OBJECTIVETo investigate the basic clinical characteristics and drug resistance of Haemophilus influenzae (Hi) infection in hospitalized children in the past two years.

METHODSA retrospective cross-sectional study was conducted to analyze Hi strains isolated from the sputum and pharyngeal swabs of children aged 0-17 years who were hospitalized in the Third People's Hospital of Chengdu between June 2011 and May 2013.

RESULTSA total of 117 strains were isolated from 111 hospitalized children. There were 102 cases (91.9%) of respiratory infection and 9 cases (8.1%) of other diseases. The positive rates of Hi in children with bronchopneumonia or pneumonia (50.8%, 30/59) and in children with acute laryngotracheobronchitis (50.0%, 2/4) were relatively high, followed by in children with capillary bronchitis (34.6%, 9/26), in children with acute bronchitis (24.2%, 32/132), in children with herpangina (19.0%, 4/21), in children with asthmatoid bronchitis (17.9%, 5/28), in children with acute upper respiratory tract infection (11.8%, 9/76), in children with acute tonsillitis (8.2%, 7/85), and in children with neonatal pneumonia (5.6%, 3/54). There were significant differences in the rates of resistance to amoxicillin-clavulanate (15% vs 23%; P=0.010) and chloramphenicol (25% vs 8%; P=0.015) between the two survey years. The frequencice of β-lactamase-nonproducing-ampicillin-resistant (BLNAR) strains and β-lactamase-producing-amoxicilli/clavulanate-resistant (BLPACR) strains increased from 12% to 21% and from 13% to 19% respectively during the two survey years (P>0.05).

CONCLUSIONSHi plays an important role in the respiratory tract infection of children aged 0-17 years. The increasing trend of BLNAR and BLPACR rates makes it harder for antibiotic selection in clinical practice.

Adolescent ; Amoxicillin-Potassium Clavulanate Combination ; pharmacology ; Child ; Child, Hospitalized ; Child, Preschool ; Cross-Sectional Studies ; Drug Resistance, Bacterial ; Haemophilus influenzae ; drug effects ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Retrospective Studies

OBJECTIVE: To establish a biofilm model of Haemophilus influenzae and observe the effect of ambroxol on biofilm of Haemophilus influenzae and bactericidal action. METHOD: Thirty strains of Haemophilus influenzae were isolated from adenoids of children with adenoidal hypertrophy. Two strains which could build stronger biofilms was selected in a 96-well plate. The effect of ambroxol on biofilms were determined by crystal violet, and the structure of biofilms were observed by scanning electron microscope (SEM). The numbers of viable bacterial in biofilm after ambroxol treatmented determined by plate culture count. RESULT: Through crystal violet assay, significant difference (P < 0.01) between the two group after treatment was found when ambroxol concentration reached at 0.25 mg/ml and 0.49 mg/ml. The biofilms was destroyed by SEM. Ambroxol had the positive effect on bacterial killing by plate culture count,and the effect was in a dose dependent. CONCLUSION Ambroxol could destroy the biofilm of Haemophilus influenzae, and had bactericidal function in vitro.
Ambroxol ; pharmacology ; Biofilms ; drug effects ; Child ; Child, Preschool ; Haemophilus influenzae ; drug effects ; Humans ; Microbial Sensitivity Tests

OBJECTIVEThis research was to explore the difference between children with community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) in the composition and antibiotic-resistance of pathogenic bacteria.

METHODS241 CAP and 116 HAP with positive sputum culture who were hospitalized from January to December in 2008 in Children's Hospital Affiliated to Suzhou University were selected in this study. The bacteria were identified by traditionally manual method and antibiotic sensitivity tests were performed by K-B method. The chi-square or Fisher's exact test were used for statistical test.

RESULTSIn 241 CAP, Streptococcus pneumoniae and haemophilus influenza accounted for (42.2%, 106/251) and (12.4%, 31/251) infection, respectively; however in 116 HAP, Enterobacteriaceae and Non-fermenters accounted for (88.2%, 127/144). In addition, methicillin-resistant Staphylococcus aureus weren't isolated, however, its detection rate was 66.7% in HAP. The drug resistance was 1.5 times higher in HAP than that in CAP for several types of antibiotics, such as ceftazidime (37.5% (6/16) vs 75.6% (31/41)), cefepime (37.5% (6/16) vs 78.0% (32/41)), aztreonam (50.0% (8/16) vs 90.2% (37/41)), cefoperazone/sulbactam (12.5% (2/16) vs 51.2% (21/41)) and piperacillin/tazobactam (12.5% (2/16) vs 56.0% (23/41)). Klebsiella pneumoniae isolated from HAP had higher drug resistance than that isolated from CAP against some antibiotics, for example, gentamicin (0 vs 63.6% (7/11)), SMZ + TMP (20.0% (1/5) vs 63.6% (7/11)) and cefoperazone/sulbactam (0 vs 54.5% (6/11)). We also found Enterobacter cloacae isolated from HAP showed high drug resistance than that isolated from CAP against imipenem (0 vs 46.7% (7/15)), aztreonam (9.1% (1/11) vs 60.0% (9/15)) and cefoperazone (18.2% (2/11) vs 80.0% (12/15)) and Pseudomonas aeruginosa from HAP had higher resistance than that from CAP against gentamicin (0 vs 50.0% (9/18)), amikacin (0 vs 38.9% (7/18)), ceftazidime (0 vs 55.6% (10/18)), cefepime (0 vs 50.0% (9/18)) and cefoperazone (33.3% (2/6) vs 94.4% (17/18)). The detection rates of ESBLs for Escherichia coli were 84.6% (11/13) and 93.3% (14/15) in CAP and HAP, respectively (χ(2) = 0.553, P > 0.05); while for Klebsiella pneumoniae, they were 81.3% (13/16) and 95.1% (39/41), respectively (χ(2) = 2.767, P > 0.05).

CONCLUSIONCAP was mainly comprised of Streptococcus pneumoniae and haemophilus influenza; while HAP was mainly comprised of Enterobacteriaceae and Non-fermenters. The drug resistance of gram-negative bacilli was higher in HAP than that in CAP.

Child ; Child, Preschool ; Community-Acquired Infections ; microbiology ; Cross Infection ; microbiology ; Drug Resistance, Bacterial ; Female ; Gram-Negative Bacteria ; drug effects ; isolation & purification ; Haemophilus influenzae ; drug effects ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Male ; Microbial Sensitivity Tests ; Pneumonia, Bacterial ; microbiology ; Pseudomonas aeruginosa ; drug effects ; isolation & purification

Among 155 clinical respiratory isolates of Haemophilus influenzae in Korea, 6 (3.9%) isolates had reduced levofloxacin susceptibility (MICs > or = 0.5 microg/mL). These six isolates had no significant quinolone resistance-determining region (QRDR) mutations in gyrA, gyrB, parC, or parE. This phenomenon suggests that neither evolution nor spread of any significant QRDRs mutations in clinical isolates occurred in Korea. Therefore, continued surveillance is necessary to observe the evolution of antibiotic-resistance and take measures to avoid the spread of drug-resistant clones.
Anti-Bacterial Agents/*pharmacology ; DNA Gyrase/*genetics ; DNA Topoisomerases, Type II/*genetics ; Haemophilus influenzae/*drug effects/pathogenicity ; Korea ; Microbial Sensitivity Tests ; Mutation ; Ofloxacin/*pharmacology

Among 155 clinical respiratory isolates of Haemophilus influenzae in Korea, 6 (3.9%) isolates had reduced levofloxacin susceptibility (MICs > or = 0.5 microg/mL). These six isolates had no significant quinolone resistance-determining region (QRDR) mutations in gyrA, gyrB, parC, or parE. This phenomenon suggests that neither evolution nor spread of any significant QRDRs mutations in clinical isolates occurred in Korea. Therefore, continued surveillance is necessary to observe the evolution of antibiotic-resistance and take measures to avoid the spread of drug-resistant clones.
Anti-Bacterial Agents/*pharmacology ; DNA Gyrase/*genetics ; DNA Topoisomerases, Type II/*genetics ; Haemophilus influenzae/*drug effects/pathogenicity ; Korea ; Microbial Sensitivity Tests ; Mutation ; Ofloxacin/*pharmacology

OBJECTIVE: To investigate the pathogenic bacteria distribution and drug susceptibility in children with acute otitis media (AOM) in different age and different season in the Pearl River Delta region. METHOD: Four hundred and forty-two children diagnosed as AOM were divided into three groups by age factor and four groups by season factor. Midge ear pus collecting and culturing were used for bacteria and antimicrobial susceptibility test. RESULT: (1) Strains of bacteria were isolated from 356 children with the positive rate of 80.5%. Streptococcus pneumoniae (39.2%), staphylococcus aureus (25.9%) and haemophilus influenzae (7.4%) were the most frequently isolated pathogens. (2) Streptococcus pneumoniae was the main pathogenic bacteria in 0-1 year group and > 1-3 years group (P < 0.05), staphylococcus aureus was the most frequently isolated pathogen in >3 years group (P < 0.05); (3) In the season groups, the number of children with AOM decreased significantly in July-September group. There was no significant difference of streptococcus pneumoniae distribution among the four groups (P > 0.05). Staphylococcus aureus was the main pathogen in January-March group (P < 0.05); (4) Drug sensitivity shown that linezolid and ofloxacin were most sensitive to streptococcus pneumoniae and staphylococcus aureus, and macrolides had a good therapy effect to haemophilus influenzae. CONCLUSION The pathogens distribution and drug susceptibility in children with AOM were varies in different age and different season. As a result, a treatment should be done based on the climate, environment, and pathogens distribution of a region.
Adolescent ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Haemophilus influenzae ; drug effects ; isolation & purification ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Otitis Media ; drug therapy ; epidemiology ; microbiology ; Seasons ; Staphylococcus aureus ; drug effects ; isolation & purification ; Streptococcus pneumoniae ; drug effects ; isolation & purification

OBJECTIVETo investigate the serotypes distribution and ampicillin resistance of Haemophilus influenzae isolates from children with respiratory infection in Hangzhou.

METHODSHaemophilus influenzae strains were identified with V factor and X factor tests. Serotypes were determined with the slide agglutination method. Nitrocefin test was used to detect beta-lactamase. The sensitivities of ampicillin to Haemophilus influenzae were determined with the Kirby-Bauer diffusion method and the E-test method.

RESULTSOne hundred and fifty-two Haemophilus influenzae isolates, 108 from boys and 44 from girls, were identified between December 2006 and July 2007. Of the 152 isolates, 148 (97.4%) were untypable, only 4 (2.6%) were typable, including type a, type d, type e and type f (n=1 each type). Haemophilus influenzae type b and c strain was not found. Thirty-four isolates (22.4%) were beta-lactamase-positive. One hundred and thirteen isolates (74.3%) were susceptible to ampicillin, while 34 isolates (22.4%) were resistant to ampicillin.

CONCLUSIONSUntypable strains were the most common in Haemophilus influenzae isolates from children with respiratory infection in Hangzhou. The isolates of Haemophilus influenzae kept susceptibity to ampicillin to a certain extent.

Adolescent ; Ampicillin Resistance ; Child ; Child, Preschool ; Female ; Haemophilus influenzae ; classification ; drug effects ; enzymology ; Humans ; Infant ; Infant, Newborn ; Male ; Microbial Sensitivity Tests ; Respiratory Tract Infections ; microbiology ; Serotyping ; beta-Lactamases ; analysis

Child ; China ; Community-Acquired Infections ; microbiology ; Drug Resistance, Bacterial ; genetics ; Haemophilus influenzae type b ; drug effects ; genetics ; isolation & purification ; Humans ; Microbial Sensitivity Tests ; Pneumonia ; microbiology

BACKGROUNDIt is recognized that Haemophilus influenzae isolated from patients with otitis media forms biofilms both in vitro and in vivo, suggesting that biofilm formation in vivo might play an important role in the pathogenesis and chronicity of otitis media, but the effect of antibiotics on biofilm has not been well studied. We investigated the impact of ciprofloxacin and azithromycin on bacterial biofilms formed by Haemophilus influenzae in vitro in this study.

METHODSEleven strains of Haemophilus influenzae were isolated from sputum specimens collected from patients with acute exacerbation of chronic obstructive pulmonary diseases. Formation of bacterial biofilm was examined by crystal violet assay and a scanning electron microscope. Alterations of biofilms were measured under varying concentrations of azithromycin and ciprofloxacin.

RESULTSStriking differences were observed among strains with regard to the ability to form biofilm. Typical membrane-like structure formed by bacterial cells and extracellular matrix was detected. Initial biofilm synthesis was inhibited by azithromycin and ciprofloxacin at concentrations higher than two-fold minimal inhibitory concentration. Disruption of mature biofilms could be achieved at relatively higher concentration, and ciprofloxacin displayed more powerful activity.

CONCLUSIONSHaemophilus influenzae is capable of forming biofilm in vitro. Sufficient dosage might control early formation of biofilms. Ciprofloxacin exerts better effects on breakdown of biofilm than azithromycin at conventional concentration in clinics.

Anti-Bacterial Agents ; pharmacology ; Azithromycin ; pharmacology ; Biofilms ; drug effects ; Ciprofloxacin ; pharmacology ; Haemophilus influenzae ; drug effects ; isolation & purification ; Humans ; Lung Diseases, Obstructive ; microbiology ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning

The in vitro antibacterial activities of oral cephem antibiotics and ketolide telithromycin against major respiratory pathogens possessing beta-lactam-resistant mutations (within the pbp gene) and/or macrolide-resistant genes (erm and mef) were examined in clinical isolates collected at 66 institutes in all over the Japan between 2002 and 2003. Telithromycin showed the strongest antibacterial activity against methicillinsusceptible Staphylococcus aureus strains with and without macrolide-resistant genes, such as ermA or ermC gene. All the cephem antibiotics showed potent antibacterial activity against Streptococcus pyogenes, with minimum inhibitory concentrations (MICs) of 0.015 mg/L or lower. Cefdinir had a much higher MIC90 against genotypic penicillin-resistant Streptococcus pneumoniae (gPRSP) than cefditoren and cefcapene (8 mg/L cefdinir vs. 1 mg/L cefditoren and cefcapene). The majority of gPRSP harbored either ermB or mefA, and the antibacterial activity of telithromycin against these strains was decreased however some susceptibility was still sustained. Cefditoren exerted the strongest antibacterial activity against beta-lactamase-negative ampicillin-resistant Haemophilus influenzae, with an MIC90 of 0.5 mg/L. These results underline the importance of checking the susceptibility and selecting an appropriate antibiotic against target pathogens.
Streptococcus pyogenes/*drug effects ; Streptococcus pneumoniae/*drug effects ; Staphylococcus aureus/*drug effects ; Microbial Sensitivity Tests ; Methicillin Resistance ; Ketolides/*pharmacology ; Humans ; Haemophilus influenzae/*drug effects ; Cephalosporins/*pharmacology ; Administration, Oral