Impact of biofilm production by Candida species and antifungal therapy on mortality of patients with candidemia.

BACKGROUND AND OBJECTIVES: Few studies have investigated the clinical outcomes of patients with candidemia caused by Candida species with different levels of biofilm formation. We aimed to investigate the impact of antifungal therapy on the outcome of candidemia caused by Candida species that were categorised as low biofilm formers (LBFs), moderate biofilm formers (MBFs), and high biofilm formers (HBFs). METHODS: Adults with candidemia caused by LBF and HBF/MBF Candida species that were susceptible to fluconazole and caspofungin were included to investigate the impact of treatment with fluconazole vs an echinocandin on 30-day crude mortality. RESULTS: In total, 215 patients with candidemia received fluconazole and 116 patients received an echinocandin. In multivariate analysis, Pittsburgh bacteremia score ≥ 4 (adjusted odds ratio [AOR] =2.42; 95% confidence interval [CI], 1.32-4.41), malignancy (AOR = 3.45; 95% CI, 1.83-6.51), not removing the central venous catheter within 48 hours of a positive blood culture (AOR = 4.69; 95% CI, 2.61-8.45), and treatment with fluconazole for candidemia due to HBF/MBF Candida spp. (AOR = 2.23; 95% CI, 1.22-4.06) were independent factors associated with 30-day mortality. Of the 165 patients infected by HBF/MBF Candida isolates, those who received azole therapy had a significantly higher sepsis-related mortality rate than those who received echinocandin therapy (44.9% [49/109] vs 26.8% [15/56], P = .03). CONCLUSIONS: There was a trend of an independent association between fluconazole treatment and poor outcomes in the patients infected by HBF/MBF Candida strains.

Treatment of pulmonary disease caused by Mycobacterium kansasii.

As a cause of lung disease (LD), Mycobacterium kansasii is regarded as a highly virulent species among nontuberculous mycobacteria (NTM). Both the frequency of M. kansasii isolates and global prevalence of M. kansasii-LD have increased gradually over recent decades. Treatment of M. kansasii-LD is recommended because of the disease's poor prognosis and fatal outcome. The decision on the optimal time point for treatment initiation should be based on both the benefits and risks posed by multiple antimicrobial agents. For treatment-naïve patients with M. kansasii-LD, rifampin-containing multiple antimicrobial regimens for ≥12 months after culture negative conversion are effective. However, some challenges remain, such as determining the precise length of treatment duration as well as addressing intolerable adverse effects, the uncertain effectiveness of isoniazid and ethambutol in treatment, the uncertain correlation between in vitro drug susceptibility testing and clinical outcomes, and the increasing prevalence of clarithromycin-resistant M. kansasii isolates. Short-course and effective therapies must be developed. New candidate drugs, such as tedizoid and clofazimine, exhibit excellent antimycobacterial activity against M. kansasii in vitro, but in vivo studies of their clinical applications are lacking. This paper reviews the treatment, outcomes and future directions in patients with M. kansasii-LD.

Toona sinensis modulates autophagy and cytokines in lipopolysaccharide-induced RAW 264.7 macrophages.

Toona sinensis (TS) is a medicinal herb possessing anti-apoptotic, anti-oxidant, and anti-inflammatory properties and is used to treat diabetes, cancer, and inflammatory diseases. In traditional Chinese medicine theory, TS clears dampness and heat, strengthens the stomach function, and regulates vital energy flow. TS is also used as an astringent and a pesticide. In this study, we aimed to evaluate how TS influences autophagy and cytokines during the inflammatory process in RAW 264.7 macrophages. The treatment groups were pre-supplemented with TS leaf extract; rapamycin was used to enhance autophagy and lipopolysaccharide (LPS) was used to induce inflammation. The expression of autophagy-related proteins was analyzed by western blotting. The survival rate of, and chemokine expression and oxidative stress in the cells were also assessed. TS leaf extract inhibited mammalian target of rapamycin (mTOR) phosphorylation at site S2448 in the macrophages. At relatively higher concentrations (50 and 75 µg/mL), TS elevated the expression of light chain 3 II (LC3-II), which further modulated autophagy. Pre-supplementation with TS leaf extract elevated the total glutathione (GSH) level and GSH/oxidized GSH (GSSG) ratio, but it decreased the GSSG, total nitric oxide, nitrate, nitrite, malondialdehyde, and superoxide anion levels. TS reversed the effects of LPS-induced cytokines, including interleukin (IL)-6 and IL-10. TS did not induce significant toxicity at the studied concentrations. In conclusion, TS leaf extract may modulate autophagy during inflammation. Furthermore, it may prevent cell damage via anti-inflammation and anti-oxidation. Thus, this study supports the ethnomedical use of TS in the prevention of inflammation-related diseases.

A 14 day esomeprazole- and amoxicillin-containing high-dose dual therapy regimen achieves a high eradication rate as first-line anti-Helicobacter pylori treatment in Taiwan: a prospective randomized trial.

BACKGROUND: The first-line eradication rate of standard triple therapy for Helicobacter pylori infection has declined to <80%, and alternative therapies with >90% success rates are needed. Inconsistent eradication rates were reported for proton pump inhibitor- and amoxicillin-containing high-dose dual therapy. OBJECTIVES: We performed a prospective, randomized controlled study to assess the efficacy of esomeprazole- and amoxicillin-containing high-dose dual therapy and investigated the influencing clinical factors. PATIENTS AND METHODS: We recruited 240/278 eligible H. pylori-infected patients after exclusion. They were randomly assigned to 14 day high-dose dual therapy (esomeprazole 40 mg three times daily and amoxicillin 750 mg four times daily for 14 days; EA group) or 7 day non-bismuth quadruple therapy (esomeprazole 40 mg twice daily, clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily and metronidazole 500 mg twice daily for 7 days; EACM group). Urea breath tests were followed up 8 weeks later. RESULTS: The eradication rates for the EA and EACM groups were 91.7% (95% CI = 85.3%-96.0%) and 86.7% (95% CI = 79.3%-92.2%) (P = 0.21) in ITT analysis; and 95.7% (95% CI = 90.2%-98.6%) and 92.0% (95% CI = 85.4%-96.3%) (P = 0.26) in PP analysis. The adverse event rates were 9.6% versus 23.0% in the two groups (P = 0.01). The H. pylori culture positivity rate was 91.8%. The antibiotic resistance rates were amoxicillin, 0%; clarithromycin, 14.6%; and metronidazole, 33.7%. CONCLUSIONS: A 14 day esomeprazole- and amoxicillin-containing high-dose dual therapy achieves a high eradication rate as first-line anti-H. pylori therapy, comparable to that with 7 day non-bismuth quadruple therapy but with fewer adverse events.

Five-year sequential changes in secondary antibiotic resistance of Helicobacter pylori in Taiwan.

AIM: To determine changes in the antibiotic resistance of Helicobacter pylori (H. pylori) in southern Taiwan after failure of first-line standard triple therapy. METHODS: We analyzed 137 H. pylori-infected isolates from patients who experienced eradication failure after standard first-line triple therapy from January 2010 to December 2014. The H. pylori strains were tested for susceptibility to amoxicillin, clarithromycin, levofloxacin, metronidazole and tetracycline using the E-test method. The minimal inhibitory concentration (MIC) was determined by the agar dilution test. MIC values of ≥ 0.5, ≥ 1, ≥ 1, ≥ 4 and ≥ 8 mg/L were considered to be the resistance breakpoints for amoxicillin, clarithromycin, levofloxacin, tetracycline and metronidazole, respectively. RESULTS: A high resistance rate was found for clarithromycin (65%-75%) and metronidazole (30%-40%) among patients who failed first-line standard therapy. The resistance levels to amoxicillin and tetracycline remained very low; however, levofloxacin resistance was as high as 37.5% in 2010 but did not increase any further during the past 5 years. The rates of resistance to these antibiotics did not show a statistically significant upward or downward trend. CONCLUSION: Antibiotic resistance of H. pylori remains a problem for the effective eradication of this pathogen and its associated diseases in Taiwan. High clarithromycin resistance indicated that this antibiotic should not be prescribed as a second-line H. pylori eradication therapy. Moreover, levofloxacin-based second-line therapy should be used cautiously, and the local resistance rates should be carefully monitored.

Comparative effectiveness of flomoxef versus carbapenems in the treatment of bacteraemia due to extended-spectrum ß-lactamase-producing Escherichia coli or Klebsiella pneumoniae with emphasis on minimum inhibitory concentration of flomoxef: a retrospective study.

This study compared treatment outcomes of adult patients with bacteraemia due to extended-spectrum ß-lactamase-producing Escherichia coli or Klebsiella pneumoniae (ESBL-EK) receiving flomoxef versus those receiving a carbapenem as definitive therapy. In propensity score matching (PSM) analysis, case patients receiving flomoxef shown to be active in vitro against ESBL-EK were matched with controls who received a carbapenem. The primary endpoint was 30-day crude mortality. The flomoxef group had statistically significantly higher sepsis-related mortality (27.3% vs. 10.5%) and 30-day mortality (28.8% vs. 12.8%) than the carbapenem group. Of the bacteraemic episodes caused by isolates with a MICflomoxef of ≤1 mg/L, sepsis-related mortality rates were similar between the two treatment groups (8.7% vs. 6.4%; P=0.73). The sepsis-related mortality rate of the flomoxef group increased to 29.6% and 50.0% of episodes caused by isolates with a MICflomoxef of 2-4 mg/L and 8 mg/L, respectively, which was significantly higher than the carbapenem group (12.3%). In the PSM analysis of 86 case-control pairs infected with strains with a MICflomoxef of 2-8 mg/L, case patients had a significantly higher 30-day mortality rate (38.4% vs. 18.6%). Multivariate regression analysis revealed that flomoxef therapy for isolates with a MICflomoxef of 2-8 mg/L, concurrent pneumonia or urosepsis, and a Pitt bacteraemia score ≥4 were independently associated with 30-day mortality. Definitive flomoxef therapy appears to be inferior to carbapenems in treating ESBL-EK bacteraemia, particularly for isolates with a MICflomoxef of 2-8 mg/L, even though the currently suggested MIC breakpoint of flomoxef is ≤8 mg/L.

Refractory vertebral osteomyelitis due to CTX-M-14-producing Escherichia coli at ertapenem treatment in a patient with a coexisting urinary tract infection caused by the same pathogen.

We report the case of a patient with vertebral osteomyelitis and concurrent urinary tract infection (UTI) in which extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (EC(1)) isolated from urine culture was ciprofloxacin-resistant and ertapenem/imipenem-susceptible. The empirically used oral form of ciprofloxacin was switched to parenteral ertapenem based on the antimicrobial susceptibility. However, vertebral osteomyelitis deteriorated, and despite the disappearance of pyuria and a negative urine culture, ESBL-producing E. coli was isolated from a biopsy of the bony material from the fifth lumbar vertebra (EC(2)) and blood culture (EC(3)) at 10 and 12 days after starting ertapenem, respectively. Ertapenem was switched to imipenem, and defervescence occurred 2 days later; a subsequent blood culture was negative. Genotyping indicated that EC(1), EC(2), and EC(3) were of the same clone, with the ESBL being CTX-M-14. The tested antibiotics had identical minimum inhibitory concentrations against each of these isolates. From the pharmacokinetics/pharmacodynamics points of view, it is reasonable to attribute the ertapenem treatment failure in vertebral osteomyelitis due to ESBL-producing E. coli in this case to the suboptimal ertapenem concentration in the inflammatory bone tissue of the host.

Antimicrobial effects of varied combinations of meropenem, sulbactam, and colistin on a multidrug-resistant Acinetobacter baumannii isolate that caused meningitis and bacteremia.

Meropenem (MEM; 2 g/8 hr; minimum inhibitory concentration [MIC] = 256 mg/L) plus sulbactam (SUL; 1 g/8 hr; MIC = 128 mg/L) (two-drug-therapy period), and subsequent additional intravenous colistin (COL; 2.5 mg/kg/12 hr) and intraventricular (COL, 5 mg/day; MIC = 1 mg/L) (three-drug-therapy period) were sequentially used in a patient with postneurosurgery bacteremic meningitis due to a multidrug-resistant Acinetobacter baumannii (MDRAB) isolate (AB(1)). We detected 4- to 32-fold increases in peak or trough cerebrospinal fluid bactericidal titer and serum bactericidal titer in three-drug-therapy period when comparing to those in two-drug-therapy period. The time-kill study with MEM, SUL, and COL alone or varied combinations (all at 1 x MIC) against AB(1) and another genetically nonrelated MDRAB isolate (AB(134) [MICs of MEM = 64 mg/L, SUL = 16 mg/L, and COL = 1 mg/L]) was performed. The two-drug combinations (MEM + SUL, MEM + COL, and SUL + COL) each elicited different inhibitory effect on AB(1) and AB(134) at 6 hr. Bacterial regrowth at 24 hr was observed in the experiments in which the MDRAB isolate was inhibited earlier by COL alone (AB(1) and AB(134)), by MEM plus SUL (AB(1)), and by MEM plus COL (AB(134)), but not in SUL plus COL, and MEM + SUL + COL. Combined use of COL with MEM and/or SUL may provide good therapeutic options, even though MEM and SUL are in vitro resistance to the MDRAB.

Collateral damage of flomoxef therapy: in vivo development of porin deficiency and acquisition of blaDHA-1 leading to ertapenem resistance in a clinical isolate of Klebsiella pneumoniae producing CTX-M-3 and SHV-5 beta-lactamases.

OBJECTIVES: The study aimed to characterize the genetic basis of flomoxef and collateral ertapenem resistance in a clinical isolate of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) after flomoxef exposure. METHODS: Four ESBL-KP isolates (Lkp11-14) were recovered sequentially from four episodes of bacteraemia in an elderly patient. Laboratory investigations included genotyping by PFGE, resistance gene analysis by PCR and sequencing, and outer membrane protein analysis by SDS-PAGE. Plasmid analysis by DNA-DNA hybridization, electroporation and conjugation was also performed. RESULTS: Lkp14 was recovered after 21 days of flomoxef therapy. It demonstrated an indistinguishable PFGE pattern when compared with those produced by Lkp11-13. However, resistance to both flomoxef and ertapenem emerged in Lkp14. Molecular characterization revealed that, in addition to the pre-existing ESBL production (CTX-M-3 and SHV-5) and OmpK35 deficiency found in Lkp11-13, Lkp14 had acquired an extra plasmid-mediated AmpC beta-lactamase gene (blaDHA-1) and failed to express OmpK36, because of insertional inactivation by an insertion sequence IS5. Other resistance mechanisms, such as production of carbapenem-hydrolysing enzymes or expression of chromosomal efflux, were apparently not involved. Conjugational transfer of the plasmid-mediated blaDHA-1 gene into Lkp11 resulted in a significant increase in the MICs of cephamycins and beta-lactamase inhibitors, but not in those of carbapenems. CONCLUSIONS: Lkp14 was apparently derived from the previously flomoxef-susceptible isolates, Lkp11-13. After flomoxef exposure, the in vivo acquisition of the plasmid-mediated blaDHA-1 gene has led to flomoxef resistance in Lkp14, and the concomitant depletion of OmpK36 expression has resulted in a collateral effect of ertapenem resistance and diminished susceptibilities to imipenem and meropenem.

Treatment of ESBL-producing Klebsiella pneumoniae bacteraemia with carbapenems or flomoxef: a retrospective study and laboratory analysis of the isolates.

OBJECTIVES: To better understand the clinical outcomes of patients with extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) bacteraemia treated with either flomoxef or a carbapenem, and to evaluate the in vitro activities of these antibiotics against ESBL-KP. METHODS: Retrospective analyses to identify risk factors for mortality in patients with flomoxef-susceptible ESBL-KP, especially addressing the therapeutic roles of flomoxef and carbapenem. In vitro activities of flomoxef and carbapenem against flomoxef-susceptible ESBL-KP isolates were evaluated by susceptibility testing and time-kill study. RESULTS: Twenty-seven patients (flomoxef group, n=7; carbapenem group, n=20) were included. Clinical severity reflected by high Pitt bacteraemia score (>or=6) was an independent risk factor for mortality (OR 13.43; 95% CI, 1.08-166.73; P=0.043), while use of flomoxef or a carbapenem was not. The MICs of flomoxef and carbapenem indicated that the tested ESBL-KP were susceptible to these antibiotics regardless of the inoculum size of 10(5) or 10(7) cfu/mL. Time-kill study showed that these antibiotics (flomoxef 8 mg/L and meropenem 4 mg/L) each acted actively against and inhibited the regrowth of the tested ESBL-KP for at least 24 h. CONCLUSIONS: Flomoxef might be as clinically effective as a carbapenem in treating flomoxef-susceptible ESBL-KP bacteraemia.

In vivo selection of OmpK35-deficient mutant after cefuroxime therapy for primary liver abscess caused by Klebsiella pneumoniae.

OBJECTIVES: The aim of the study was to characterize the genetic basis of beta-lactam resistance developed in clinical isolates of Klebsiella pneumoniae after exposure to cefuroxime. METHODS: Clinical features of two episodes of liver abscess caused by K. pneumoniae in a diabetic patient were reported. Four isolates (KP(1)/KP(2) and KP(3)/KP(4)) of K. pneumoniae were recovered from cultures of blood/pus in the first and second episodes, respectively. Laboratory investigation of the K. pneumoniae isolates included genotyping by PFGE, resistance gene analysis by PCR amplification and DNA sequencing, and outer membrane protein analysis by SDS-PAGE. RESULTS: KP(3) and KP(4) were recovered after a 21 day cefuroxime therapy and demonstrated identical genotypes to that of KP(1) and KP(2). However, compared with KP(1) and KP(2), emerging resistance to piperacillin, cefalotin, cefuroxime and cefoxitin was observed. The other antibiotics tested, except ampicillin, retained the same effectiveness against the four isolates, although increases (4- to 8-fold) in the MICs of cefotaxime, ceftriaxone, ceftazidime, cefepime, flomoxef and aztreonam were observed in KP(3) and KP(4). None of the isolates produced extended-spectrum beta-lactamases or plasmid-mediated AmpC beta-lactamases. Deficiency in the expression of an outer membrane protein (OmpK35) was observed in the cefuroxime-resistant isolates, KP(3) and KP(4). CONCLUSIONS: The increased resistance to cephalosporins in these clinical isolates of K. pneumoniae after exposure to cefuroxime might be related to the loss of OmpK35.