OBJECTIVEGroup A β-hemolytic streptococcus (GAS) or Streptococcus pyogenes may be encountered in diverse clinical situations in children. A rising incidence of invasive group A streptococcus (IGAS) infections has been noted in children in the past three decades. The aim of this study was to summarize the clinical characteristics and antimicrobial resistance of IGAS in children, and to raise the level of diagnosis and treatment of this infection.

METHODThe clinical data from 19 cases of IGAS younger than 14 years old seen from January 2004 to December 2011 treated in the authors' hospital were analyzed. IGAS infections are defined as the isolation of GAS from a normally sterile site in patients.

RESULTThe 19 cases were identified as IGAS infections, among whom 15 were male and 4 were female, and the ratio of them was 3.75. The age ranged from 1 day to 14 years, with a median age of 4 years. The course of disease was 4 h-10 days. The average length of stay was 12.2 days. In 13 cases the episodes of the infection occurred in winter and spring. In 18 cases the infection was community-acquired. Overall, 10 cases had neck or foot dorsum abscess, four cases had purulent peritonitis, and 3 cases were diagnosed as streptococcal toxic shock syndrome (STSS) complicated with empyema, pyopneumothorax occurred in 1 case and neonatal septicemia in another. Three cases had an underlying disease, including 2 cases wounded in a car accident and 1 case of congenital esophageal atresia and tracheoesophageal fistula. Before the isolation of GAS, 5 cases had stayed in ICUs, the length of ICU stay was 1-32 days, 4 cases had received intubation and mechanical ventilation, the ventilation time was 8 h-24 days, 2 cases had received major surgery; 5 cases had other pathogen coinfection, including 4 cases of abdominal pus at the same time and Escherichia coli was isolated, and 1 case had parainfluenza virus type I coinfection. Peripheral blood leucocyte increased in 18 cases, one case dropped off. The C-reactive protein (CRP) levels increased in all patients, including 16 cases who had 14-160 mg/L, 3 cases had levels higher than 160 mg/L. Twenty strains of GAS were isolated from 19 cases' sterile sites, of them 10 strains were isolated from abscess, 4 strains were isolated from blood and another 4 from ascites. Two strains were from the same patient at different times of pleural effusion. All 20 strains displayed a full susceptibility to cefazolin, levofloxacin and vancomycin, and the rates of resistance to both cefotaxime and penicillin were 10.0%. The rates of resistance to erythromycin and clindamycin were 55.0% and 70.0% respectively. Among the patients 3 cases were cured, 14 cases improved, and 2 cases died, of whom 1 case died of STSS secondary to multiple organ dysfunction, 1 case died of basic disease secondary to multiple organ dysfunction.

CONCLUSIONSkin and soft tissues were the most common IGAS infection sites in children, and IGAS infection also can lead to serious STSS and even can be life threatening. Penicillin and cephalosporin are still sensitive for children IGAS infections.

Abscess ; drug therapy ; epidemiology ; microbiology ; Adolescent ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Cephalosporins ; therapeutic use ; Child ; Child, Preschool ; Clindamycin ; therapeutic use ; Community-Acquired Infections ; drug therapy ; epidemiology ; microbiology ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Microbial Sensitivity Tests ; Retrospective Studies ; Soft Tissue Infections ; drug therapy ; epidemiology ; microbiology ; Streptococcal Infections ; drug therapy ; epidemiology ; microbiology ; Streptococcus pyogenes ; drug effects ; isolation & purification

OBJECTIVETo investigate the infection of hospital- and community-acquired "erythromycin-induced clindamycin resistant" strains or D-test positives of clinical isolates of Staphylococcus aureus (S. aureus) (with and without methicillin resistance) in a hospital.

METHODSStrains of S. aureus isolated from clinical specimens were subjected to D-test and antibiotic profiling.

RESULTSOf the total 278 isolates, 140 (50.35%) were D-test positives and the rest were D-test negatives. Further, of 140 (100%) positives, 87 (62.14%) and 53 (37.85%) strains were from males and females, respectively. Of 140 (100%) positives, 117 (83.57%) were methicillin resistant S. aureus and 23 (16.42%) were methicillin sensitive S. aureus; of 140 strains, 103 (73.57%) strains from persons with and 37 (26.42%) were without related infections; of 140 strains, 91 (65%) and 49 (35%) were from hospital- and community-acquired samples, respectively. In 140 strains, 118 (84.28%) with comorbidities and 22 (15.71%) without comorbidities cases were recorded; similarly, persons with prior antibiotic uses contributed 108 (77.14%) and without 32 (22.85%) positive strains. These binary data of surveillance were analyzed by a univariate analysis. It was evident that the prior antibiotic uses and comorbidities due to other ailments were the determinative factors in D-test positivity, corroborated by low P values, P=0.001 1 and 0.002 4, respectively. All isolates (278) were resistant to 17 antibiotics of nine groups, in varying degrees; the minimum of 28% resistance for vancomycin and the maximum of 97% resistance for gentamicin were recorded. Further, of 278 strains, only 42 (15.1%) strains were resistant constitutively to both antibiotics, erythromycin resistant and clindamycin resistant, while 45 (16.2%) strains were constitutively sensitive to both antibiotics (erythromycin sensitive and clindamycin sensitive). Further, of the rest 191 (68.7%) strains were with erythromycin resistant and clindamycin resistant, of which only 140 (50.35%) strains were D-test positives, while the rest 51 (18.34%) strains were D-test negatives.

CONCLUSIONSIn view of high prevalence of D-test positive S. aureus strains, and equally high prevalence of multidrug resistant strains both in community and hospital sectors, undertaking of D-test may be routinely conducted for suppurative infections.

Anti-Bacterial Agents ; pharmacology ; Clindamycin ; pharmacology ; Community-Acquired Infections ; epidemiology ; microbiology ; Cross Infection ; epidemiology ; microbiology ; Drug Resistance, Bacterial ; Erythromycin ; pharmacology ; Female ; Hospitals, Teaching ; Humans ; India ; epidemiology ; Male ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Staphylococcal Infections ; epidemiology ; microbiology ; Staphylococcus aureus ; drug effects ; isolation & purification

BACKGROUNDIncreasing prevalence of Staphylococcus aureus (S. aureus), particularly methicillin-resistant S. aureus (MRSA) has been reported in China. In this study, we investigated the drug resistance characteristic, genetic background, and molecular epidemiological characteristic of S. aureus in Changsha.

METHODSBetween January 2006 and December 2008, 293 clinical isolates of S. aureus were collected from 11 hospitals in Changsha and identified by the Vitek-2 system. All the isolates were verified as MRSA by PCR amplification of both femA and mecA genes. K-B disk method was used to test drug sensitivity of S. aureus to antibiotics. Pulsed-field gel electrophoresis (PFGE) was performed for genotypic and homologous analysis of 115 isolates randomly selected from the original 293 clinical S. aureus isolates.

RESULTSS. aureus was highly resistant to penicillin, ampicillin, erythromycin, and clindamycin with resistant rates of 96.6%, 96.6%, 77.1%, and 67.2% respectively. All the isolates were susceptible to tecoplanin, vancomycin, and linezolid. MRSA accounted for 64.8% (190/293) of all the S. aureus strains. The 115 S. aureus isolates were clustered into 39 PFGE types by PFGE typing, with 13 predominant patterns (designated types A to M) accounting for 89 isolates. The most prevalent PFGE type was type A (n = 56, 48.7%) and 100.0% of type A strains were MRSA. PFGE type A included 13 subtypes, and the most prevalent subtype was subtype A1 (46.4%, 26/56). Strains with PFGE type A were isolated from eight hospitals (8/11), and both subtypes A1 and A4 strains were isolated in a university hospital.

CONCLUSIONSClinical isolates of S. aureus in Changsha were resistant to multiple traditional antibiotics. There was an outbreak of PFGE type A MRSA in this area and the A1 subtype was the predominant epidemic clone. Dissemination of the same clone was an important reason for the wide spread of MRSA.

Ampicillin ; pharmacology ; Anti-Bacterial Agents ; pharmacology ; China ; Clindamycin ; pharmacology ; Electrophoresis, Gel, Pulsed-Field ; Erythromycin ; pharmacology ; Humans ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; genetics ; Microbial Sensitivity Tests ; Penicillins ; pharmacology ; Staphylococcus aureus ; drug effects ; genetics ; Vancomycin ; metabolism

OBJECTIVETo isolate and culture the predominant anaerobes from the periodontal abscesses, and to test the antibiotic susceptibility and drug resistant genes of the strains.

METHODSThe isolated strains were identified by both API20A biochemical method and polymerase chain reaction (PCR) method. The antibiotic susceptibility test was performed by agar dilution method. The resistant genes of the drug-resistant strains obtained were screened by PCR.

RESULTSThe anaerobes were detected in 48% (28/58) of the samples and Prevotella melaninogenica (Pm) was mostly identified in 43% (12/28). API20A biochemical method had 82% (23/28) agreement with the 16SrRNA method in identification rate. Anaerobes were resistant to metronidazole, clindamycin and cefmetazole. The erythromycin-resistant methylase genes F (ermF) gene was detected in three of eight clindamycin resistant strains. None of them was found coded on bacterial plasmids. However, no metronidazole resistant gene was detected on drug resistant strains.

CONCLUSIONSPm was the predominant species dectected in the periodontal abscess of the patients. The antibiotic agents should be used based on the genotypes and general condition of the patients.

Adult ; Anti-Bacterial Agents ; pharmacology ; Bacteria, Anaerobic ; isolation & purification ; Cefmetazole ; pharmacology ; Clindamycin ; pharmacology ; Drug Resistance, Bacterial ; genetics ; Erythromycin ; pharmacology ; Female ; Genes, Bacterial ; Humans ; Male ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Periodontal Abscess ; microbiology ; Prevotella ; isolation & purification

BACKGROUND: Susceptibility testing of Staphylococcus aureus often requires cumbersome supplementary tests. MicroScan Pos Breakpoint Combo Panel Type 28 (PBC28) (Siemens, USA) includes cefoxitin screening to detect methicillin-resistant Staphylococcus aureus (MRSA), inducible clindamycin resistance detection (ICD), and determination of low-range minimum inhibitory concentration of vancomycin (0.5-16 microgram/mL). The purpose of this study was to evaluate the performance of PBC28 in comparison with that of Pos Combo Type 1A (PC1A) (Siemens). METHODS: From December 2009 to March 2010, 500 non-duplicate clinical isolates of S. aureus were tested with PC1A and PBC28. Categorical agreements (CA) between the interpretations of the 2 panels were estimated. The presence of the mecA gene was determined by PCR, and double-disk diffusion test (D-test) was performed on the isolates resistant to erythromycin but susceptible or intermediately resistant to clindamycin. Ninety-six isolates representing various vancomycin minimum inhibitory concentrations (MICs) were tested in parallel with repeat PBC28, broth macrodilution, and epsilometer test (E test). RESULTS: The CA was 99.3% with a very major error (VME) of 0.2%, major error (ME) of 0.1%, and minor error (mE) of 0.4% in total. PBC28 showed 100% CA for 1 isolate with vancomycin MIC of 4 microgram/mL and 35 isolates (7.0%) with MIC of 2 microgram/mL. However, only 15, 27, and 35 isolates with vancomycin MIC of 2 microgram/mL showed 100% CA in repeat PBC28, broth macrodilution, and E test, respectively. PC1A and PBC28 detected all 314 mecA-positive isolates. Among the 63 isolates tested with the D-test, 58 (92.1%) were positive, and the results were 100% concordant with those of ICD. CONCLUSIONS: PBC28 can be appropriate susceptibility testing of S. aureus, including MRSA detection and ICD. However, the lower-range vancomycin MIC test was not reproducible enough to reliably differentiate MIC of 2 microgram/mL from MIC< or =1 microgram/mL.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; Cefoxitin/*pharmacology ; Clindamycin/*pharmacology ; Drug Resistance, Bacterial ; Methicillin-Resistant Staphylococcus aureus/genetics/isolation & purification ; *Microbial Sensitivity Tests ; Reagent Kits, Diagnostic ; Sensitivity and Specificity ; Staphylococcus aureus/*drug effects/genetics/isolation & purification ; Vancomycin/*pharmacology

BACKGROUND: Few studies have evaluated the performance of the recently introduced MicroScan Synergies plus Positive Combo 3 Panels (SIPC3) (Dade Behring Inc., USA). We evaluated the clinical efficacy of the panels in identification (ID) and antimicrobial susceptibility testing (AST) of Staphylococcusaureus and enterococci. METHODS: To evaluate the panels' accuracy of identification, the results obtained using the test panels were compared with those obtained by using conventional biochemical tests in conjunction with VITEK 2 system (bio-Merieux, USA). In addition, the AST results obtained using the panels were compared with those obtained by performing CLSI broth microdilution. RESULTS: The overall agreement between the approaches for the ID of S. aureus and enterococci was 100% and 96%, respectively. The categorical and essential agreements (CA and EA) for S. aureus were 98%, each. Very major errors (VME), major errors (ME), and minor error (mE) for S. aureus were 0.45%, 0.3%, and 4.2%, respectively. The majority of VMEs were for oxacillin (8.6%), penicillin (2.0%), erythromycin (7.9%), clindamycin (3.8%), and tetracycline (4.1%). For enterococci, the CA, EA, VME, ME, and mE were 88.8%, 93.7%, 4.4%, 0%, and 2.8%, respectively. The 80.5% (29/36) of Enterococcus faecium had concordant ID with the reference. Most of the categorical errors (3 VMEs and 14 mEs) were observed for quinupristin/dalfopristin (Synercid; Catalytica Pharmaceuticals Inc., USA). CONCLUSIONS: The panels compared favorably with conventional methods for the ID and AST of S. aureus. However, we expected a better performance for ID of E. faecium and AST using Synercid.
Anti-Bacterial Agents/*pharmacology ; Clindamycin/pharmacology ; Drug Resistance, Bacterial ; Enterococcus/*drug effects/isolation & purification ; Erythromycin/pharmacology ; Microbial Sensitivity Tests/instrumentation/*methods ; Oxacillin/pharmacology ; Penicillins/pharmacology ; Reagent Kits, Diagnostic ; Staphylococcus aureus/*drug effects/isolation & purification ; Tetracycline/pharmacology

BACKGROUND: Antimicrobial susceptibility of Legionella spp. has rarely been studied in Korea. Therefore, we aimed to determine the susceptibility of Legionella spp. to various antibiotics. METHODS: We assessed the antimicrobial susceptibility of 66 environmental and clinical Legionella isolates collected between January 2001 and December 2008 from Korea and Japan. The minimum inhibitory concentrations (MICs) of 6 antibiotics, namely, azithromycin, ciprofloxacin, clarithromycin, clindamycin, gatifloxacin, and gemifloxacin were determined by the broth microdilution method using buffered starch yeast extract broth. RESULTS: The MIC ranges of the 6 antibiotics used against the Legionella isolates were as follows: 0.004-0.062 microgram/mL (azithromycin), 0.002-0.5 microgram/mL (ciprofloxacin), 0.004-0.5 microgram/mL (clarithromycin), 0.12-4 microgram/mL (clindamycin), 0.002-0.12 microgram/mL (gatifloxacin), and 0.008-1 microgram/mL (gemifloxacin). CONCLUSIONS: Legionella spp. isolates from Korea and Japan were most susceptible to gatifloxacin. Azithromycin, clarithromycin, ciprofloxacin, and gemifloxacin were also effective for treating legionellosis.
Anti-Bacterial Agents/*pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; Clindamycin/pharmacology ; Drug Resistance, Bacterial ; Fluoroquinolones/pharmacology ; Humans ; Legionella/*drug effects/isolation & purification ; Legionellosis/diagnosis/microbiology ; Microbial Sensitivity Tests ; Naphthyridines/pharmacology

The aim of this study was to investigate antimicrobial susceptibilities and macrolide resistance mechanisms of beta-hemolytic viridans group streptococci (VGS) in a tertiary Korean hospital. Minimum inhibitory concentrations (MICs) of seven antimicrobials were determined for 103 beta-hemolytic VGS isolated from various specimens. The macrolide resistance mechanisms of erythromycin-resistant isolates were studied by the double disk test and polymerase chain reaction (PCR). The overall resistance rates of beta-hemolytic VGS were found to be 47.5% to tetracycline, 3.9% to chloramphenicol, 9.7% to erythromycin, and 6.8% to clindamycin, whereas all isolates were susceptible to penicillin G, ceftriaxone, and vancomycin. Among ten erythromycin-resistant isolates, six isolates expressed a constitutive MLSB (cMLSB) phenotype, and each of the two isolates expressed the M phenotype, and the inducible MLSB (iMLSB) phenotype. The resistance rates to erythromycin and clindamycin of beta-hemolytic VGS seemed to be lower than those of non-beta-hemolytic VGS in our hospital, although cMLSB phenotype carrying erm(B) was dominant in beta-hemolytic VGS.
Ceftriaxone/pharmacology ; Chloramphenicol/pharmacology ; Clindamycin/pharmacology ; Cross Infection/*genetics ; *Drug Resistance, Bacterial ; Erythromycin/pharmacology ; Humans ; Immunoenzyme Techniques ; Korea ; Macrolides/*pharmacology ; Penicillin G/pharmacology ; Phenotype ; Polymerase Chain Reaction ; Tetracycline/pharmacology ; Vancomycin/pharmacology ; Viridans Streptococci/*genetics/*metabolism

Clindamycin resistance in Staphylococcus species can be either constitutive or inducible. Inducible resistance cannot be detected by the conventional antimicrobial susceptibility test. In this study, we determined the prevalence of inducible clindamycin resistance in staphylococcal isolates at a Korean tertiary care hospital. Between February and September 2004, 1,519 isolates of Staphylococcus aureus and 1,043 isolates of coagulase-negative staphylococci (CNS) were tested for inducible resistance by the D-zone test. Overall, 17% of MRSA, 84% of MSSA, 37% of MRCNS, and 70% of MSCNS were susceptible to clindamycin. Of the erythromycin non-susceptible, clindamycin-susceptible isolates, 32% of MRSA, 35% of MSSA, 90% of MRCNS, and 94% of MSCNS had inducible clindamycin resistance. Inducible clindamycin resistance in staphylococci was highly prevalent in Korea. This study indicates importance of the D-zone test in detecting inducible clindamycin resistance in staphylococci to aid in the optimal treatment of patients.
Staphylococcus aureus/metabolism ; Staphylococcal Infections/*metabolism ; Prevalence ; *Microbial Sensitivity Tests ; Korea ; Humans ; Drug Resistance, Multiple, Bacterial ; *Drug Resistance, Microbial ; Clindamycin/*pharmacology ; Anti-Infective Agents/*pharmacology ; Anti-Bacterial Agents/*pharmacology

OBJECTIVETo investigate the prevalence and drug resistance of Streptococcus (S.) pneumoniae in patients infected in communities and molecular epidemiology with BOX-polymerase chain reaction (PCR) in Chongqing areas.

METHODSA total of 680 clinical specimens from sputum and throat/nasal swabs were collected from patients seen from September 2000 to March 2001. Antibiotic susceptibility was determined by agar dilution test. BOX-PCR was used for molecular typing of S. pneumoniae.

RESULTSA total of 39 isolates of S. pneumoniae were collected with the isolation rate of 5.7%. Of the 34 S. pneumoniae strains, two showed low-level resistance to penicillin (MIC 0.125 mg/L), one to levofloxacin, but many to macrolide and clindamycin (nearly 70%). All the strains were susceptible to beta-lactams and vancomycin. BOX-PCR typing demonstrated a high discriminatory potential and easy to be accurately analysed. 35 S. pneumoniae strains (include ATCC49619) were divided into 25 distinct types, representing 29 subtypes with A (n = 3) as the predominant type. 2 penicillin-resistant strains were shown to be different types.

CONCLUSIONPenicillin resistant rate of S. pneumoniae was low in Chongqing, but macrolide and clindamycin resistant strains were common while BOX-PCR typing was a suitable technique to type S. pneumoniae. No dominant antibiotic resistant strains were found in Chongqing.

China ; epidemiology ; Clindamycin ; pharmacology ; DNA, Bacterial ; genetics ; Drug Resistance, Bacterial ; genetics ; Humans ; Macrolides ; pharmacology ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Pneumococcal Infections ; epidemiology ; microbiology ; Prevalence ; Streptococcus pneumoniae ; drug effects ; genetics