METHODS: We collected 371 consecutive isolates with community-onset non-ESBL producing E. coli bloodstream infection in 2010 in a 1200-bed hospital in Taiwan. Twenty adult patients with clonal group O25b/ST131 and 40 patients with non-clonal group O25b/ST131 were compared. RESULT: Clonal group O25b/ST131 accounted for 5.9% of total isolates. The underlying disease and healthcare-associated risk factors were similar in the case and control groups. Patients with the clonal group O25b/ST131 were less likely to have intra-abdominal infection (0% vs. 22.5%; p < 0.05) than patients from the control group. The Day 30 mortality rate was similar in the case and control groups (15% vs. 12.5%). CONCLUSIONS: Clonal group O25b/ST131 was found in both multidrug-resistant and susceptible E. coli strains, causing community-onset bloodstream infection. Although O25b/ST131 does not lead to a higher mortality than other isolates, choosing an appropriate antimicrobials in the empirical therapy of community-onset E. coli bacteraemia has become more challenging.

The first imported human case of Yersinia pseudotuberculosis serotype O1 septicemia presents with acute appendicitis-like syndrome in Taiwan.

Human nonplague yersiniosis occurs more commonly in temperate regions than in tropical or subtropical regions. In Taiwan, which is located in a subtropical region of Southeast Asia, only environmental isolates and human infection of Yersinia enterocolitica were reported, but a human case of Y. pseudotuberculosis infection had not been identified. We report the first person with Y. pseudotuberculosis serotype O1 septicemia who presented with acute appendicitis-like syndrome and who was probably contracted the infection via ingestion of raw foods in a barbecue restaurant in Japan.

Risk Factors and Outcomes of Community-Acquired Carbapenem-Resistant Klebsiella pneumoniae Infection in Elderly Patients.

The increasing prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections is a global concern. Elderly patients have a diminished immune response and functional reserve, and are thus more vulnerable to bacterial infection. This study aimed to investigate the risk factors and outcomes in elderly patients with community-acquired CRKP infections. We performed a retrospective cohort study in a tertiary medical center between 1 January 2021, and 31 December 2021. All elderly patients who visited the emergency department during this period with culture-positive K. pneumoniae were enrolled, and their baseline demographics, laboratory profiles, management strategies, and outcomes were recorded and analyzed. We identified 528 elderly patients with K. pneumonia infection, and the proportion of patients with CRKP infection was 10.2% (54/528). Recent intensive care unit (ICU) admission and prior carbapenem use are independent risk factors for CRKP infection in elderly patients. Compared to patients with carbapenem-sensitive K. pneumoniae infection, those with CRKP infection had a significantly higher risk of adverse outcomes, including ICU care, respiratory failure, septic shock, and 90-day mortality. CRKP infection was also identified as an independent risk factor for 90-day mortality. Clinicians should be aware of the increasing prevalence of CRKP infections in elderly patients and judiciously choose appropriate antibiotics for these patients.

In vitro induction and selection of fluoroquinolone-resistant mutants in Elizabethkingia anophelis.

For 29 parent strains, recognized by pulsed-field gel electrophoresis, the MICs multiplied significantly in the ciprofloxacin group than levofloxacin group, following the first and third induction cycle. Ser83Arg in GyrA was the most common site of mutations. No mutation in ParC nor ParE was identified in the selected mutants.

Characterization of CRISPR-Cas Systems in Shewanella algae and Shewanella haliotis: Insights into the Adaptation and Survival of Marine Pathogens.

CRISPR-Cas systems are adaptive immune mechanisms present in most prokaryotes that play an important role in the adaptation of bacteria and archaea to new environments. Shewanella algae is a marine zoonotic pathogen with worldwide distribution, which accounts for the majority of clinical cases of Shewanella infections. However, the characterization of Shewanella algae CRISPR-Cas systems has not been well investigated yet. Through whole genome sequence analysis, we characterized the CRISPR-Cas systems in S. algae. Our results indicate that CRISPR-Cas systems are prevalent in S. algae, with the majority of strains containing the Type I-F system. This study provides new insights into the diversity and function of CRISPR-Cas systems in S. algae and highlights their potential role in the adaptation and survival of these marine pathogens.