Levofloxacin-induced MexS mutation triggers imipenem-relebactam resistance in a KPC-producing Pseudomonas aeruginosa.

OBJECTIVES: Imipenem-relebactam (IMR), a novel ß-lactam/ß-lactamase inhibitor combination, is recommended for infections caused by difficult-to-treat Pseudomonas aeruginosa. This study aimed to investigate the evolution trajectory of IMR resistance under the selection of levofloxacin in P. aeruginosa. METHODS: Antimicrobial susceptibility testing, complete genome sequencing and gene manipulation experiments were performed. Quantitative reverse transcription PCR for specific genes and porin levels were detected. Evolution trajectory was simulated in vitro by induction assay. RESULTS: P. aeruginosa HS347 and HS355 were isolated from abdominal drainage of two neighbouring patients (S and Z) undergoing surgery of colon carcinoma in Shanghai, China, with the latter patient having received levofloxacin. They were closely related ST16 strains, and both carried blaKPC-2 plasmids highly similar to those of P. aeruginosa endemic clones from Zhejiang province, where patient Z had received enteroscopy before this admission. Acquisition of resistance was observed for both IMR and fluoroquinolones in HS355, likely prompted by treatment with levofloxacin. The T274I substitution in MexS (putative oxidoreductase), upregulated efflux pump operon mexEF-oprN and decreased production of porin OprD leading to cross-resistance to fluoroquinolones and IMR, which was also verified by in vitro mutant selection under levofloxacin selection. CONCLUSIONS: The emergence of a rare blaKPC-2-plasmid-bearing ST16 clone implies the horizonal spread and inter-regional dissemination of a high-risk plasmid-clone combination, representing a public health challenge. Levofloxacin exposure can select for mexS inactivating mutation, which in turn leads to IMR resistance phenotype, implicating the role of an unrelated, widely used antimicrobial agent in insidiously triggering the development of cross resistance to a latest ß-lactam/ß-lactamase inhibitor combination.

Physicians' knowledge of invasive fungal disease in China.

BACKGROUND: Invasive fungal disease (IFD) is associated with high morbidity and mortality. Data are lacking regarding physicians' perspectives on the diagnosis and management of IFD in China. OBJECTIVES: To evaluate physicians' perspectives on the diagnosis and management of IFD. METHODS: Based on current guidelines, a questionnaire was designed and administered to 294 physicians working in haematology departments, intensive care units, respiratory departments and infectious diseases departments in 18 hospitals in China. RESULTS: The total score and subsection scores for invasive candidiasis, invasive aspergillosis (IA), cryptococcosis and invasive mucormycosis (IM) were 72.0 ± 12.2 (maximum = 100), 11.1 ± 2.7 (maximum = 19), 43.0 ± 7.8 (maximum = 57), 8.1 ± 2.0 (maximum = 11) and 9.8 ± 2.3 (maximum = 13), respectively. Although the perspectives of the Chinese physicians were in good overall agreement with guideline recommendations, some knowledge gaps were identified. Specific areas in which the physicians' perspectives and guideline recommendations differed included use of the ß-D-glucan test to facilitate the diagnosis of IFD, relative utility of the serum galactomannan test and bronchoalveolar lavage fluid galactomannan test in patients with agranulocytosis, use of imaging in the diagnosis of mucormycosis, risk factors for mucormycosis, indications for initiating antifungal therapy in patients with haematological malignancies, when to start empirical therapy in mechanically ventilated patients, first-line drugs for mucormycosis and treatment courses for IA and IM. CONCLUSION: This study highlights the main areas that could be targeted by training programs to improve the knowledge of physicians treating patients with IFD in China.

Ceftazidime-avibactam-based combination therapy for hospital-acquired central nervous system infections caused by carbapenem-resistant Klebsiella pneumoniae.

OBJECTIVES: Klebsiella pneumoniae (K. pneumoniae) is one of the most common bacteria in the hospital-acquired central nervous system (CNS) infections. Central nervous system infections caused by carbapenem-resistant K. pneumoniae (CRKP) are associated with significant mortality rates and high hospital costs due to limited antibiotic treatment options. This retrospective study aimed to evaluate the clinical efficacy of ceftazidime-avibactam (CZA) for the treatment of CNS infections caused by CRKP. METHODS: Twenty-one patients with hospital-acquired CNS infections caused by CRKP who received treatment with CZA for ≥ 72 hours were enrolled. The primary outcome was to assess the clinical and microbiology efficacy of CZA for the treatment of CNS infections caused by CRKP. RESULTS: A high burden of comorbidity was discovered in 20 of 21 patients (95.2%). Most patients had a history of craniocerebral surgery and 17 (81.0%) of the patients were in the intensive care unit with a median APACHE II score of 16 (IQR 9-20) and SOFA score of 6 (IQR 3-7). Eighteen cases were treated by CZA-based combination therapies, while the remaining three cases were treated with CZA alone. At the end of the treatment, the overall clinical efficacy was 76.2% (16 of 21) with a bacterial clearance rate of 81.0% (17 of 21) and all-cause mortality of 23.8% (five of 21). CONCLUSION: This study showed that CZA-based combination therapy is an effective treatment option for CNS infections caused by CRKP.

Plasma metabolomic and lipidomic alterations associated with anti-tuberculosis drug-induced liver injury.

Background: Anti-tuberculosis drug-induced liver injury (ATB-DILI) is an adverse reaction with a high incidence and the greatest impact on tuberculosis treatment. However, there is a lack of effective biomarkers for the early prediction of ATB-DILI. Herein, this study uses UPLC‒MS/MS to reveal the plasma metabolic profile and lipid profile of ATB-DILI patients before drug administration and screen new biomarkers for predicting ATB-DILI. Methods: A total of 60 TB patients were enrolled, and plasma was collected before antituberculosis drug administration. The untargeted metabolomics and lipidomics analyses were performed using UPLC‒MS/MS, and the high-resolution mass spectrometer Q Exactive was used for data acquisition in both positive and negative ion modes. The random forest package of R software was used for data screening and model building. Results: A total of 60 TB patients, including 30 ATB-DILI patients and 30 non-ATB-DILI subjects, were enrolled. There were no significant differences between the ATB-DILI and control groups in age, sex, smoking, drinking or body mass index (p > 0.05). Twenty-two differential metabolites were selected. According to KEGG pathway analysis, 9 significantly enriched metabolic pathways were found, and both drug metabolism-other enzymes and niacin and nicotinamide metabolic pathways were found in both positive and negative ion models. A total of 7 differential lipid molecules were identified between the two groups. Ferroptosis and biosynthesis of unsaturated fatty acids were involved in the occurrence of ATB-DILI. Random forest analysis showed that the model built with the top 30 important variables had an area under the ROC curve of 0.79 (0.65-0.93) for the training set and 0.79 (0.55-1.00) for the validation set. Conclusion: This study demonstrated that potential markers for the early prediction of ATB-DILI can be found through plasma metabolomics and lipidomics. The random forest model showed good clinical predictive value for ATB-DILI.

Simultaneous Detection of Pathogens and Tumors in Patients With Suspected Infections by Next-Generation Sequencing.

Background: Differential diagnosis of patients with suspected infections is particularly difficult, but necessary for prompt diagnosis and rational use of antibiotics. A substantial proportion of these patients have non-infectious diseases that include malignant tumors. This study aimed to explore the clinical value of metagenomic next-generation sequencing (mNGS) for tumor detection in patients with suspected infections. Methods: A multicenter, prospective case study involving patients diagnosed with suspected infections was conducted in four hospitals in Shanghai, China between July 2019 and January 2020. Based upon mNGS technologies and chromosomal copy number variation (CNV) analysis on abundant human genome, a new procedure named Onco-mNGS was established to simultaneously detect pathogens and malignant tumors in all of the collected samples from patients. Results: Of 140 patients screened by Onco-mNGS testing, 115 patients were diagnosed with infections; 17 had obvious abnormal CNV signals indicating malignant tumors that were confirmed clinically. The positive percent agreement and negative percent agreement of mNGS testing compared to clinical diagnosis was 53.0% (61/115) and 60% (15/25), vs. 20.9% (24/115) and 96.0% (24/25), respectively, for conventional microbiological testing (both P <0.01). Klebsiella pneumoniae (14.8%, 9/61) was the most common pathogen detected by mNGS, followed by Escherichia coli (11.5%, 7/61) and viruses (11.5%, 7/61). The chromosomal abnormalities of the 17 cases included genome-wide variations and local variations of a certain chromosome. Five of 17 patients had a final confirmed with malignant tumors, including three lung adenocarcinomas and two hematological tumors; one patient was highly suspected to have lymphoma; and 11 patients had a prior history of malignant tumor. Conclusion: This preliminary study demonstrates the feasibility and clinical value of using Onco-mNGS to simultaneously search for potential pathogens and malignant tumors in patients with suspected infections.

Intensified Antituberculosis Therapy Regimen Containing Higher Dose Rifampin for Tuberculous Meningitis: A Systematic Review and Meta-Analysis.

Background: Tuberculous meningitis is difficult to diagnose and is associated with high mortality. Recently, several studies evaluated the intensified regimen containing higher dose rifampin to treat tuberculous meningitis. However, this topic remains to be concluded. Therefore, this systematic review and meta-analysis was conducted to evaluate pharmacokinetics parameters, safety, and survival benefits of high-dose rifampin for tuberculous meningitis. Method: Data were searched from PubMed, EMBASE, The Cochrane Library, and Web of Science for studies describing an antituberculosis regimen including a higher dose of rifampin for patients with tuberculous meningitis. The quality of eligible studies was evaluated via The Cochrane Risk of Bias Tool. The meta-analysis was performed by Review Manager 5.3 software, the synthesis of the data was shown in mean difference (MD) or relative risk (RR), and 95% confidence intervals (CIs). Results: There were six randomized control trails included in this meta-analysis. The results showed that the concentration in plasma and cerebrospinal fluid (CSF) were significantly higher in the intervention group than the standard group [MD = 22.08, 95%CI (16.24, 27.92), p < 0.00001; MD = 0.74, 95%CI (0.42, 1.05), p < 0.00001], as well as the area under the time concentration curve between 0 and 24 h (AUC0-24) of rifampin [MD 203.56, 95%CI (153.07, 254.05), p < 0.00001] in plasma, but the overall survival did not improve [RR = 0.92, 95%CI (0.67, 1.26), p = 0.61]. For adverse events, the results showed a statistically significant lower incidence of hypersensitivity compared with the intervention group [RR = 1.72, 95%CI (1.13, 2.62), p = 0.01]. Fortunately, other common adverse drug reactions such as liver injury, neurological events, myelosuppression, and cardiotoxicity had no significant increase [RR = 0.98, 95%CI (0.77, 1.26), p = 0.90; RR = 1.10, 95%CI (0.94, 1.30), p = 0.23; RR = 0.82, 95%CI (0.59, 1.13), p = 0.22; RR = 1.11, 95%CI (0.66, 1.86), p = 0.70]. Conclusion: This meta-analysis suggested that the intensified treatment regimen including a higher dose of rifampin significantly increased the rifampin concentration both in the plasma and CSF, and it was safe in patients with tuberculous meningitis, but resulted in no improvement in survival rates.

Diagnosis and Management of Intraabdominal Infection: Guidelines by the Chinese Society of Surgical Infection and Intensive Care and the Chinese College of Gastrointestinal Fistula Surgeons.

The Chinese guidelines for IAI presented here were developed by a panel that included experts from the fields of surgery, critical care, microbiology, infection control, pharmacology, and evidence-based medicine. All questions were structured in population, intervention, comparison, and outcomes format, and evidence profiles were generated. Recommendations were generated following the principles of the Grading of Recommendations Assessment, Development, and Evaluation system or Best Practice Statement (BPS), when applicable. The final guidelines include 45 graded recommendations and 17 BPSs, including the classification of disease severity, diagnosis, source control, antimicrobial therapy, microbiologic evaluation, nutritional therapy, other supportive therapies, diagnosis and management of specific IAIs, and recognition and management of source control failure. Recommendations on fluid resuscitation and organ support therapy could not be formulated and thus were not included. Accordingly, additional high-quality clinical studies should be performed in the future to address the clinicians' concerns.

Clostridium difficile toxin B-induced colonic inflammation is mediated by the FOXO3/PPM1B pathway in fetal human colon epithelial cells.

Clostridium difficile (C. difficile) toxin B (TcdB) is as an inflammatory enterotoxin that accounts for manifestations of widespread healthcare-associated C. difficile infection, including colonic inflammation. The present work explored the molecular mechanism by which TcdB activates innate immunity and stimulates pro-inflammatory cytokine release. Fetal human colon epithelial cells (FHCs) were treated with recombinant TcdB protein. Cell growth inhibition and apoptosis were measured with Cell Counting Kit-8 and Annexin V-fluorescein isothiocyanate Apoptosis Detection Kit, respectively. Flow cytometry analysis was also performed. Inflammatory cytokine induction was determined with enzykeme-linked immunosorbent assay analyses. Protein expression was assessed by western blot analysis. Gene overexpression and knockdown were performed with lentiviral transduction. Real-time quantitative polymerase chain reaction was used to examine gene expression. Dual-luciferase reporter assays and chromatin immunoprecipitation were implemented to explore transcriptional regulation. Mouse colon tissues were analyzed with hematoxylin and eosin staining. The results show that TcdB-induced cell growth and apoptosis and enhanced expression of interleukin-6 and tumor necrosis factor alpha in FHCs. We identified protein phosphatase magnesium-dependent 1B (PPM1B) as the key mediator promoting the phosphorylation of nuclear factor-κB p65, which accounted for the increase in pro-inflammatory cytokines. The findings demonstrate that PPM1B expression is directly regulated by the AKT/FOXO3 signaling pathway in FHCs. We confirmed the molecular mechanism with in vivo studies using a mouse model infected with C. difficile and treated with a phosphoinositide 3-kinase/AKT signaling inhibitor. In conclusion, TcdB induces inflammation in human colon epithelial cells by regulating the AKT/FOXO3/PPM1B pathway.

Genetic variants in IFNG and IFNGR1 and tuberculosis susceptibility.

BACKGROUND: Tuberculosis (TB) is the type of chronic infectious disease which majorly caused by Mycobacterium tuberculosis (M. TB). Emerging data suggest that interferon gamma (IFNG) and its receptor IFNGR1 may be involved in the risk of TB. METHODS: A total of 636 TB patients and 608 healthy controls were selected. The association between single nucleotide polymorphisms (SNPs) and TB was estimated by logistic analyses adjusting for age, gender and smoking status. SNPs genotyping was done by using the improved multiplex ligase detection reaction (iMLDR). RESULTS: The IFNG rs1861494 allele C was related to an increased risk for TB (OR = 1.25, 95%CI: 1.06-1.48; P = 0.009). Compared with TT genotype, CT (OR = 1.28, 95%CI: 1.01-1.63; P = 0.040) and CC (OR = 1.51, 95%CI: 1.04-2.19; P = 0.031) were also risk factors for TB. In the subgroup analysis, the association was stronger among participants < 25 years (OR = 2.40, 95%CI: 1.70-3.38; P < 0.001) and male groups (OR = 1.31, 95%CI: 1.03-1.66; P = 0.030). In addition, IFNG rs1861494 was associated with anti-TB treatment outcome (OR = 0.70, 95%CI: 0.52-0.94; P = 0.017). We also detected that IFNGR1 rs2234711 influenced the IFNG production. CONCLUSION: IFNG rs1861494 polymorphism was associated with TB, particularly in the younger and male subgroups.

Evaluation of anidulafungin in the treatment of intra-abdominal candidiasis: a pooled analysis of patient-level data from 5 prospective studies.

The incidence of nosocomial invasive fungal infections involving Candida spp. has increased markedly in recent years in patients undergoing abdominal surgery. This post hoc analysis aimed to determine the efficacy and safety of anidulafungin treatment in patients with intra-abdominal candidiasis (IAC) from five prospective studies (one comparative and four open-label) of adult surgical patients with microbiologically confirmed Candida intra-abdominal infection. Patients received an intravenous (IV) loading dose of anidulafungin 200 mg, followed by a daily 100-mg maintenance dose. Per study protocols, some patients could be switched to an oral azole after ≥ 5 or ≥ 10 days of IV treatment. Antifungal treatment was maintained for ≥ 14 days after the last positive Candida culture and resolution of symptoms. The global response rate (GRR) at the end of IV treatment (EOIVT) was the primary endpoint. GRR at the end of therapy (EOT), all-cause mortality at days 14 and 28, and safety was also evaluated. Seventy-nine patients had IAC from peritoneal fluid or hepatobiliary tract. C. albicans (72.2%) and C. glabrata (32.9%) were the most common pathogens. Overall GRR was 73.4% and 67.1% at EOIVT and EOT, respectively. All-cause mortality was 17.7% at day 14 and 24.1% at day 28 in the modified intent-to-treat population. Anidulafungin was well tolerated in this population, with most adverse events mild or moderate in severity. In these patients with IAC, anidulafungin showed a GRR at EOIVT similar to the anidulafungin registrational trial, and the results of our analysis confirmed the known safety profile of anidulafungin. ClinicalTrials.gov registration number NCT00496197, registered July 3, 2007, https://clinicaltrials.gov/ct2/show/study/NCT00496197 ; ClinicalTrials.gov registration number NCT00548262, registered October 19, 2007, https://clinicaltrials.gov/ct2/show/record/NCT00548262 ; ClinicalTrials.gov registration number NCT00537329, registered September 25, 2007, https://clinicaltrials.gov/ct2/show/record/NCT00537329 ; ClinicalTrials.gov registration number NCT00689338, registered May 29, 2008, https://clinicaltrials.gov/ct2/show/study/NCT00689338 ; ClinicalTrials.gov registration number NCT00805740, registered November 26, 2008, https://clinicaltrials.gov/ct2/show/NCT00805740.

Polymorphisms of cytokine genes and tuberculosis in two independent studies.

Cytokine gene single nucleotide polymorphisms (SNPs) can influence cytokine levels, which may be associated with tuberculosis (TB) susceptibility. There is evidence that interleukin 1B (IL1B), tumor necrosis factor-alpha (TNF-alpha), and IL6 may be involved in the progression of TB. Using a self-validating case-control design, we selected eleven functional SNPs in IL1B, TNF and IL6 to detect their association with TB in Chinese Han and Tibetan populations. The associations between SNPs and TB were estimated by computing the odds ratios (ORs) and 95% confidence intervals (95% CI) using logistic regression analyses. We found that the IL1B rs16944 polymorphism was associated with decreased risk of TB in the two studies. The G allele at rs2069837 of IL6 was significantly more common in controls than in TB patients in the Han population. Moreover, TNF rs1799964 and rs1800630 were risk factors for susceptibility to TB, which were validated in the Chinese Tibetan population. In addition, TNF rs1799724 and rs1800629 were associated with TB, but only in the Tibetan population. In conclusion, SNPs of the IL1B and TNF gene were associated with TB susceptibility in Chinese Han and Tibetan populations. IL6 polymorphism may be considered as a protective factor for TB in the Chinese Han population, but not the Tibetan population.

Genetic Polymorphisms of IL1B, IL6, and TNFα in a Chinese Han Population with Pulmonary Tuberculosis.

BACKGROUND: The factors that predispose to pulmonary tuberculosis (PTB) are not fully understood. Previous studies have shown that cytokine gene polymorphisms were associated with PTB. OBJECTIVES: In this study, we have investigated the relationship between ILB, IL6, and TNFα polymorphisms and a predisposition to Mycobacterium tuberculosis (MTB) infection and PTB. METHODS: A total of 209 cases of PTB, 201 subjects with latent TB infection (LTBI), and 204 healthy controls (HCS) were included in this study. Logistic regression analyses under allelic, homozygous, and heterozygous models were used to calculate P values, odds ratios (ORs), and 95% confidence intervals (CIs) for assessing the association between single nucleotide polymorphisms (SNPs) and disease risk, adjusting for sex and age. Genotyping was conducted using the improved multiplex ligase detection reaction (iMLDR) method. RESULTS: When comparing PTB patients with LTBI subjects, significant associations with disease development were observed for SNPs of IL6 and TNFα. When comparing LTBI subjects with HCS, IL1B polymorphisms were significantly associated with LIBI. Haplotype analyses suggested that the CGG haplotype of IL1B was associated with an increased risk of PTB (P = 0.039, OR = 1.34, 95% CI: 1.01-1.76), while the TTGCG haplotype of TNFα was a protective factor against PTB (P = 0.039, OR = 0.66, 95% CI: 0.44-0.98). CONCLUSION: Our study demonstrated that IL1B variants were related to LTBI and IL6 and TNFα variants were associated with PTB.

Association between tobacco smoking and drug-resistant tuberculosis.

BACKGROUND: Tobacco smoking is a risk factor for tuberculosis but little is known about the relationship between tobacco smoking and drug-resistant tuberculosis (DR-TB). We undertook a systematic review and meta-analysis to quantitatively assess the association between DR-TB and tobacco smoking. METHODS: We searched for relevant studies in the Ovid MEDLINE, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, WANFANG, and WEIPU data-bases from inception to September 1, 2017. Results were expressed as odds ratios (ORs) with accompanying 95% CIs, and subgroup analyses were performed by study design, smoking type, DR-TB type, and multivariate analysis. RESULTS: Thirty-three studies related to tobacco smoking and DR-TB were included. We found substantial evidence that tobacco smoking is associated with an increased risk of DR-TB (OR 1.57, 95% CI 1.33-1.86). Associations were also found in subgroup analyses: for multidrug-resistant tuberculosis (OR 1.49, 95% CI 1.19-1.86) and for any DR-TB (OR 1.70, 95% CI 1.3-2.23); the pooled OR was 1.45 (95% CI 1.11-1.90) for current smoking, 2.25 (95% CI 1.46-3.47) for past smoking, and 1.56 (95% CI 1.22-1.98) for smoking history; and similar ORs were also observed in study design and multivariate analysis subgroup analysis. CONCLUSION: This study demonstrated that tobacco smoking is an independent risk factor for DR-TB.

Variants of TLR1 associated with tuberculosis susceptibility in the Chinese Tibetan population but not in Han Chinese.

Toll-like receptor 1 (TLR1) participates in the innate immune response to Mycobacterium tuberculosis. This study mainly investigated the relationship between polymorphisms of TLR1 and tuberculosis (TB) susceptibility in the two Chinese populations. Totally, 1185 Han and 1216 Tibetan participants were enrolled. TagSNPs of TLR1 were selected and genotyped. Analyses of linkage disequilibrium and haplotypes were performed by software Haploview and SHEsis. Gene-gene interactions were evaluated using the nonparametric multifactor dimensionality reduction (MDR) method. Gene-by-sex interaction in the Tibetan population and gene-by-smoking interaction in the Han population were also calculated. Association between rs4833095 and TB susceptibility was evaluated by meta-analysis. In the Tibetan population, the A alleles of rs5743557 and rs5743596 were related with reduced tuberculosis risk (p < 0.001 and p = 0.001) after adjusting for confounding factors. Additionally, rs5743604_A was associated with increased TB susceptibility (p = 0.004). The frequency of haplotype rs4833095-rs5743557-rs5743596-rs5743604 CAAG was significantly higher in the healthy controls (HC) group (p = 0.0009), while frequency of haplotype CGGA was higher in the TB group (p = 0.001). Significant associations were detected between rs4833095-rs5743557-rs5743604 interactions and TB susceptibility. Interactions between rs5743596 and sex in the Tibetan population, between rs5743604 and smoking in the Han population were revealed as well. However, no significant main effects were observed in the Han population. The rs4833095 was not associated with TB susceptibility after meta-analysis either. Our study suggested that SNPs of the TLR1 gene were associated with TB susceptibility in the Chinese Tibetan population, but not in the Han population.

Bone marrow granulomas in a high tuberculosis prevalence setting: A clinicopathological study of 110 cases.

Granulomas were reported in 0.3% to 3% of bone marrow biopsies. The aim of the study was to evaluate the incidence and etiology of bone marrow granulomas (BMGs) in the West China Hospital, which located at a high tuberculosis (TB) prevalence area in China.A retrospective case review was performed on 11,339 bone marrow biopsies at the West China Hospital of Sichuan University between January 2011 and December 2015. Cases with BMGs were retrieved and their clinical data and histopathological features were collected, examined, and analyzed.Out of 11,339, 110 cases showed granulomatous lesions in the bone marrow biopsies (0.97%). Etiologies were indentified in 80 cases (72.8%), with infections being the most common (64.5%), following by malignancies (4.5%) and autoimmune diseases (3.6%). Among infectious cases, 87.32% (62/71) cases were diagnosed as TB, a positive acid-fast stain or/and polymerase chain reaction (PCR) result for mycobacterium TB DNA fragment amplification was obtained for 35 cases. In 30 cases (27.27%), a definite diagnosis could not be established.In a TB high prevalence region in China, with a combined histological, clinical, serological, and molecular approach, we were able to clarify the cause in 72.73% of the bone marrow granulomatous cases. TB is the most common underlying etiologies. Therefore, acid-fast stain and quantitative PCR for mycobacterium TB DNA amplification are recommended as a routine for bone marrow biopsies in TB high prevalence regions.

[Association of rs1495741 Single Nucleotide Polymorphism with Susceptibility of Anti-tuberculosis Drug-induced Hepatotoxicity].

OBJECTIVE: To investigate the potential association between the polymorphism of N- acetyltransferase 2 (NAT2) gene and anti-tuberculosis drug-induced hepatotoxicity (ATDH) in Han population. METHODS: The SNP rs1495741 was genotyped by using multiplex ligation detection reaction (MLDR) technique, and logistic regression analysis was used to analyze the association between this SNP and the susceptibility of ATDH. RESULTS: There were 247 PTB patients enrolled in this study, including 24 ATDH, and 223 controls (PTB without ATDH). No significant difference in genotype and allele distribution was observed for rs1495741 in NAT2 between the controls and ATDH group. After adjusting age, sex, body mass index (BMI) and smoking history, the SNP of rs1495741 showed a significant association with ATDH 〔odds ratio (OR)=2.728 (95% confidence interval: 1.022-7.281)〕 under recessive model (AA vs. GA+GG). CONCLUSIONS: The rs1495741 in NAT2 seems related to the development of ATDH among PTB patients, AA genotype of rs1495741 may be a causative factor for increased susceptibility to ATDH.

Emergence of tigecycline- and carbapenem-nonsusceptible Klebsiella pneumoniae ST11 clone in patients without exposure to tigecycline.

BACKGROUND/PURPOSE: Currently, tigecycline-nonsusceptible Klebsiella pneumoniae (TNSKP) is mainly reported to emerge following clinical use of tigecycline and is usually polyclonal. This study aimed to characterize TNSKP isolated from patients without prior tigecycline use. METHODS: Twenty-six TNSKP clinical isolates were collected, and carbapenemase and 16S rRNA methylase genes were identified by polymerase chain reaction and sequencing. Molecular typing was conducted by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Clinical data of patients in the carbapenem-susceptible TNSKP group and the tigecycline- and carbapenem-nonsusceptible K. pneumoniae (TCNSKP) group were compared. RESULTS: Of the 26 TNSKP isolates, eight contained both blaKPC-2 and 16S rRNA methylase genes. In the remaining 18 TNSKP isolates, no carbapenemase gene was detected, and only three had the 16S rRNA methylase gene. Among the 26 isolates, 24 distinct pulsotypes and 19 sequence types (STs) were identified by PFGE and MLST, respectively. Six of the eight TCNSKP were ST11, whereas the remaining 18 TNSKP isolates were assigned to 17 different STs. No patient received tigecycline prior to the isolation of TNSKP. By comparison, intensive care unit exposure, mechanical ventilation, prior ß-lactam/ß-lactamase use, and longer hospitalization were more common for the TCNSKP group than for the carbapenem-susceptible TNSKP group. CONCLUSION: TNSKP can occur without tigecycline use, and TCNSKP ST11 is predominant among them. Further, this report proposes potential risk factors for the occurrence of carbapenem-nonsusceptibility in TNSKP.

Sulbactam-based therapy for Acinetobacter baumannii infection: a systematic review and meta-analysis

BACKGROUND: A number of studies have reported on the effectiveness of sulbactam-based therapies for Acinetobacter baumannii infection; however, there is little evidence that sulbactam-based therapies are more or less effective than alternative therapies. Unfortunately, there is a distinct lack of high quality data (i.e., from randomized controlled trials) available on this issue. Therefore, we conducted a systematic review and meta-analysis comparing the efficacy of sulbactam-based and non-sulbactam-based regimens in the treatment of A. baumannii infection. METHODS: We searched PubMed, MEDLINE, Biomedical Central, Google Scholar, the China National Knowledge Infrastructure, the Cochrane library, and the Directory of Open Access using the terms "sulbactam and baumannii" or "maxtam and baumannii". Randomized controlled trials, controlled clinical studies, and cohort studies were considered for inclusion. The primary outcome was the clinical response rate for sulbactam-based therapy vs comparator therapies. RESULTS: Four studies (1 prospective, 3 retrospective) were included in the metaanalysis. Sulbactam was given in combination with ampicillin, carbapenem, or cefoperazone (n = 112 participants). Comparator drugs included colistin, cephalosporins, anti-pseudomonas penicillins, fluoroquinolones, minocycline/doxycycline, aminoglycosides, tigecycline, polymyxin, imipenem/cilastatin, and combination therapy (n = 107 participants). The combined clinical response rate odds ratio did not significantly favor sulbactam-based therapy over comparator therapy (odds ratio = 1.054, 95% confidence interval = 0.550-2.019, p = 0.874), nor did any of the individual study odds ratios. CONCLUSIONS: The available evidence suggests that sulbactam-based therapy may be similarly efficacious to alternative antimicrobial therapies for the treatment of A. baumannii infection. Further research on this issue is warranted given the limited availability of data from high quality/randomized controlled trials.

Comparison of adhesin genes and antimicrobial susceptibilities between uropathogenic and intestinal commensal Escherichia coli strains.

The presence of adhesins is arguably an important determinant of pathogenicity for Uropathogenic Escherichia coli (UPEC). Antimicrobial susceptibilities were tested by agar dilution method, fifteen adhesin genes were detected by polymerase chain reaction, and multilocus sequence typing (MLST) was analyzed in 70 UPEC isolates and 41 commensal E. coli strains. Extended-spectrum ß-lactamase (ESBL) was determined with confirmatory test. The prevalence of ESBL-producers in UPEC (53%, 37/70) was higher than the commensal intestinal isolates (7%, 3/41), and 97% (36/37) of the ESBL-producing UPEC harbored bla CTX-M genes. afa was present in 36% (10/28) UPEC isolates from recurrent lower urinary tract infection (UTI), and none in the acute pyelonephritis, acute uncomplicated cystitis or commensal strains (P<0.0001). papG was detected in 28% (20/70) of UPEC isolates, while 5% (2/41) of the commensal strains were papG positive (P = 0.0025), and the prevalence of papG was significantly higher in acute pyelonephritis group (71%) than the other two UTI groups (P<0.0001). The prevalence of flu, yqi, yadN and ygiL was significantly higher in UPEC isolates than in the commensal strains. ESBL-producing UPEC showed a lower prevalence of adhesin genes compared with non-ESBL-producing strains. The MLST profiles were different between UPEC and commensal strains, with ST131 (19%, 13/70) and ST10 (20%, 8/41) being the most common MLSTs, respectively. This study demonstrated that several adhesin genes were more prevalent in UPEC isolates than in commensal E. coli, and afa may be associated with recurrent lower UTI whereas papG is more frequently associated with acute pyelonephritis.

Co-production of SFO-1 and DHA-1 ß-lactamases and 16S rRNA methylase ArmA in clinical isolates of Klebsiella pneumoniae.

OBJECTIVES: To investigate the epidemiology and genetic characteristics of the plasmid-mediated extended-spectrum ß-lactamase (ESBL) gene bla(SFO-1) in clinical isolates of ESBL-producing Klebsiella pneumoniae and Escherichia coli. METHODS: The prevalence of the bla(SFO-1) gene was examined by PCR amplification. Conjugation and transformation experiments were performed and the presence of antimicrobial resistance determinants was investigated by the PCR method. The genetic environments of the bla(SFO-1) and armA genes were determined by direct sequencing of plasmid pHS20. Plasmids were typed by PCR-based replicon typing. PFGE and multilocus sequence typing were performed on SFO-producing strains. RESULTS: Of 158 ESBL-producing strains of K. pneumoniae, 3 (1.9%) carried the bla(SFO-1) gene. All of the SFO-producing isolates belonged to the ST11 epidemic clone, with a single PFGE type and had high-level resistance to third-generation cephalosporins, aminoglycosides and ciprofloxacin. The bla(SFO-1) gene was co-transferred with the armA, aac(6')-Ib-cr and bla(TEM-1) genes by transformation, whereas the armA, bla(DHA-1) and qnrB4 genes were co-transferred by conjugation. The armA genes were located within the composite transposon Tn1548 on two different plasmids in the strain 08-129. The bla(SFO-1) gene was located upstream of an ampR gene from the coding region and flanked by two inverted repeats of IS26. Plasmids carrying bla(DHA-1) were identified as IncFII, while the bla(SFO-1)-bearing plasmids were non-typeable. CONCLUSIONS: Although SFO-1 is a low-occurrence ESBL, it has been captured by a plasmid accumulating multiple resistance determinants including armA and aac(6')-Ib-cr, and accompanied by a large DHA-1-bearing IncFII plasmid in a prevalent K. pneumoniae ST11 clone.