infections are uncommon, and previous studies have revealed that
is frequently misidentified as
We aimed to explore the differences in clinical manifestations and antimicrobial susceptibility ...patterns between
and
The database of a clinical microbiology laboratory was searched to identify patients with
infections between 2005 and 2017. Species were reidentified using 16S rRNA gene sequencing, and patients with
and
infections were included in the study. A total of 42
and 84
isolates were collected from consecutive patients. A significant increase in
incidence was observed.
was significantly more associated with bacteremia than
Patients with
infections had more comorbidities of malignancy and liver cirrhosis than those with
infections. The overall case fatality rate was 19.8%. Independent risk factors for mortality were female sex and
infection. These isolates were most susceptible to minocycline (73%), followed by trimethoprim-sulfamethoxazole (47.6%), tigecycline (34.1%), and levofloxacin (32.5%).
exhibited a significantly higher rate of susceptibility than
to piperacillin, piperacillin-tazobactam, ceftazidime, tigecycline, and levofloxacin. Alterations in DNA gyrase subunit A were identified to be associated with fluoroquinolone resistance in
No nonsynonymous substitutions were observed in the quinolone resistance-determining regions (QRDRs) of
Differences in epidemiology, clinical manifestations, and antimicrobial susceptibility patterns exist between
and
Additional investigations are needed to explore the significance of these differences.
Background
Scrub typhus (ST) is one of the most underdiagnosed, potentially fatal febrile diseases in the Asia‐Pacific region. We conducted a comprehensive review of the risk factors of ST over ...19 years using data from a nationwide database.
Methods
We used data on ST from the nationwide database of the Taiwan Centers for Disease Control from 1996 to 2014 to analyse the incidence rates and relative risks of ST according to different regions. The trends of incidence rates over the study period were also evaluated. The distribution of confirmed ST cases was mapped using geographic information system software. The characteristics of confirmed ST cases and non‐ST cases (cases with suspected ST but negative test findings) were compared.
Results
Among the 38,127 reported cases, there were 6,791 (17.8%) confirmed ST cases. The overall incidence rate of ST in Taiwan was 1.49 per 100,000 residents per year. The trend of incidence rates increased over time. The Island region had the highest incidence rate (56.55 per 100,000 residents per year), followed by the Eastern region (15.13 per 100,000 residents per year). More confirmed ST cases were distributed in mountainous areas of Taiwan Main Island and Island region. Compared to non‐ST cases, individuals with confirmed ST were younger (median interquartile range age: 44 26–57 years versus 45 30–60 years, p < .001) and more likely to engage in at‐risk occupations (29.4% versus 13.3%, p < .001), including farming and animal husbandry (16.6% versus 9.0%, p < .001) and the armed forces (12.3% versus 3.5%, p < .001); however, they had a lower rate of animal contact (12.8% versus 20.1%, p < .001).
Conclusions
ST is an endemic disease in Taiwan, particularly in the Island region, Eastern region and mountainous areas. Patients engaged in at‐risk occupations and presenting with acute febrile diseases should undergo investigations for ST.
has emerged as a critical human pathogen, and a number of isolated reports have described the successful treatment of
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
. The minimum inhibitory concentration ranges of vancomycin and rifampin against 167 isolates of
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
infections.
Fluoroquinolones are potentially active against
. 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
. 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
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
= 0.04). Overall, no mutations were discovered in
and
throughout the multicycles inducted by levofloxacin and all its combinations. Regarding the vastly increased MICs, the second point mutations in
and/or
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
and/or
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
mutants with high MICs after levofloxacin exposure could be effectively delayed or postponed by antimicrobial combination with other in vitro active antibiotics.
The genus
has recently emerged as a cause of life-threatening infections in humans, particularly in immunocompromised patients. Several new species in the genus
have been proposed in the last decade. ...Numerous studies have indicated that
, rather than
, is the most prevalent pathogen in this genus. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry systems with an extended spectrum database could reliably identify
and
, but they are unable to distinguish the remaining species. Precise species identification relies on molecular techniques, such as housekeeping gene sequencing and whole-genome sequencing. These microorganisms are usually susceptible to minocycline but resistant to most β-lactams, β-lactam/β-lactam inhibitors, carbapenems, and aminoglycosides. They often exhibit variable susceptibility to piperacillin, piperacillin-tazobactam, fluoroquinolones, and trimethoprim-sulfamethoxazole. Accordingly, treatment should be guided by antimicrobial susceptibility testing. Target gene mutations are markedly associated with fluoroquinolone resistance. Knowledge on the genomic characteristics provides valuable insights into in these emerging pathogens.
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.
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.
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.
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.
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 β-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.
Summary 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. Funding Taiwan Ministry of Health and Welfare, Academia Sinica, NRPB Stroke Clinical Trial Consortium, Tseng-Lien Lin Foundation, Taiwan Brain Disease Foundation, Katsuzo and Kiyo Aoshima Memorial Funds, China Medical University Hospital, and Taiwan Ministry of Education.
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. (Hepatology 2015;61:1870–1879)
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