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

Aerococcus viridans, a catalase-negative gram-positive coccus rarely causing bacteremia, was isolated from blood cultures of a 52-yr-old man under the gran-ulocytopenic condition. The isolate showed the typical characteristics of A. viridans, i.e., tetrad arrangements in gram stain, positive pyrrolidonyl aminopeptidase (PYR) and negative leucine aminopeptidase (LAP) reactions, and no growth at 45 degrees C.The isolate was revealed to be highly resistant to penicillin, erythromycin, clindamycin, and ceftriaxone, although most strains of A. viridans isolated from the previously reported patients were susceptible to penicillin and other commonly used antibiotics. Even though A. viridans is rarely associated with human infections, it could be a potential causative agent of bacteremia, especially in immunocompromised patients.
Agranulocytosis/*complications/microbiology/physiopathology ; Bacteremia/*complications/microbiology/physiopathology ; Ceftriaxone/pharmacology ; Clindamycin/pharmacology ; *Drug Resistance, Multiple, Bacterial ; Erythromycin/pharmacology ; Gram-Positive Bacterial Infections/*complications/microbiology/physiopathology ; Humans ; Male ; Middle Aged ; Penicillins/*pharmacology ; Streptococcaceae/*drug effects/isolation & purification

In order to identify ceftriaxone and its analogs whether has the function of anti-tolerance of morphine and study the dose-effect relation of ceftriaxone in mice, hot plate method to measure pain threshold of mouse and naloxone withdrawal models were carried out and compared with normal saline group. Ceftriaxone and cefotaxime had the effect of anti-tolerance and anti-dependence of morphine notably. And ceftriaxone has the effect of anti-tolerance of morphine in a dose dependent manner.
Animals ; Anti-Bacterial Agents ; pharmacology ; Cefotaxime ; pharmacology ; Ceftriaxone ; pharmacology ; Dose-Response Relationship, Drug ; Drug Tolerance ; Female ; Mice ; Morphine ; pharmacology ; Morphine Dependence ; prevention & control ; Pain Threshold ; drug effects ; Random Allocation ; Substance Withdrawal Syndrome ; physiopathology

OBJECTIVETo investigate the effect of β-lactam antibiotics ceftriaxone on the levels of glutamate in hippocampus following traumatic brain injury in rat.

METHODSRats were divided randomly into three groups:sham group; trauma group and trauma+ceftriaxone group. Rats in the later two groups were subjected to a lateral cortical impact injury caused by a free-falling object, and trauma+ceftriaxone group was treated with ceftriaxone immediately after injury. The levels of glutamate in hippocampus was determined by HPLC at 12 h after trauma; the pathological change at 24 h after trauma was examined and water content of brain tissue at 3, 12 and 24 h after trauma was measured in three groups.

RESULTSCompared with the trauma group,the water content in brain tissue (P<0.05), neuronal death in hippocampus CAl area and the levels of glutamate and aspartate in hippocampus at 12 h (P<0.05) were significantly decreased in trauma+ceftriaxone group.

CONCLUSIONβ-lactam antibiotics ceftriaxone can reduce the level of brain glutamate, brain edema and neuronal death after traumatic brain injury in rat.

Animals ; Brain Injuries ; metabolism ; pathology ; Ceftriaxone ; pharmacology ; Disease Models, Animal ; Female ; Glutamic Acid ; metabolism ; Hippocampus ; drug effects ; metabolism ; pathology ; Male ; Rats ; Rats, Sprague-Dawley

Though the pathogenic significance and the reservoir of Ewingella americana have not been clarified, this organism has caused several pathogenic infections, especially in immunocompromised patients. We report a pneumonia in a patient with chronic renal failure, who had chronic rejection of transplanted kidney. E. americana was identified to be the pathogen of pneumonia with clinical symptoms and signs and radiological examination. As soon as he was treated with ceftriaxone and isepamicin, clinical improvement was followed with no further growth of E. americana or other pathogenic isolates from sputum culture. This suggests to be the case of pneumonia caused by E. americana for the first time in the Korean literature.
Adult ; Anti-Bacterial Agents/pharmacology ; Ceftriaxone/pharmacology ; Enterobacteriaceae/*metabolism ; Enterobacteriaceae Infections/*complications ; Gentamicins/pharmacology ; Humans ; Kidney Failure, Chronic/*complications/*microbiology ; Kidney Transplantation ; Male ; Pneumonia/complications/*microbiology ; Sputum/metabolism ; Time Factors

OBJECTIVETo observe the influence of borneol, a traditional Chinese medicine, on the concentration of ceftriaxone in the rat brain striatum and evaluate the relativity.

METHODThe sample of cerebrospinal fluid in the rat brain striatum was collected via brain microdialysis technology, and then the contents of ceftriaxone in standard preparation and sample were detected by high efficiency liquid chromatography combined with diode array detector respectively and analyzed statistically. The concentration of ceftriaxone in rat brain striatum in the ceftriaxone + Borneol group was compared with that in the ceftriaxone-only group.

RESULTThe concentration of ceftriaxone in the rat brain in the ceftriaxone + Borneol group (13.01-4.43 mg x L(-1)) is significantly higher than that in the ceftriaxone-only group (2.41-0.94 mg x L(-1)).

CONCLUSIONBorneol can promote ceftriaxone through blood-brain barrier, and increase the concentration thereof in striatum.

2-Pyridinylmethylsulfinylbenzimidazoles ; pharmacokinetics ; Animals ; Blood-Brain Barrier ; Bornanes ; pharmacology ; Ceftriaxone ; pharmacology ; Chromatography, High Pressure Liquid ; Corpus Striatum ; drug effects ; metabolism ; Drug Combinations ; Male ; Medicine, Chinese Traditional ; Microdialysis ; Neostriatum ; drug effects ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo investigate the effect of ceftriaxone on the intestinal epithelium and microbiota in mice in the early-life stage, as well as the recovery of the intestinal epithelium and reconstruction of intestinal microbiota in adult mice.

METHODSA total of 36 BALB/C neonatal mice were randomly divided into control group and experimental group, with 18 mice in each group. The mice in the experimental group were given ceftriaxone 100 mg/kg every day by gavage within 21 days after birth. Those in the control group were given an equal volume of normal saline by gavage. Immunohistochemistry was used to measure the expression of Ki67, Muc2, and ZO-1 in the intestinal epithelium. qPCR and next-generation sequencing were used to analyze the overall concentration and composition of fecal bacteria.

RESULTSAfter 21 days of ceftriaxone intervention, the experimental group had a significant reduction in body weight, a significant reduction in the expression of Ki67 and ZO-1 and a significant increase in the expression of Muc2 in intestinal epithelial cells, a significant reduction in the overall concentration of fecal bacteria, and a significant increase in the diversity of fecal bacteria compared with the control group (P<0.05). Firmicutes was the most common type of fecal bacteria in the experimental group, and there were large amounts of Staphylococcus and Enterococcus. The experimental group had a certain degree of recovery of the intestinal epithelium, but there were still significant differences in body weight and the structure of intestinal microbiota between the two groups at 56 days after birth (P<0.05).

CONCLUSIONSEarly ceftriaxone intervention significantly affects the development of the intestinal epithelium and the construction of intestinal microbiota in the early-life stage. The injury of the intestinal microbiota in the early-life stage may continue to the adult stage and affect growth and development and physiological metabolism.

Animals ; Animals, Newborn ; Anti-Bacterial Agents ; pharmacology ; Ceftriaxone ; pharmacology ; Female ; Gastrointestinal Microbiome ; drug effects ; Intestinal Mucosa ; drug effects ; Ki-67 Antigen ; analysis ; Mice ; Mice, Inbred BALB C ; Mucin-2 ; analysis ; Zonula Occludens-1 Protein ; analysis

OBJECTIVETo investigate the genotype and characteristics of Neisseria gonorrhoeae (N.gonorrhoeae) isolates with reduced susceptibility to ceftriaxone in Shenzhen from 2009 to 2011.

METHODSA total of 296 N.gonorrhoeae isolates were collected in Shenzhen from 2009 to 2011.ceftriaxone strains (minimum inhibitory concentration between 0.06 and 0.50 µg/ml) were determined by agar dilution method.Logistic regression was used to analyze the associated factors of ceftriaxone N.gonorrhoeae infection.Neighbor-joining (NJ) phylogenetic tree analysis and N.gonorrhoeae multi antigen sequence typing (NG-MAST) were performed on all ceftriaxone isolates and susceptible control isolates randomly selected in accordance with the principle of 1: 1 sampling.

RESULTSNo isolates displayed resistance to ceftriaxone, whereas 53(17.9%) showed reduced susceptibility to ceftriaxone among 296 isolates.Only antibiotic use in recent two months was associated with ceftriaxone isolates infection (OR = 3.080, 95%CI: 1.376-6.894) . Among the ceftriaxone isolates, 48 different ST were identified including 5 STs (ST1768, ST3927, ST641, ST7076 and ST7078) containing 2 isolates and 43 single STs. There were 26 STs previously reported from HongKong in China.Low sensitive strains clustering was not observed by NJ phylogenetic tree.

CONCLUSIONThe proportion of ceftriaxone strains among the 296 N.gonorrhoeae isolates collected from 2009 to 2011 in Shenzhen is high. The STs of ceftriaxone strains may have unique epidemic features in Shenzhen.

Adult ; Anti-Bacterial Agents ; pharmacology ; Ceftriaxone ; pharmacology ; China ; epidemiology ; Drug Resistance, Bacterial ; genetics ; Female ; Gonorrhea ; epidemiology ; microbiology ; Humans ; Male ; Middle Aged ; Molecular Epidemiology ; Neisseria gonorrhoeae ; classification ; drug effects ; genetics ; isolation & purification ; Young Adult

OBJECTIVETo study the resistance of staphylococcus aureus (S. aureus) isolated from children in Hangzhou to antibiotics and analyze the clinical value of mecA-PCR in determining oxacillin-resistant isolates.

METHODSS. aureus isolates were screened by using latex agglutination test and identified with GPI card of Vitek system. Antibiotics sensitivity tests were performed using disk diffusion methods and tests for sensitivity to oxacillin and vancomycin were performed with a further E-test method. The mecA gene was detected with polymerase-chain reaction (PCR).

RESULTSOf all 259 S. aureus strains, 185 from clinical specimens in inpatients and 74 from pharyngeal swabs in healthy children, 247 strains (95.8%) were beta-lactamase-positive and resistant to penicillin, while 91.1% of all strains were sensitive to oxacillin. All the strains were sensitive to vacomycin and 91.9% of all the strains were susceptible to cefotaxime and ceftriaxone. Resistance to erythromycin, tetracycline, clindamycin, trimethoprim-sulfamethoxazole, chloramphenicol, ofloxacin and rifampin were 48.3%, 30.9%, 21.6%, 11.2%, 10.0%, 2.3% and 1.5%, respectively. The resistance rate to oxacillin, cefotaxime, and ceftriaxone in clinical strains were significantly higher than that in carried strains (P < 0.05), while erythromycin-resistance rate was significantly higher in carried strains than that in clinical isolates (P < 0.05). The mecA-PCR showed that the control strain ATCC25923 and all oxacillin-sensitive S. aureus were mecA-negative, while all oxacillin-resistant strains were mecA-positive instead. Only one strain was mecA-positive in 7 oxacillin-intermediate S. aureus strains.

CONCLUSIONOxacillin-resistance in S. aureus isolates was low, and mecA-PCR method is a good choice for rapid examination oxacillin-resistant strains.

Anti-Bacterial Agents ; pharmacology ; Bacterial Proteins ; genetics ; isolation & purification ; Cefotaxime ; pharmacology ; Ceftriaxone ; pharmacology ; Child ; Child, Preschool ; China ; Drug Resistance, Bacterial ; genetics ; Erythromycin ; pharmacology ; Humans ; Latex Fixation Tests ; Methicillin Resistance ; genetics ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; Microbial Sensitivity Tests ; Oxacillin ; pharmacology ; Penicillin-Binding Proteins ; Penicillins ; pharmacology ; Polymerase Chain Reaction ; Staphylococcal Infections ; drug therapy ; microbiology ; Staphylococcus aureus ; drug effects ; genetics ; isolation & purification ; Vancomycin ; pharmacology

PURPOSE: The detection of high-level tetracycline-resistant strains of Neisseria gonorrhoeae (TRNG) can make important epidemiological contributions that are relevant to controlling infections from this pathogen. In this study, we aimed to determine the incidence of TRNG isolates over time and also to investigate the characteristics and genetic epidemiology of these TRNG isolates in Korea. MATERIALS AND METHODS: The antimicrobial susceptibilities of 601 isolates of N. gonorrhoeae from 2004 to 2011 were tested by standard Clinical and Laboratory Standards Institute methods. To determine the molecular epidemiological relatedness, N. gonorrhoeae multi-antigen sequence typing was performed. RESULTS: The incidence of TRNG increased from 2% in 2004 to 21% in 2011. The minimum inhibitory concentration distributions of ceftriaxone and susceptibility of ciprofloxacin in TRNG were different from non-TRNG and varied according to the year of isolation. Most of the TRNG isolates collected from 2004 to 2007 exhibited genetic relatedness, with sequence type (ST) 1798 being the most common. From 2008 to 2011, the STs of the isolates became more variable and introduction of genetically unrelated TRNG were noted. CONCLUSION: The increased incidence of TRNG strains until 2007 appears to be due, at least in part, to clonal spread. However, we propose that the emergence of various STs since 2008 could be associated with foreign import.
Anti-Bacterial Agents/*pharmacology ; Ceftriaxone/pharmacology ; Ciprofloxacin/pharmacology ; DNA, Bacterial/analysis ; Drug Resistance, Multiple, Bacterial/*genetics ; Gonorrhea/drug therapy/epidemiology/microbiology ; Humans ; Incidence ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Neisseria gonorrhoeae/*drug effects/*genetics/isolation & purification ; Republic of Korea/epidemiology ; Sequence Analysis, DNA ; Tetracycline/pharmacology ; Tetracyclines/*pharmacology