Emergence and spread of O16-ST131 and O25b-ST131 clones among faecal CTX-M-producing Escherichia coli in healthy individuals in Hunan Province, China.

OBJECTIVES: The objectives of this study were to determine CTX-M-producing Escherichia coli ST131 strain prevalence in stool specimens from healthy subjects in central China and to molecularly characterize clonal groups. METHODS: From November 2013 to January 2014, stool specimens from healthy individuals in Hunan Province were screened for ESBL-producing E. coli using chromogenic medium and CTX-M genotypes and phylogenetic groups were determined. ST131 clonal groups were detected by PCR and characterized for antibiotic resistance, fimH, gyrA and parC alleles, plasmid-mediated quinolone resistance determinants, virulence genotypes and PFGE patterns. RESULTS: Among 563 subjects, 287 (51.0%) exhibited the presence of faecal ESBL-producing E. coli, all of which produced CTX-M enzymes. The most common CTX-M genotypes were CTX-M-14 (48.4%), CTX-M-15 (27.5%) and CTX-M-27 (15.0%). Of the 287 CTX-M-producing isolates, 32 (11.1%) belonged to the ST131 clone. O16-ST131 isolates were dominant (75%) and contained the fimH41 allele. The remaining eight (25%) ST131 isolates were of the O25b subgroup and contained fimH30 or fimH41. Ciprofloxacin resistance was found in 100% of the O25b-ST131 isolates, whereas only 8% of the O16-ST131 isolates were resistant. All of the O25b-ST131 isolates except one showed gyrA1AB and parC1aAB mutations; most of the O16-ST131 isolates had gyrA1A and parC1b mutations. The virulence genotypes of O16-ST131 resembled those of the O25b-ST131 isolates. The 32 ST131 isolates formed one large group at the 64% similarity level. They comprised 15 PFGE groups (defined at ≥85% similarity). CONCLUSIONS: O16-ST131 isolates have emerged as the predominant type of ST131 isolate in faecal CTX-M-producing E. coli in healthy individuals in China.

Community Fecal Carriage and Molecular Epidemiology of Extended-Spectrum ß-Lactamase- and Carbapenemase-Producing Escherichia coli from Healthy Children in the Central South China.

Background: Fecal carriage of extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) and carbapenemase-producing E. coli (CP-EC) is well reported among hospitalized adults and children. However, there are few studies on the carriage prevalence and ESBL-EC and CP-EC genotypes among healthy children in China. Patients and Methods: Stool samples were collected from 330 students in 2021 from three randomly selected primary schools in Changsha, China. ESBL-EC and CP-EC were screened using CHROMagarTM chromogenic plates. ESBL and carbapenemase production was confirmed using the double-disc synergy test and a modified carbapenem inactivation method, respectively. Antimicrobial susceptibility was tested using the broth microdilution method. Resistance determinants, virulence factors, and phylogenetic groups were determined by PCR and sequencing. Multi-locus sequence typing (MLST) was performed (seven housekeeping genes were amplified and sequenced) on the phylogenic group B2 E. coli to detect high-risk clonal strains such as ST131 E. coli. Then, ST131 E. coli were characterized based on ST131 clades, O-type, and fimH alleles. Results: In total, 118 (35.8%) ESBL-EC and 3 (0.9%) CP-EC were isolated. bla CTX-M was the most common genotype (27.1%), identified in all ESBL-EC, except one, which carried bla SHV-12. One isolate with mcr-1 was found amongst ESBL-EC, whereas all three CP-EC carried bla NDM-1. The predominant sequence type (ST) clones in group B2 were ST131 and ST1193. The prevalence of ST131 E. coli was 9.9%, displaying serotypes O16 and O25b, fimH alleles 30, 41, and 89, and ST131 clades A and C1-M27. Conclusion: In this study, high carriage rate of ESBL-EC was found among healthy children, and the dominant ESBL was CTX-M-14. In addition, high-risk clones (ST131 and ST1193) were also detected. This emphasizes the importance of monitoring ESBL-EC in community settings.

Evaluation of our self-designed nanometer silicon membrane sandwich cup system for diagnosing tuberculosis.

BACKGROUND AND AIMS: A nanometer silicon membrane sandwich cup system was self-designed. It could concentrate the bacilli via 0.45-µm microporous filter membrane and semi-automate the acid-fast bacilli (AFB) by a bacteria-staining machine. The aim of the study was to assess the clinical value of our self-designed system for diagnosing tuberculosis (TB). METHODS: A total of 1993 sputum specimens obtained from patients with confirmed or suspected TB were subjected to direct or concentrated specimens smear at XiangYa Hospital, Central South University between May 2012 and February 2013. In addition, all the specimens were also inoculated into Lowenstein-Jensen (L-J) media, and culture results were considered as the gold standard for calculating sensitivity and specificity. RESULTS: Compared with direct smear examination, an increased density of red stained bacilli was observed in the self-designed nanometer silicon membrane sandwich cup analysis under the microscope. The positive rate of the self-designed analysis was significantly higher than that of direct AFB smear [10.9% (217/1993) vs 6.2% (123/1993), P < 0.05]. The sensitivity of the self-designed system increased (97.3% vs 55.2%, P < 0.05) without a loss of specificity (100% vs 100%) for identifying positive TB cases compared with the direct smear method. CONCLUSION: The self-designed nanometer silicon membrane sandwich cup and semi-automatic bacteria-staining machine could more efficiently and rapidly detect the AFB in respiratory specimens than direct microscopy. This is a novel and safe examination, and it may replace direct smear examination for the diagnosis of patients with TB.

[Effect of yiqijiedu granule on the implanted-tumor protein expression in nasopharyngeal carcinoma].

OBJECTIVE: To investigate the inhibitory mechanism of Yiqijiedu granule on the implanted-tumor growth of nasopharyngeal carcinoma in nude mice. METHODS: Twenty nude mice were injected nasopharyngeal carcinoma cells (HNE1), with 5 x 10(6) cells for a nude mouse. Implanted-tumors grew for 20 d, whose volume reached 1 cm x 1 cm x 1 cm. These nude mice were divided into 2 groups: Yiqijiedu group and control group. The Yiqijiedu group was given Yiqijiedu granule, and the control was given normal saline for 30 d, and then were killed. The volume and weight of implanted-tumors were measured. A 100-mg tissue from implanted-tumors was used to extract total protein by current methods, in which the proteins were separated by two-dimension electrophoresis and stained by silver, and protein profiles of implanted-tumors were obtained. Different proteins in the profiles were analyzed by ImageMaster 2D Elite 4.01. Nineteen different proteins, in which 4 expressed in the Yiqijiedu group, 4 expressed in the control, and the other 11 were differently expressed at 5 folds, were identified by MALDI-TOF-MS. RESULTS: The Yiqijiedu granule could inhibit the growth of implanted-tumors. The volume and weight of implanted-tumors in the Yiqijiedu group were (0.207 +/- 0.023) cm3 and (0.132 +/- 0.021) g respectively, and that of the control was (1.342 +/- 0.298) cm3 and (1.017 +/- 0.015) g ( P < 0.05). The inhibitory rate was 84.58%. The analyses of two-dimension electrophoresis and ImageMaster 2D Elite 4.01 showed that there were 567 +/- 49 protein dots in the Yiqijiedu group and 679 +/- 59 in the control. We found 243 proteins were dys-regulated, of which 112 proteins were observed, up-regulated and the other 131 proteins were down-regulated. MALDI-TOF-MS and Database analysis showed that the high expression proteins were HKR2 protein, 10 Phosphoribosyl pyrophosphate synthetase, TNFR superfamily member, and Apoptosis regulator. The lower expression proteins were Fibulin-3, Zinc finger protein 266, Carboxy terminus of HSP70-interacting protein, et al. CONCLUSION: Yiqijiedu granule could inhibit the growth of nasopharyngeal carcinoma, which may be associated with those proteins regulated by itself.

[Value of simultaneous determination of serum hyaluronic acid, collagen type IV and the laminin level in diagnosing liver fibrosis].

OBJECTIVE: To study the value of simultaneous determination of serum hyaluronic acid(HA), collagen Type IV (CIV) and the laminin (LN) level in the diagnosis of liver fibrosis. METHODS: Serum HA, CIV and LN were measured by ELISA in 22 healthy persons, 10 cases of acute hepatitis, 10 cases of chronic hepatitis, 10 cases of heary chronic hepatitis, and another 25 cases of posthepatitic cirrhosis. The sensitivity, specificity and accuracy of simultaneous determination were compared with those of single determination in posthepatitic cirrhosis. RESULTS: The levels of serum HA, CIV and LN in posthepatitic cirrhosis cases and heary chronic hepatitis cases were significantly higher than those in the other groups (P < 0.01). Simultaneous determination of these indices enhanced the diagnostic sensitivity, but decreased the diagnostic specificity. CONCLUSION: Simultaneous determination of HA, CIV and LN can enhance the diagnostic sensitivity. Simultaneous determination of HA and CIV is an optimal choice.

[Antibiotic susceptibility of Neisseria gonorrhoeae epidemic strains in Changsha].

OBJECTIVE: To evaluate the antibiotic susceptibility of Neisseria gonorrhoeae epidemic strains in Changsha and to provide a reference for the prevention and treatment of gonorrhea. METHODS: beta-Lactamase was determined by a modified iodometric method and the susceptibility to 9 antibiotic agents was tested by the disc diffusion method in 86 isolates. RESULTS: Plasmid-mediated penicillinase-producing Neisseria gonorrhoeae and plasmid-mediated tetracycline-resistant Neisseria gonorrhoeae were 40.69% and 23.26%, respectively. Of all the 9 antibiotic agents, tetracycline, cefmetazole, penicillin, ciprofloxacin, and ofloxacin had a higher resistance and the percentages of resistance were 45.35%, 50.00%, 62.79%, 77.91%, and 87.21%, respectively. On the other hand, cefuroxime, ceftriaxone, cefepime, and spectinomycin had a higher susceptibility and the percentages of susceptibility were 77.91%, 80.23%, 86.05%, and 98.84%, respectively. CONCLUSION: Penicillin, tetracycline and fluoroquinolone can not be used as routine agents to cure gonorrhea; and spectinomycin can be used as primary medicine to cure gonorrhea in Changsha, but clinical doctors need to pay more attention to it because resistant strains have come into existence.

[Detection of serum sialic acid in three kinds of malignant tumor and its clinical significance].

OBJECTIVE: To study the diagnostic significance and clinical effect of the detection of serum sialic acid (SA) in three kinds of malignant tumor. METHODS: The specimens (172) were divided into the healthy control group (100), lung cancer group (31), leukemia group (28) and rectual cancer group (17), and then the serum SA concentration in those specimens was analyzed and statistic analysis was conducted. RESULTS: The SA levels of the malignant tumor groups before and after the treatment were significantly higher than those of the healthy control group (P < 0.05). The positive rates of serum SA in the lung cancer group, leukemia group and rectual group were 84%, 79% and 71%. CONCLUSION: The SA concentration was significantly increased in the malignant patients so SA can be used as an indication of cancer, and it can be widely used in the diagnosis and inspection of malignant tumor.