BACKGROUND: We determined the epidemiological characteristics of erythromycin (EM)-resistant Streptococcus pyogenes (group A streptococci, GAS) strains isolated from Korea and Japan, using emm genotyping and multilocus sequence typing (MLST). METHODS: Clinical isolates of GAS had been collected from 1992 to 2012 in Korea and from 2004 to 2009 in Japan. EM resistance was determined by the microdilution method, and resistance genotypes were assessed by PCR. The emm genotyping and MLST were performed by DNA sequencing. RESULTS: The emm genotypes and sequence types (STs) were concordant in 143 (85.1%) of 168 EM-resistant GAS strains from Korea. ST36/emm12 (35.1%), ST52/emm28 (22.6%), and ST49/emm75 (16.1%) were the most common types. Most of the ST36 (93.9%) and ST52 (95.8%) strains harbored erm(B), whereas strains ST49, ST42, and ST15 contained mef(A). The concordance between emm genotypes and STs was 41 (93.2%) among 44 EM-resistant GAS strains from Japan. ST36/emm12 (34.1%), ST49/emm75 (18.2%), and ST28/emm1 (15.9%) were the major types. ST36 isolates harbored either erm(B) (56.3%) or mef(A) (37.5%), whereas isolates ST28, ST49, and ST38 carried only mef(A). The proportion of erm(B) and mef(A) was 66.1% and 33.3% in Korea and 22.7% and 68.2% in Japan, respectively. CONCLUSIONS: The common STs in Korea and Japan were ST36 and ST49, whereas ST52 was present only in Korea and ST28 only in Japan. Genotype erm(B) was predominant in Korea, whereas mef(A) was frequent in Japan. There were differences between Korea and Japan regarding the frequencies of emm genotypes, STs, and EM resistance genes among the EM-resistant GAS.
Anti-Bacterial Agents/*pharmacology/therapeutic use ; Bacterial Proteins/*genetics ; Bacterial Typing Techniques ; *Drug Resistance, Bacterial ; Epidemiologic Studies ; Erythromycin/*pharmacology/therapeutic use ; Genotype ; Humans ; Japan/epidemiology ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Republic of Korea/epidemiology ; Streptococcal Infections/drug therapy/*microbiology ; Streptococcus pyogenes/drug effects/*genetics/isolation & purification

BACKGROUND: The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide. METHODS: We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics. RESULTS: Antibiotic susceptibility tests revealed that 100% and 47% isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84%) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16%) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes. CONCLUSIONS: The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; DNA, Bacterial/metabolism ; Drug Resistance, Multiple, Bacterial/*genetics ; Erythromycin/*pharmacology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Phenotype ; Pneumococcal Infections/microbiology/pathology ; Polymerase Chain Reaction ; Streptococcus pneumoniae/*drug effects/*genetics/isolation & purification ; Tetracycline/pharmacology

BACKGROUNDErythromycin-resistant Streptococcus pneumoniae isolates that causing invasive pneumococcal diseases (IPD) in Chinese children remain uncharacterized. This study aims to identify the resistance genes associated with erythromycin resistance and to determine the genetic relationships of IPD isolates in Chinese children.

METHODSA total of 171 S. pneumoniae strains were isolated from 11 medical centers in China from 2006 to 2008. All the isolates were characterized via serotyping and antibiotic susceptibility determination. The erythromycin-resistant isolates were further characterized via ermB and mefA gene detection, multi-locus sequence typing analysis, and pulsed-field gel electrophoresis.

RESULTSA total of 164 (95.9%) isolates showed resistance to erythromycin, of which 162 strains with high high-level resistance (MIC ≥ 256 µg/ml). A total of 104 (63.4%) isolates carry the ermB gene alone, whereas 59 (36.0%) harbor both ermB and mefA genes. Of the 59 strains, 54 were of serotypes 19A and 19F and were identified as highly clonal and related to the Taiwan(19F)-14 clone.

CONCLUSIONSThe erythromycin resistance rate in IPD isolates is significantly high and is predominantly mediated by the ermB gene. Isolates that carry both ermB and mefA genes are predominantly of serotypes 19A and 19F.

Adolescent ; Anti-Bacterial Agents ; pharmacology ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Erythromycin ; pharmacology ; Humans ; Infant ; Multilocus Sequence Typing ; Pneumococcal Infections ; microbiology ; Serotyping ; Streptococcus pneumoniae ; classification ; drug effects ; genetics ; isolation & purification

OBJECTIVETo observe the effect of the combination of sub-MIC sodium houttuyfonate and erythromycin on biofilm of Staphylococcus epidermidis.

METHODThe serial dilution method was adopted to determine MIC of the combination of sodium houttuyfonate and erythromycin on S. epidermidis; the checkerboard method was used to evaluate the combination of sodium houttuyfonate and erythromycin on suspended bacteria of S. epidermidis; S. epidermidis biofilm was built in vitro, and XTT reduction assay was used to evaluate the effect of the combination of sub-MIC sodium houttuyfonate and erythromycin on the adhesion of S. epidermidis and bacterial metabolism inside the biofilm. Microscope was applied to observe the impact the single administration and combination of the two medicines under sub-MIC on biofilm morphology of S. epidermidis.

RESULTThe MIC of sodium houttuyfonate and erythromycin were 62.5, 7.812 5 mg x L(-1), respectively. The combination of 1/8MIC sodium houttuyfonate and 1/2MIC erythronmycin showed a synergistic effect on S. epidermidis. Sodium houttuyfonate, erythromycin and their combination had an inhibitory effect on the adhesion and metabolism of S. epidermidis biofilm bacteria, and made impact on the morphology of S. epidermidis biofilm.

CONCLUSIONThe sub-MIC sodium houttuyfonate and erythromycin have an inhibitory effect on S. epidermidis biofilm. The combination of sodium houttuyfonate and erythromycin shows a synergistic effect in inhibiting suspended bacteria and biofilm of S. epidermidis, particularly in inhibiting the metabolism of S. epidermidis biofilm bacteria and impacting the morphology of biofilm.

Alkanes ; pharmacology ; Anti-Bacterial Agents ; pharmacology ; Bacterial Adhesion ; drug effects ; Biofilms ; drug effects ; growth & development ; Dose-Response Relationship, Drug ; Drug Interactions ; Erythromycin ; pharmacology ; Microbial Sensitivity Tests ; Staphylococcus epidermidis ; drug effects ; physiology ; Sulfites ; pharmacology

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

BACKGROUNDThe catheter related infection caused by Staphylococcus epidermidis biofilm is increasing and difficult to treat by antimicrobial chemotherapy. The properties of biofilms that give rise to antibiotic resistance are only partially understood. This study aimed to elucidate the penetration of erythromycin through Staphylococcus epidermidis biofilm.

METHODSThe penetration ratio of erythromycin through Staphylococcus epidermidis biofilms of 1457, 1457-msrA, and wild isolate S68 was detected by biofilm penetration model at different time points according to the standard regression curve. The RNA/DNA ratio and the cell density within the biofilms were observed by confocal laser microscope and transmission electromicroscope, respectively.

RESULTSThe penetration ratios of erythromycin through the biofilms of 1457, 1457-msrA, and S68 after cultivation for 36 hours were 0.93, 0.55 and 0.4, respectively. The erythromycin penetration ratio through 1457 biofilm (0.58 after 8 hours) was higher than that through the other two (0.499 and 0.31 after 24 hours). Lower growth rate of the cells in biofilm was shown, with reduction of RNA/DNA proportion observed by confocal laser microscope through acridine orange stain. Compared with the control group observed by transmission electrmicroscope, the cell density of biofilm air face was lower than that of agar face, with more cell debris.

CONCLUSIONSErythromycin could penetrate to the Staphylococcus epidermidis biofilm, but could not kill the cells thoroughly. The lower growth rate of the cells within biofilm could help decreasing the erythromycin susceptibility.

Acridine Orange ; Anti-Bacterial Agents ; pharmacokinetics ; Biofilms ; DNA, Bacterial ; analysis ; Erythromycin ; pharmacokinetics ; pharmacology ; Microscopy, Electron, Transmission ; RNA, Bacterial ; analysis ; Staphylococcus epidermidis ; drug effects ; metabolism

OBJECTIVETo investigate the effect of erythromycin on electrical activity and emptying of the intrathoracic stomach after esophagectomy for esophageal cancer.

METHODSThirty patients undergoing esophagectomy for cancer and esophagogastrostomy above the aortic arch were divided into the study group (n=15) and the control group (n=15). Electrogastrography and radionuclide gastric emptying were examined for these patients before and 1, 3, 6, 12 months after surgery. Patients in the study group received erythromycin (0.25 g tid po) for 1 week before examination.

RESULTSThe wave amplitude (Uv), dominant frequency (CPM) and percentage of normal slow wave (%) of electrogastrogram decreased after surgery and returned to normal at the first postoperative month in the study group and the 12th postoperative month in the control group (P>0.05). Gastric emptying was significantly delayed after esophagectomy, and returned to normal one year after operation in the study group (P>0.05). However, gastric emptying remained abnormal in the control group (P<0.01).

CONCLUSIONSErythromycin improves electrical activity and emptying of the stomach after esophagectomy for cancer. Gastric emptying recovery later than the recovery of electrical activity, which may be related to gastric ischemia and edema.

Adult ; Aged ; Erythromycin ; pharmacology ; Esophageal Neoplasms ; physiopathology ; surgery ; Female ; Gastric Emptying ; drug effects ; Humans ; Male ; Middle Aged ; Postoperative Period ; Stomach ; drug effects ; physiopathology

OBJECTIVETo provide a new therapeutic approach for Staphylococcus epidermidis biofilm-associated infections by the study of inhibitory effect of andrographolide (AG) on S. epidermidis biofilm.

METHODS. epidermidis biofilms were set up in vitro, erythromycin was acted as the positive control agent, XTT reduction assay was used to evaluate AG on the initial adhesion of S. epidermidis and bacterial metabolism within biofilm, microscope was applied to observe biofilm morphology, and Congo red assay was used to detect polysacchatide interc-ellular adhesion (PIA)formation when exposed to AG.

RESULTAG showed inhibitory effects against the initial adhesion of S. epidermidis at concentrations of 1 000,100, 10 mg x L(-1), respectively,and inhibited metabolism of biofilm bacteria at the concentration of 31.25 mg x L(-1), and exhibited significantly inhibition against the biofilm morphology at the concentration of 250 mg x L(-1), while did not display inhibition against PIA formation at the concentration of 10 mg x L(-1).

CONCLUSIONAG could remarkably inhibit biofilm formation of S. epidermidis, although it was less potent than erythromycin.

Bacterial Adhesion ; drug effects ; Biofilms ; drug effects ; Diterpenes ; pharmacology ; Dose-Response Relationship, Drug ; Erythromycin ; pharmacology ; Staphylococcus epidermidis ; drug effects ; physiology

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