Epidemiological, clinical characteristics and drug resistance situation of culture-confirmed children TBM in southwest of China: a 6-year retrospective study.

BACKGROUND: Sichuan is a province located in southwestern China, which have a higher incidence of tuberculosis (TB). This study aimed to analyze the epidemiological and clinical characteristics, as well as drug resistance in culture-confirmed children with Tuberculosis meningitis (TBM) in Southwest of China. METHODS: We performed a retrospective study on children (< 14 years old) with cerebrospinal fluid (CSF) culture-confirmed TBM between January 2013 and December 2018 at Public Health Clinical Center of Chengdu (PHCCC). Mycobacterium tuberculosis (MTB) drug sensitivity testing (DST) was performed using the MicroDST™ method. The age, gender, family history of tuberculosis, status of Bacillus Calmette-Guérin (BCG) vaccination, residential areas information, clinical, laboratory, and radiological features were recorded. Data were analyzed using SPSS Statistics Client 25.0, and the change in drug resistance rate was examined using the Cruskal-Wallis test. RESULTS: Among 319 patients clinically diagnosed with TBM, 42 (13.2%) were Mycobacterial culture positive. Their median age was nine years, and the distribution was equal among female and male patients. Among 42 patients who were enrolled in the study, 1/42 (2.38%) passed away. Children with TBM were concentrated in the minority areas of western Sichuan, where 34/42 (81.0%) patients with TBM belonged to ethnic minorities, and only 2/42 (4.76%) received BCG vaccination in the past. Chest X-rays changes were observed in all patients. Fever and headache were the most common presenting symptom. Thirty-five (83.3%) patients suffered from neck stiffness, and 30/42 (71.4%) had high CSF pressure. DST results showed that the resistance rate was high; resistance to any anti-tuberculosis drug (ATD) was observed in 13 (31.0%) patient isolates, while multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) were found in 2 (4.8%) and 1 (2.4%) patients, respectively. CONCLUSIONS: TBM among children in Southwest China was mainly concentrated in the minority areas of western Sichuan and more than 95% of patients did not receive BCG vaccination at birth. The most common symptoms were fever, headache, and neck stiffness and all patients had positive chest X-ray findings. In addition, high rates of drug resistance were found.

[Clinical Epidemiological Characteristics of Newly Reported HIV/AIDS in a Certain General Hospital from 2001 to 2017].

OBJECTIVE: To determine the clinical epidemiological characteristics of newly reported human immunodeficiency virus/acquired immunodeficiency syndrome （HIV/AIDS）in southwestern China from 2001 to 2017. METHODS: Clinical data of newly diagnosed HIV/AIDS from 2001 to 2017 in the West China Hospital of Sichuan University were reviewed and analyze. RESULTS: A total of 1 520 228 patients were screened for HIV, including 285 983 outpatient and emergency patients and 1 234 245 inpatients. About 4 037 (0.27%) patients were confirmed with HIV/AIDS. The confirmation rate increased from 2001 to 2013, followed by a slight decline from 2014 to 2017. The male to female sex ratio of confirmed HIV/AIDS was 3.49:1 from 2001 to 2017, ranging from 1.65:1 to 5.08:1. The majority of patients were identified as Han (88.23%), had low education (58.66%), and married (54.75%). Peasants/herdsman comprised 26.33% of the patients. The proportion of young (15-29 years old), and middle-aged (≥50 years old) patients and those who were unmarried and had high education (senior high school and above) increased over time. Heterosexual transmission remained stable at about 60% while homosexual transmission increased by about 15% ( χ 2=14.436, P＜0.005) since 2008. Transmissions through drug abuse( χ 2=71.633, P＜0.005) and blood( χ 2=16.672, P＜0.005) decreased. Of the 899 female newly reported HIV/ADIS patients, 77.20% were infected through heterosexual relationship. In comparison, of the 3 138 male patients, 61.41% were infected through heterosexual and 18.10% through homosexual relationships. Homosexual transmissions decreased with age, but heterosexual transmissions increased with age. Mother-to-child transmissions were concentrated in those between 0 and 15 years old (100%). CONCLUSION: Newly diagnosed HIV/AIDS cases increased over the years in the West China Hospital of Sichuan University, in particular in those of young and middle-aged, highly educated and unmarried. Heterosexual transmissions remain the main route.

Performance of serum HBcrAg in chronic hepatitis B patients with 8-year nucleos(t)ide analogs therapy.

AIM: This study aimed to investigate long-term kinetics of serum hepatitis B core-related antigen (HBcrAg) and its correlation with serum hepatitis B surface antigen (HBsAg) in a real-world cohort of patients who had received over 8 years of nucleos(t)ide analogs(NAs) therapy. METHODS: This was a retrospective study. All patients were recruited from our previous published study, who started therapy with NAs between 2007 and 2008. Serum HBcrAg and HBsAg levels were quantitatively measured at baseline, the sixth month and each year of follow-up, using the stored serum samples. RESULTS: Among the 94 patients, serum HBcrAg presented a gradually decreasing trend from baseline to year 8, either in HBeAg-negative or HBeAg-positive patients. After 8 years of NAs treatment, 21.3% of patients achieved serum HBcrAg < 3 log 10 U/mL, and only baseline HBcrAg was an independent predictor. Additionally, good correlation of HBcrAg and HBsAg was observed at baseline, but this correlation weakened remarkably during treatment. CONCLUSION: Serum HBcrAg is decreasing gradually with the duration of antiviral therapy, and baseline HBcrAg level is an independent predictor of long-term HBcrAg below the limit of detection.

Pronounced decline of serum HBsAg in chronic hepatitis B patients with long-term effective nucleos(t)ide analogs therapy.

AIMS: This study aims to investigate the kinetics of serum HBsAg levels in chronic hepatitis B patients with long-term nucleos(t)ide analogs (NAs) therapy. METHODS: This was a retrospective clinical study. Serum HBsAg in serial samples of 94 patients, who received at least 8 years of NAs therapy, were measured using Elecsys® HBsAg II Quant Assay. RESULTS: In this cohort, serum HBsAg levels reduced from 3.80 log10 IU/mL at baseline to 2.72 log10 IU/mL at year 8 (p < .001), and the percentage of patients with HBsAg <1000 IU/mL increased from 14.9% at baseline to 55.3% at year 8 (p < .001). The reduction of serum HBsAg did not differ significantly between patients stratified by baseline virological parameters and type of antiviral agents. But as compared to patients without HBeAg seroconversion, HBsAg levels were significant lower in patients with HBeAg seroconversion (3.19 vs. 2.47 log10 IU/mL at year 8, p = .001). As compared to patients with slow (0-1 log10 IU/mL) or steady HBsAg(≤0 log10 IU/mL) decline at year 1, patients with a rapid HBsAg (≥1 log10 IU/mL) decline had a significantly lower HBsAg levels from year 2 to 8. However, Cox regression analysis showed that only absolute HBsAg levels at year 1 was an independent predictor of subsequent HBsAg <1000 IU/mL at year 8 of antiviral therapy(HR 0.242, p = .004). CONCLUSION: Pronounced HBsAg declines could be achieved in patients after long-term effective therapy with NAs, and on-treatment low serum HBsAg level at year 1 might be a predictor of serum HBsAg <1000 IU/mL at year 8.

Serum hepatitis B core-related antigen is a satisfactory surrogate marker of intrahepatic covalently closed circular DNA in chronic hepatitis B.

Recently, hepatitis B core-related antigen (HBcrAg) has been suggested as an additional marker of hepatitis B virus (HBV) infection. This study aimed to investigate whether serum quantitative HBcrAg (qHBcrAg) was a satisfactory surrogate marker of intrahepatic covalently closed circular DNA (cccDNA). A total of 139 patients with liver biopsy were enrolled, consisting of 59 patients in immune tolerance (IT) phase, 52 patients in immune clearance (IC) phase, 18 patients in low-replication (LR) phase, and 10 patients in reactivation phase. All patients in IC phase have received entecavir (ETV) therapy, and 32 of them undergone a second liver biopsy at 24 months. Among those patients, qHBcrAg was strongly correlated with intrahepatic cccDNA, which is superior to that of qHBsAg and HBV DNA. And similar findings were also observed in patients in IT, IC, LR and reactivation phases. Among the 32 ETV-treated patients with a second liver biopsy in IC phase, the decline of intrahepatic cccDNA was accompanied by changes in both qHBcrAg and qHBsAg. However, as compared to qHBsAg, the change of qHBcrAg was more strongly associated with intrahepatic cccDNA-decline. In summary, serum qHBcrAg should be a satisfactory surrogate of intrahepatic HBV cccDNA in CHB patients.

Concomitant systemic lupus erythematosus and HIV infection: A rare case report and literature review.

RATIONALE: Coexisting systemic lupus erythematosus (SLE) and human immunodeficiency virus (HIV) infection cases are rare worldwide. Great challenges are posed on the diagnosis and treatment of such concurrent cases. PATIENT CONCERN: We report the case of a 44-year-old Chinese man with edema, hematuria, and fever who presented at West China Hospital, Sichuan University, Chengdu, Sichuan, China, in 2013. DIAGNOSES: An initial diagnosis of SLE was made from the clinical manifestations and laboratory findings based on the Systemic Lupus International Collaborating Clinics classification criteria. Immunosuppressant therapy relieved him of the edema and hematuria, but he regained the symptoms after a cold. Workup, including electrochemiluminescence immunoassay, western blot, and polymerase chain reaction analysis, revealed that he was concurrently infected with HIV after hospitalization. INTERVENTIONS: The treatment plan included methylprednisolone and cyclophosphamide, with gastroprotective and hepatoprotective agents, simultaneously aiming to reduce urinary protein. After HIV infection confirmed, cyclophosphamide was stopped. He was referred to the local Centers for Disease Control and Prevention for combination antiretroviral therapy (ART). He was suggested to continue monitoring CD4 T-cell count for an appropriate dose of immunosuppressive drugs. OUTCOMES: In the last follow-up in May 2017, he had been stable in terms of both SLE and HIV infection. LESSONS: The case highlights the presence of concurrent SLE and HIV infection. Laboratory technicians and clinicians should be cautious on diagnosis, especially in eliminating the false-positive results. Attention should be paid to the dose of immunosuppressants and the ART procedure.

Evaluation of the Elecsys(®) Anti-HCV II assay for routine hepatitis C virus screening of different Asian Pacific populations and detection of early infection.

BACKGROUND: Early diagnosis of hepatitis C virus (HCV) infection is essential to allow appropriate treatment and prevent transmission. OBJECTIVES: To evaluate the Elecsys(®) Anti-HCV II assay as a routine screening assay in Asia using a large number of samples from different Asian Pacific populations and compare its performance with other HCV assays routinely used in the region. STUDY DESIGN: The sensitivity and specificity of the Elecsys(®) Anti-HCV II assay were determined using routine hospital samples and compared with at least one of the following comparator assays at nine independent centers: ARCHITECT™ Anti-HCV; Serodia(®)-HCV Particle Agglutination; Vitros(®) ECi Anti-HCV; Elecsys(®) Anti-HCV; ADVIA Centaur(®) HCV; InTec(®) HCV EIA; or Livzon(®) Anti-HCV. Commercially available seroconversion panels were used to assess sensitivity for early detection of infection. RESULTS: The Elecsys(®) Anti-HCV II assay was more sensitive in recognizing early infection and detected acute HCV infection earlier on average than the comparator assays for all six panels tested. 7,726 routine samples were tested and 322 identified as HCV positive. Elecsys(®) Anti-HCV II had a sensitivity of 100% and a specificity of 99.66%, both of which were comparable or superior to the results obtained for competitor assays, which ranged from 87.5-100% and 98.98-100%, respectively. CONCLUSIONS: The Elecsys(®) Anti-HCV II assay has the sensitivity and specificity to support its use as a routine screening method in the Asia Pacific region. Furthermore, this assay shortens the diagnostic window between infection and the detection of antibodies compared with established methods.

Validation of the Elecsys® HIV combi PT assay for screening and reliable early detection of HIV-1 infection in Asia.

BACKGROUND: The Elecsys® HIV combi PT assay was developed to allow earlier detection of HIV infection with increased sensitivity and specificity. OBJECTIVES: To validate the assay for screening and reliable early detection of HIV-1 infection in Asia. STUDY DESIGN: Samples tested reflected those routinely screened in Asia and comprised: HIV-1 antigen lysate (25 samples) and antibody (20 samples) dilutions; seven HIV-1 seroconversion panels (46 samples); 39 patient samples from early infection; 183 known-positive sera; HIV-1 p24 antigen sensitivity panel (seven samples); >500 routine clinical samples per center. The Elecsys® HIV combi PT assay was compared with fourth- (ADVIA Centaur® HIV combo, ARCHITECT® HIV combo, Elecsys® HIV combi) and third-generation (VIRONOSTIKA® HIV Uni-Form II Plus O, Zhuhai Livzon Anti-HIV EIA, Serodia® Particle Agglutination) assays commonly used in the region. RESULTS: Overall, the Elecsys® HIV combi PT showed superior or similar sensitivity to the comparators for detecting all subtypes. The assay correctly identified all positive samples, including those taken soon after infection, and detected seroconversion at a similar or shorter time interval than the comparators. The analytical sensitivity of Elecsys® HIV combi PT for HIV-1 p24 antigen was 0.90 IU/mL, which was lower than reported previously. The assay showed good specificity (99.86%) that was superior or equivalent to the other fourth-generation assays tested. CONCLUSIONS: These robust data demonstrate the good subtype inclusivity of the Elecsys® HIV combi PT assay and its suitability for screening and reliable early detection of HIV infection in Asia.

Quantitative hepatitis B surface antigen titres in Chinese chronic hepatitis B patients over 4 years of entecavir treatment.

BACKGROUND: The clinical value of quantitative hepatitis B surface antigen (qHBsAg) titre in patients taking nucleotide/nucleoside analogues (NAs) is still controversial. This study aims to investigate the dynamic changes of qHBsAg titres and their significance for predicting virological response (VR) and serological response (SR) to long-term entecavir (ETV) treatment. METHODS: A total of 48 ETV-naive patients were enrolled and followed prospectively for 4 years, 32 of whom were hepatitis B e antigen (HBeAg)-positive at baseline. Serum alanine aminotransferase (ALT), qualitative HBV serological markers and HBV DNA were detected; qHBsAg titres were measured using Elecsys(®) HBsAg II Quant Assay (Roche Diagnostics, Penzberg, Germany). RESULTS: The mean baseline HBV DNA and qHBsAg were 7.51 log10 copies/ml and 3.78 log10 IU/ml, respectively. After 48 months of ETV treatment, the rates of VR (<291 copies/ml), ALT normalization and SR (HBeAg/antibody to HBeAg [anti-HBe]) were 89.6% (43/48), 89.6% (43/48) and 34.4% (11/32), respectively. There was a decrease in qHBsAg titres from baseline to month 48, ranging from 3.78 to 3.10 log10 IU/ml. The greatest decrease of qHBsAg was observed in the first 3 months of treatment (0.47 log10 IU/ml), which was significantly correlated with corresponding HBV DNA decreases (3.89 log10 copies/ml; P=0.032). By using receiver operating characteristic (ROC) curve analysis, qHBsAg titres at baseline (area under the curve [AUROC]=0.647) and 3 months after treatment (AUROC=0.586) had poor power in predicting 48-month VR; qHBsAg titres at baseline (AUROC=0.779) and 3 months after ETV treatment (AUROC=0.658) had poor power in predicting 48-month SR in patients who were HBeAg-positive at baseline. Additionally, the decrease of qHBsAg in the first 3 months of treatment also had poor power in predicting either 48 month VR or SR. CONCLUSIONS: ETV is efficacious in NA-naive patients, and qHBsAg titres decreased significantly in the first 3 months of ETV treatment. However, qHBsAg titre was not a good predictor of 4-year VR and HBeAg/anti-HBe SR in this cohort.

Reference intervals and factors contributing to serum cystatin C levels in a Chinese population.

BACKGROUND: Serum cystatin C (Cys-C), an inhibitor of cysteine proteases, has been suggested as an ideal biomarker of glomerular filtration rate (GFR). OBJECTIVES: The objective of this study was to describe the reference intervals of serum Cys-C and identify factors associated with serum Cys-C or its variability, including age, gender, creatinine (Crea), blood urea nitrogen (BUN), and uric acid (UA). DESIGN AND METHODS: Serum Cys-C, Crea, BUN, and UA were measured in 4,517 healthy participants aged 8-89 years attending our hospital. Serum Cys-C was analyzed using a latex-enhanced immunoturbidimetric method. Crea were tested by picric acid jaffe method, BUN, and UA by kinetic UV assays. RESULTS: The predominant characteristic of Cys-C distribution was that Cys-C concentration in age ≥60 years group was the highest (P < 0.05). The differences of Cys-C concentration between males and females existed for subjects aged from 30 to 59 years (P < 0.05). In a multiple model adjusted only for gender and age, gender (ß = 0.007) has stronger effect on Cys-C levels, compared with age (ß = 0.003). The clinical variables, comprised of age, gender, Crea, BUN, and UA, involved in the fully adjusted equation accounted for 37.6% of variation of Cys-C. CONCLUSIONS: Ninety-five percent reference intervals for healthy population were partitioned into three categories only by age, 0.59-1.07 mg/L for subjects aged 19-59 years; 0.74-1.14 mg/L for the older aged ≥60 years; and 0.63-1.11 mg/L for children aged ≤18 years. Serum Cys-C is significantly related to gender, age, UA, Crea, and BUN. Besides, there are still other factors contributing to variation of Cys-C levels.

[Etiology of infections in the wounded victims of Wenchuan Earthquake].

OBJECTIVE: To analyze the etiology of infections in the wounded victims of Wenchuan Earthquake. METHODS: 2135 smears of secretion were made from 1823 hospitalized wounded victims of Wenchuan Earthquake to detect the pathogens. Specimens were delivered to be cultured. The bacteria thus obtained were identified. Drug sensitivity test was conducted. RESULTS: 2002 specimens, 1243 specimens of secretion (62.1%), 600 blood specimens (30.0%), 102 specimens of pus or secretion of respiratory tract (5.1%), 45 specimens from catheter (2.2%), and 12 urine specimens (0.5%). Pathogens were found in 725 cases. The top five pathogenic bacteria isolated within 1 month after the quake were Acinetobacter baumannii (16.7%), Staphylococcus haemolyticus (16.7%), Escherichia coli (12.5%), Klebsiella pneumoniae (12.5%), and Candida tropicalis (8.3%), quite different from the pathogen spectrum of the common in-patients within one month before the quake: Escherichia coli (18.2%), Staphylococcus aureus (11.4%), Candida glabrata (11.4%), Klebsiella pneumoniae (11.4%) and Staphylococcus epidermidis (9.1%). The isolation rate of methicillin resistant Staphylococcus aureus after the earthquake was significantly lower, and the isolation rates of extended spectrum beta-lactamase-producing Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca were all significantly higher than those from the common surgical patients before the quake (all P < 0.05). There were not significant differences in the isolation rates of multi-drug resistant Pseudomonas alcaligenes and Acinetobacter baumannii before and after the quake. CONCLUSION: Infection is frequent after natural disasters. It is necessary to summarize the changes of spectrum of pathogens and drug-resistant spectrum.

[The influence of lysogenic phage on biofilm formation of Pseudomonas aeruginosa].

OBJECTIVE: To investigate the effect of the lysogenic phage Ppa3094 on the biofilm formation of PA3094. METHODS: The modified plate culture method was used to established the biofilm model in vitro. The viable counts of bacteria in biofilm were detected by MTT method; The real-time RT-PCR was applied to measure the expression level of algC and algD during the biofilm formtion of PA3094 and PA3094-L. RESULTS: Biofilm of both strains were mature at 5th to 7th day. The structures of the biofilms were both like pellicle. There was a significant difference in the viable counts of bacteria during biofilm development between PA3094 and PA3094-L. The expression of algC and algD genes was upregulated during biofilm formation. However, the expression level of PA3094-L was lower than PA3094, especially algC at 12 h. CONCLUSION: The lysogenic phage Ppa3094 could influence the biofilm formation during its development through changing the expressing level of the alginate biosynthetic genes.

[An analysis of long term prophylaxis of virus recurrence with antiviral treatment in HBV infected liver transplant recipient patients].

OBJECTIVE: No optimal prophylactic protocol of hepatitis B immunoglobulin (HBIG) combined with nucleos(t)ide analogue for HBV recurrence has been established yet. By investigating the alterations of HBV markers in HBV related liver disease patients, recipients of a liver transplant, under lamivudine or/and HBIG prophylaxis, we aim to explore the possible HBV recurrence mechanism involved and to find a new option in the prophylaxis of HBV recurrence and to tailor individualized therapy. METHODS: Serial liver biopsy specimens and sera were obtained intraoperationally and at definite time points during follow-up. ELISA and chemiluminescent microparticle immunoassay, HBV DNA fluorescent quantification, immunohistochemistry staining and HBV DNA in situ hybridization were performed. Alterations of HBV markers in specimens of 96 liver transplant recipients were investigated retrospectively. RESULTS: All 17 cases had HBV recurrence (median 37 months) which occurred in the follow-up period after liver transplantation. The overall actual HBV recurrence rate at 2 years was 22% with a significant difference between that of the active and inactive groups (P<0.05); 82.4% HBV recurrence took place within the first 3 years after the operation, and the recurrence ratio of first 3 years to 3 years later after transplantation was 4.7 (P<0.01). The HBV DNA positive patients accounted for 78.6% of the total number of recurrences within the first 3 years. HBcAb and HBeAb positive rates went down with time, but their positivity remained. CONCLUSION: HBV recurrence happens after liver transplantation. In inactive HBV replicative patients with strictly combined prophylaxis and availability of other medications and using 3 years after liver transplantation as a point of time, we think that tapering down the dosage of HBIG and tailoring individualized treatment methods based on virological and immunological situations of each recipient are worth trying.

[Analysis of class I integrons in metalloenzyme-producing Pseudomonas aeruginosa].

OBJECTIVE: To investigate class I integrons and integrated gene cassettes in metalloenzyme-producing Pseudomonas aeruginosa. METHODS: A total of 68 isolated clinical strains of Pseudomonas aeruginosa were subjected to PCR analysis with primers specific for bla(IMP-1) and bla(VIM). The positive strains then underwent examination for class I integrons and integrated gene cassettes with PCR with primers specific to class I integrase ((IntI)1) and integrated gene cassettes, followed by sequence analysis for some of the positive strains. RESULTS: Only 1 isolated strain showed positive results for both bla(IMP-1) and bla IntI1 detection. Fifty-five strains were positive for bla(VIM), including 26 positive for bla (IntI)1. Of the 26 bla (IntI)1-positive strains, only 18 contained integrated gene cassettes, which were classified into 5 types according to agarose gel electrophoresis. CONCLUSION: It is the first time to identify IMP-1-producing Pseudomonas aeruginosa carring bla(Int)1 in West China. The class I integrons were widespread in these Pseudomonas aeruginosa and 69.2% of them carry the gene cassettes. These findings provide useful insights into the clinical spread of these drug-resistant genes.

[Investigating the fluoroquinolone molecular resistant mechanism of Stenotrophomonas maltophilia].

OBJECTIVE: To research DNA gyrase and topoisomerase IV quinolone resistance-determining regions (QRDRs) in Stenotrophomonas maltophilia clinical isolates with different resistant levels of quinolone susceptibility. METHODS: We selected five strains for which the MIC of ciprofloxacin were higher than 2 mg/L and were negative for efflux mechanism; then we amplified their QRDRs of gyrA and parE, purified the fragment, and analyzed the nucleotide sequences. RESULTS: In Stenotrophomonas maltophilia DNA gyrA, the changes at positions 83 and 87 commonly involved in quinolones resistance in gram-negative bacteria were absent, and there was Gln but not Ser or Thr. Of the five strains, one strain showed a ParE amino acid change in position 402, the other was in position 432, but the mutations were not associated with FQNS resistance. CONCLUSION: FQNS resistance in Stenotrophomonas maltophilia is related to active efflux pump and may be correlated with a low level of permeability. But it is not clear whether the resistance is related to the mutants in DNA gyrase and topoisomerase N.

[Application of M-RAPD technique to obtain the genomic fingerprints of various pathogenic microbials].

OBJECTIVE: To obtain genomic fingerprints of different pathogenic microbials and make certain whether their patterns can be used in the identification of microbials by means of multiplex random amplified polymorphic DNA analysis (M-RAPD). METHODS: Arbitrary primers of 10 oligonucleotides were randomly grouped, and various microbials chromosomal DNA were amplified with three combinatorial primers at a special higher annealing temperature. The products were detected by 15 g/L agarose electrophoresis and the patterns were analyzed by the software of Gelworks 1d Intermediate. RESULTS: Specific and resistant DNA fingerprints for different pathogenic microbials with combinatorial primers were gained. The profiles were clear, well-distributed and the number was great. The products of the three primers included most products of every two primers and would appear with no relation to their length, but small products had more opportunity; three primers could provide information contents half as many again as that two primers could provide for the same pathogenic microbials. There were obvious differences among different drug-resistant strains and between the drug-resistant strains and the corresponding reference strains, but different strains of the same microorganism had more similarity than discrepancy. The analytic data of the software of Gelworks 1d Intermediate also support our results. CONCLUSION: M-RAPD is a simple and rapid technique for the identification of different kinds of pathogenic microbials, and it can provide rich genetic information.

[Surveillance on antibiotic resistance of Stenotrophomonas maltophilia in Chengdu and Chongqing area].

OBJECTIVE: To survey the antibiotic resistance of Stenotrophomonas maltophilia in Chengdu and Chongqing area and guide the rational antibiotics usage in the treatment of Stenotrophomonas maltophilia infection. METHODS: Minimal inhibitory concentrations (MICs) of 9 antibiotics against Stenotrophomonas maltophilia were measured using two-fold agar dilution method. RESULTS: A total of 154 strains of Stenotrophomonas maltophilia are multi-drug resistant. But the resistant ratios of trimethoprim-sulfamethoxazole, ticarcillin-clavavulanic acid and fluoroquinolones are lower; especially, new fluoroquinolones have stronger antimicrobial activities. CONCLUSION: The rate of isolating Stenotrophomonas maltophilia strains from clinical samples has been rising. In the therapy of Stenotrophomonas maltophilia infection, trimethoprim-sulfamethoxazole or fluoroquinolones is empirically the medicine of choice. For the treatment of serious infection, the administration of trimethoprim-sulfamethoxazole combined with ticarcillin-clavavulanic acid or new fluoroquinolones is rational.