OBJECTIVETo study the distribution and antibiotic resistance of the isolated pathogens from children with infectious diarrhea in Guangzhou.

METHODSThe fecal samples of 2 409 children with infectious diarrhea between January 2006 and December 2007 were collected and cultured. Pathogenic bacterium were isolated and identified by biochemical and serological methods. The antibiotic susceptibilities were tested by the Kirby-Bauer method.

RESULTSA total of 448 isolates of pathogenic bacterium (18.6%) were obtained, including Shigella (n=159), enteropathogenic Escherichia coli (n=141), Salmonella (n=76), Vibrion (n=11), fungus (n=41), and C jejuni (n=20). All of isolates of the three major pathogenic bacterium, Shigella, enteropathogenic Escherichia coli and Salmonella, were susceptible to imipenem and less than 10% of the isolates were resistant to the third generation cephalosporins and beta-lactamase inhibitors. However, the isolates showed a high resistance to ampicillin and sulfamethoxazole/trimethoprim (>75%).

CONCLUSIONSShigella, enteropathogenic Escherichia coli and Salmonella were major pathogenic bacterium of diarrhea in children from Guangzhou. The major isolates were susceptible to imipenem, the third generation cephalosporins and beta -lactamase inhibitors, but were resistant to ampicillin and sulfamethoxazole/trimethoprim.

Adolescent ; Bacteria ; drug effects ; isolation & purification ; Child ; Child, Preschool ; Diarrhea ; drug therapy ; microbiology ; Drug Resistance, Microbial ; Female ; Fungi ; drug effects ; isolation & purification ; Humans ; Infant ; Male

OBJECTIVETo investigate the antimicrobial resistance and penicillin resistance-associated genes (TEM and pbp2B) of Streptococcus pneumoniae (S. pneumoniae) isolated from sputum specimens of Guangzhou children with respiratory tract infection.

METHODSE-test and Kirby-Bauer methods were applied to detect the antibiotic susceptibility of 44 strains of S. pneumoniae. PCR was used to detect resistance genes pbp2B and TEM, followed by DNA sequence analysis of pbp2B gene. The sequence results were compared to those of penicillin-susceptible S. pneumoniae R6.

RESULTSOf the 44 isolates of S. pneumoniae, only 5 (11.4%) were susceptible to penicillin. All strains were resistant to erythromycin but susceptible to ofloxacin and vancomycin. The resistance rate of the isolates to clindamycin and trimoxazole was more than 90%. The S. pneumoniae isolates showed a high susceptibility to amoxicillin, imipenem and ceftriaxone, with a resistance rate of 0, 2.6% and 3.9%, respectively. The sequence analysis showed that more than 99% nucleotide sequence of pbp2B gene of five penicillin-susceptible isolates was the same as penicillin-susceptible S. pneumoniae R6, without any amino acid replacement. Site mutation was found in the remaining 39 penicillin-nonsusceptible isolates with a nucleotide mutation rate ranging from 13.2% to 23.1% and amino acid replacement rate from 6.5% to 10.9%. The 39 penicillin-nonsusceptible isolates were classified into 4 types according to the mutation site between Ser391 and Thr492 of pbp2B: type I (n=30), type II (n=7), type III (n=1) and type IV (n=1). No TEM gene was detected in all the 44 S. pneumoniae isolates.

CONCLUSIONSThe S.pneumoniae isolates from Guangzhou children with respiratory tract infection are resistant to penicillin and erythromycin. Amoxicillin and the third generation cephalosporin may be recommended for treating S. pneumoniae infection. The mutation of pbp2B gene plays an important role in the development of S. pneumoniae resistance to penicillin.

Aminoacyltransferases ; genetics ; Child, Preschool ; Drug Resistance, Bacterial ; genetics ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Penicillin Resistance ; genetics ; Penicillin-Binding Proteins ; genetics ; Respiratory Tract Infections ; microbiology ; Streptococcus pneumoniae ; drug effects ; genetics ; beta-Lactamases ; genetics

OBJECTIVETo investigate the situation of antibiotic resistance of Streptococcus pneumoniae (Sp) and Hemophilus influenzae (Hi) clinical isolates from children in Guangzhou area.

METHODSThe authors cultured, isolated and identified the Sp and Hi strains from nasopharyngeal secretion of patients who visited Guangzhou Children's Hospital for upper respiratory tract infection between 2003 and 2004. K-B disc diffusion and E-test for antibiotic susceptibility were performed for these clinical isolates.

RESULTSTotally 172 and 484 strains of Sp and Hi were respectively isolated from nasopharyngeal secretions in the hospital. For Sp strains, the rates of resistance to penicillin, amoxicillin/clavulanic acid, ceftriaxone, cefuroxime, cefaclor, erythromycin, tetracycline, chloramphenicol, sulfamethoxazole/trimethoprim (SMZ/TMP), clindamycin and ofloxacin were 32.0%, 11.1%, 32.6%, 18.1%, 39.5%, 82.6%, 78.5%, 24.4%, 87.2%, 69.2% and 3.1%, respectively. The penicillin non-susceptible Sp (PNSSP) isolates showed higher rates of resistance to other antimicrobial agents such as other beta-lactam antimicrobial agents, erythromycin, and SMZ/TMP than those of penicillin susceptible Sp (PSSP) isolates. More than 90% of PNSSP were multidrug resistant strains. The average rate of beta-lactamase production among 484 strains of Hi was 29.5% (143/484). For Hi isolates, the rates of resistance to ampicillin, amoxicillin/clavulanic acid, ceftriaxone, cefuroxime, cefaclor, SMZ/TMP, tetracycline, chloramphenicol, azithromycin, and ofloxacin were 40.1%, 3.4%, 4.1%, 1.9%, 5.6%, 56.2%, 52.1%, 17.4%, 2.1%, and 0.6%, respectively.

CONCLUSIONThe antimicrobials resistant Sp and Hi isolated from children with respiratory tract infection in the area have become a severe problem. The rate of resistance to penicillin of Sp had been decreased compared with the last three years, but the rate of resistance to ceftriaxone of Sp increased, and the multidrug resistance rates of PNSSP was rather high. PNSSP was characterized by a multidrug-resistance to erythromycin, tetracycline and SMZ/TMP. beta-lactamase production and ampicillin resistance among the Hi isolates from children in the area had increased generally during the period 2003 - 2004. The Hi isolates were more susceptible to the second and the third generation cephalosporins, amoxicillin/clavulanic acid and azithromycin.

Anti-Bacterial Agents ; pharmacology ; Child, Preschool ; China ; Drug Resistance, Bacterial ; Female ; Haemophilus Infections ; drug therapy ; microbiology ; Haemophilus influenzae ; drug effects ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Male ; Microbial Sensitivity Tests ; Nasopharynx ; microbiology ; Pneumonia, Pneumococcal ; drug therapy ; microbiology ; Respiratory Tract Infections ; drug therapy ; microbiology ; Streptococcus pneumoniae ; drug effects ; isolation & purification

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal recessive disorder. This paper reports three cases of SSADH deficiency in infants. The infants developed the symptoms including developmental delay, intellectual disability, hypotonia, hyporeflexia and seizures. The electroencephalogram (EEG) showed background slowing and focal spike discharges in all of 3 patients. Head magnetic resonance imaging (MRI) demonstrated abnormalities in 2 patients, including basal ganglia damage and increased T2-weighted signal in bilateral cerebral peduncles. Urinary organic acid analysis with gas chromatography-mass spectrometry (GC-MS) revealed increased levels of 4-hydroxybutyrate (GHB) in 3 patients. SSADH deficiency was definitely diagnosed based on the clinical manifestations and the results of urinary organic acid analysis in the 3 children. It was concluded that early urine organic acid analysis is essential for children presenting with mental retardation, neuropsychiatric disturbance or epilepsy of unknown etiology.
Amino Acid Metabolism, Inborn Errors ; diagnosis ; therapy ; Developmental Disabilities ; Diagnosis, Differential ; Female ; Humans ; Infant ; Succinate-Semialdehyde Dehydrogenase ; deficiency

Ongoing study on the chemical constituents of the roots of Macleaya microcarpa led to the isolation of eight compounds of derivatives of triterpenes and organic acids in addition to some previously identified benzophenanthridines. The eight compounds were identified by spectroscopic methods as well as comparison with literature values as 1-oxo-2, 22 (30)-hopandien-29-oic acid (1), 3-oxo-12-oleanen-30-oic acid (2), 3α-hydroxy-12-oleanen-30-oic acid (3), 3β-hydroxy-12-oleanen-30-oic acid (4), ferulic acid (5), ferulic acid 4-O-β-D-glucoside (6), 3-O-feruloylquinic acid (7), and methyl 3-O-feruloylquinate (8). Of which, 1 is a new triterpenoid of hopanes and 2-8 are isolated from M microcarpa for the first time. In order to discover natural active compounds as potential agents of anti-ulcerative colitis (UC), an in vitro drug high-throughput screening model targeted x-box-binding protein 1 (xbp1) was employed to evaluate the activity of the major chemical constituents of M microcarpa. The result confirmed that two dihydrobenzophenanthridines, dihydrosanguinarine (9) and dihydrochelerythrine (10), showed a certain activity on activating the transcription of xbpl, a transcription factor (TF) associated with the occurrence, development, and potential treatment of UC, with their relative activating ratios being 1.76 and 1.77 times, respectively, as compared with control group.
Anti-Ulcer Agents ; chemistry ; Benzophenanthridines ; chemistry ; DNA-Binding Proteins ; genetics ; Isoquinolines ; chemistry ; Papaveraceae ; chemistry ; Plant Roots ; chemistry ; Regulatory Factor X Transcription Factors ; Transcription Factors ; genetics ; Transcription, Genetic ; Triterpenes ; chemistry

Taking application of some isolation and purification technologies, including crushing, solvent extraction, preliminary solvent isolation, column chromatographies over silica gel and Sephadex LH-20 gel and preparative HPLC, 8 compounds were obtained from the seeds of Jufeng grape sourced from market. Their structures were identified by spectroscopic methods and comparison with literature values as Catechin (1), Epicatechin (2), quercetin (3), ethylgallate (4), rel-(2S, 3R) -2-(4-hydroxy-3-methoxyphenyl) -3- (hydroxymethyl)-5-(3-hydroxypropyl)-2,3-dihydrobenzofuran-7-ol (5), rel-(2α, 3β)-7-O-methylcedrusin (6), rel-(1R,2S)-1-(4-hydroxy-3-methoxyphenyl) -2-(4-(3-hydroxypropyl) -2-methoxyphenoxy) propane-1,3-diol (7), and (+) -isolariciresinol (8), respectively. Compounds 5-8 were serial lignans isolated from the seeds of grape for the first time. Structurally, 5 and 6 belong in benzofuran-8,3'-neolignans, 7 in 8,4'-oxyneolignan, and 8 in 8,8' :2,7'-cyclolignan. According to in vitro activity evaluation conducted in cell model, compound 6 showed significant anti-oxidative ability, with the activity of RAW264. 7 cell superoxide dismutase being raised evidently in the test as compared with the positive anti-oxidative agents, compounds 1 and 2.
Antioxidants ; chemistry ; isolation & purification ; Magnetic Resonance Spectroscopy ; Plant Extracts ; chemistry ; isolation & purification ; Seeds ; chemistry ; Vitis ; chemistry

OBJECTIVETo investigate the incidence of campylobacter jejuni (CJ) infection and the drug resistance of CJ in children with diarrhea in Guangzhou.

METHODSThe fecal samples of 3,351 children with diarrhea between July 2005 and June 2008 were collected for CJ culture. The species of CJ strains were identified by Lior methods. The drug susceptibility tests were performed by the Kirby-Bauer method.

RESULTSTwo hundred and sixty-seven CJ strains (8.0%) were isolated from 3,351 samples. The children at age of 1 month to 1 year were susceptible to CJ, accounting for 91.0%. A higher incidence of CJ infection (76.8%) was found in summer and autumn. The CJ strains were susceptible to imipenem, amikacin, cefoperazone/sulbactam, chloramphenicol, macrolides and lincomycins. Parts of CJ strains (20%-40%) were resistant to ampicillin, quinolones and ambramycin. All CJ strains were resistant to sulfamethoxazole/trimethoprim and cefditoren. Two hundred and one strains (75.3%) were CJ biotype I.

CONCLUSIONSCJ is an important pathogen of diarrhea in children from Guangzhou. CJ is resistant to some antibiotics used often in clinical practice, and so it is thus important to use antibiotics based on the results of drug susceptibility tests in children with CJ infection.

Campylobacter Infections ; microbiology ; Campylobacter jejuni ; classification ; drug effects ; isolation & purification ; Child, Preschool ; Diarrhea ; microbiology ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests

OBJECTIVETo study the influence of lipopolysaccharide (LPS) on the permeability of rat brain microvascular endothelial cells (BMECs) and possible molecular mechanism.

METHODSMonolayers of primary rat BMECs were separated and cultured, and then treated with (LPS group) or without LPS (control group). The barrier integrity was measured by transendothelial electrical resistance (TEER) assay. The degrees of RhoA activation were determined by Pull-down assay. The expression levels of p115RhoGEF, zonula occludens-1 (ZO-1), occludin and claudin-5 proteins were detected by Western blot analysis.

RESULTSThe average TEER values of rat BMECs in the LPS group were 108.3±4.2 Ω•cm2 and 85.4±2.5 Ω•cm2 respectively 3 and 12 hrs after LPS treatment, which were significantly lower than that in the control group (159.0±8.6 Ω•cm2). Compared with the control group, the activity of RhoA started to increase 5 minutes after LPS treatment, and the expression of p115RhoGEF protein started to increase 1 hr after LPS treatment and the cellular protein levels of ZO-1, occludin and claudin-5 decreased significantly 3 hrs after LPS treatment in the LPS group (P<0.05).

CONCLUSIONSLPS may activate the p115RhoGEF/RhoA pathway and decrease protein expression of ZO-1, occludin and claudin-5, resulting in an increased permeability of rat BMECs.

Animals ; Brain ; blood supply ; Capillary Permeability ; drug effects ; Electric Impedance ; Endothelial Cells ; drug effects ; metabolism ; Guanine Nucleotide Exchange Factors ; analysis ; Lipopolysaccharides ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Rho Guanine Nucleotide Exchange Factors ; Tight Junctions ; chemistry ; rhoA GTP-Binding Protein ; analysis

OBJECTIVETo clone UreB gene of Helicobacter pylori (H. pylori) isolated from children to pGEX-4T-1 expression plasmid, and do sequence analysis.

METHODSA pair of specific primer was designed according to H. pylori UreB gene in the GenBank. Using H. pylori strains isolated from children as a template, a UreB gene was obtained by PCR. After EcoR I and Not I digestion, the PCR production was linked with pGEX-4T-1 which was digested with the same enzymes. The recombinant plasmid was transformed into E.coli BL21 and identified by double enzyme digestion and sequence analysis. The sequence results were compared with the gene sequence in the GenBank.

RESULTSA UreB gene was successfully amplified from children's H. pylori strain GZCH1. It was 1710 bp in size. The objective band was identified by double enzyme digestion. DNA sequence showed that UreB was in the correct open reading frame. The sequence comparison analysis showed that DNA and amino acid sequence identities of UreB gene with other strains were 98%. The sequence of UreB of H. pylori strain GZCH1 was submitted to GenBank (accession number:FJ455126).

CONCLUSIONSUreB of H. pylori strain GZCH1 is successfully cloned to pGEX-4T-1, which provides a basis for research of oral H. pylori vaccine.

Amino Acid Sequence ; Bacterial Vaccines ; immunology ; Child ; Cloning, Molecular ; Helicobacter pylori ; enzymology ; immunology ; Humans ; Male ; Molecular Sequence Data ; Urease ; chemistry ; genetics ; immunology

Objective To study the electric shock protection requirements of in vitro diagnostic equipment and to help manufacturers understand the relevant requirements in order to design products reasonably. Methods The requirements of IEC 61010-1:2010 were analyzed, the electric shock protection measures were explored, and the principles for protecting ground impedance against electric shock were described. An example was taken to study the electric shock protection measures for the sampling needle of the automatic bio-chemical analyzer, so that the existence of electric shock hazard could be determined. Results The sampling needle proved its rationality in structure design by avoiding the risk for being electriferous in case of failed basic insulation, although the requirements for protective earthing, double insulation or reinforced insulation were not met efficiently. Conclusion The requirements for electric shock protection can be determined based on comprehensive understanding of the standard, determination of electriferous components of the equipment as well as analysis on electric shock protection measures.