• Journal of Pharmaceutical Investigation
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• v.17 no.3
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• pp.135-139
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• 1987

This study was attempted to investigate the dissolution rate and the bioavailability of commercially available sulfamethoxazole and trimethoprim (SMX-TM) tablets in rabbits. The dissolution test was conducted in artificial gastric juice by basket method with eight SMX-TM tablets which were chemically equivalent. According to the dissolution rate, SMX-TM tablets were divided into four groups, such as rapid, intermediate, slow and very slow groups for the bioavailability test in rabbits. The results were as follows: 1) The dissolution rate of brand A was most rapid but brand H was most slow in artificial gastric juice. 2) Area under the blood concentration curve was larger in the order of brand A > C > E > H in rabbits. 3) There was a little difference in pharmacokinetic parameters such as biological half life, absorption rate constant and $t_{max}$. 4) The relationship between the dissolution rate and relative bioavailability was significant in brand A, C, E and H. From the results of this experiment, the bioavailability of SMX-TM tablets in rabbits may be predicted from the results of dissolution rate studies.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.84-90
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• 2015

Seventeen ampicillin-sensitive coagulase-negative staphylococci (CNS) isolates identified in jeotgal were subjected to assessments for antibiotic susceptibility and safety hazards. Fifteen of the 17 CNS strains exhibited phenotypic resistances to at least one antibiotic, and their prevailing resistance was to penicillin G. The dfrA gene for trimethoprim and tetK for tetracycline were amplified by PCR from the two strains, respectively. α-Hemolytic activity was not detected from the 17 strains, while five strains presented δ-hemolytic activity. Among the five strains, two strains exhibited β-hemolytic activity. Biofilm was formed from twelve strains. All of the tested phenotypic characteristics were expressed in a strain-specific manner.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.1008-1013
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• 2014

The use of antimicrobial agents for additives or therapeutics is strongly associated with a prevalence of antimicrobial resistance in commensal Enterobacteriaceae. We aimed to characterize integrons in Enterobacteriaceae isolates obtained from chicken cecums in Korea. Moreover, the correlation between integron gene cassettes and antimicrobial resistance was also investigated. A total of 90 isolates the belonged to Enterobacteriaceae were recovered from chickens grown at Gyeongsang and Chungcheong provinces in Korea. Antimicrobial susceptibility tests were performed by the disk diffusion method. PCR and DNA sequencing were also performed to characterize the gene cassette arrays of the integrons. Of the 90 Enterobacteriaceae isolates tested, 39 (43.3%) and 10 (11.1%) isolates carried class 1 and 2 integrons, respectively. Whereas the class 2 integron did not contain gene cassettes, the class 1 integrons carried seven different gene cassette arrays. The class 1 integrons harbored genes encoding resistant determinants to aminoglycosides (aadA1, aadA2, and aadA5), trimethoprim (dfrA1, dfrA12, dfrA17, and dfrA32), lincosamides (linF), and erythromycin (ereA). Moreover, the presence of a class 1 integron was significantly related to a high resistance rate of antimicrobial agents, such as spectinomycin and trimethoprim. We confirmed that diverse class 1 integrons were widely distributed in Enterobacteriaceae isolates from chickens and directly contributed to the resistance to diverse antimicrobial agents in Korea.

• Parasites, Hosts and Diseases
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• v.27 no.2
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• pp.101-108
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• 1989

This study was performed to observe the role of Pneumocystis carinii as an etiologic agent of interstitial pneumonia in immunocompromised hosts. Total 90 male Sprague-Dawley rats, approxi. mately 150-180 g, were used. Fifteen of them were used as control group and remaining 75 (5 groups) were as immunosuppression groups; group 1 received prednisolone (25 mg/kg twice weekly) only; group 2 Prednisolone and tetracycline (75 mk/kg/day) ; group 3 Prednisolone, tetracycline and trimethoprim-sulfamethoxasole (50~250 mg/kg/day) : group 4 prednisolone and trimethoprim-sulfamethoxasole; and group 5 prednisolone and griseofulvin (300 mg/kg/day) until death. The survival days of each group rat were calculated, and upon death their lungs were removed immediately and then stamp smears were prepared and stained by Giemsa or toluidine blue O. For histopathologic observation, lungs were fixed in 10% formalin, cut into sections and stained with Gomori's methenamine silvei, hematoxylin-rosin, and Brovkn & Brenn stain. The results obtained were as follows: 1. The mean survival time of each group rat was 19.3$\pm$5.2 days (group 1), 41.1$\pm$14.0 days (group 2), 50.5$\pm$18.4 days (group 3), 43.0$\pm$22.9 days (group 4) or 21.8$\pm$5.1 days (group 5). Significant differences were noted between group 1 and group 2(p<0.01), group 1 and group 3 (p<0.01), and group 1 and group 4 (p<0.01), which represented bacterial infections were most fatal in immunocompromised rats. Group 5 revealed no difference in the survival day from group 1, while significant differences were noted between group 2 and group 5(P<0.01), group 3 and group 5(p<0.01), and group 4 and group 5(p<0, 01), which represented little importance of fungal infection as the cause of death of the rats. 2. The first fatality due to p. carinii pneumonia occurred 17 days after the beginning of the immunosuppression. The occurrence rate of P. carinii pneumonia in the decreasing order was 92.9% (group 3), 80.0% (group 2 and group 5), 78.6% (group 4) and 33.3% (group 1). With regard to the pathological stage of P. carinii pneumonia, the stage 1 was 11.3%, the stage 2, 28.3%, and the stage 3, 60.4%. 3. Viewing from the duration of immunosuppression, bacterial pneumonia chieay appeared in 1 month, mixed infections (P. carinii and bacteria, or p. carinii and fungi) in 1~2 months, and pure P. carinii pneumonia after 2 months. The present study revealed that P. carinii pneumonia was the most important cause of death of immunocompromised rats later than 1 month after the start of immunosuppression.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1559-1567
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• 2015

The combination of trimethoprim (TMP) and sulfamethoxazole (SMX) has been shown to be active against Mycobacterium tuberculosis (Mtb) in clinical tuberculosis (TB) treatment. However, the mechanism of action of TMP-SMX against Mtb is still unknown. To unravel this, we have studied the effect of TMP and SMX by deleting the folP2 gene in Mycobacterium smegmatis (Msm), and overexpressing the Mtb and Msm folP1/2 genes in Msm. Knocking out of the folP2 gene in Msm reduced the minimum inhibitory concentration of SMX 8-fold compared with wild type. Overexpression of the folP1 genes from Mtb and Msm increased the MICs by 4- and 2-fold in Msm for SMX and TMP, respectively. We show a strong correlation between the expression of folP1 and folP2 genes and TMP-SMX resistance in mycobacteria. This suggests that a combination of FolP2 inhibitor and SMX could be used for TB treatment with a better outcome.

• Analytical Science and Technology
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• v.29 no.3
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• pp.126-135
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• 2016

In the present study, we evaluated the efficiency of the drinking water treatment unit processes controlled by targeting high pharmaceutical compounds that are likely to be released into the water supply. In the coagulation process, the removal rate of sulfonamide, an antibiotic, amounted to 22.6~42.1 %, that of naproxen to 28.2 %, and that of acetaminophen to 20 %. Trimethoprim has demonstrated a low removal rate (4.4 %), while the removal rate of erythromycin was 2.4 %; aspirin was not removed at all. When applying a mixture of chlorination and the coagulation process, the removal rate was increased with increasing the chlorine dosage. When the chlorine injection with the concentration of 3 mg/L was applied, sulfonamide antibiotics, acetaminophen and naproxen, were completely removed. Trimethoprim exhibited a high removal efficiency of ca. 98%, while the removal efficiency of erythromycin was about 55 %; at the same time, aspirin showed a lower removal ratio (ca. 10 %). When applying the powdered activated carbon adsorption process, the removal rate was increased with increase of the concentration of the powder activated carbon injection. Sulfonamide antibiotics showed about 18~50 % removal efficiency in the 1 mg/L, the removal rate was increased by at least 80 % in 25 mg/L. The evaluation results of the titration injection concentration of chlorine treatment and adsorption, coagulation process for the efficient processing of the remaining pharmaceutical compounds in the water treatment process, when applying the chlorine 3 mg/L, powdered activated carbon 10 mg/L and coagulant 15 mg/L were removed more than 90 %.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.227-239
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• 2009

At the present study, it was aimed to detect virulence genes and antimicrobial resistance genes among 102 strains of 12 Salmonella serotypes isolated from pigs and cattle. In polymerase chain reaction (PCR), invA was detected from all strains of Salmonella spp., spvC was detected from Salmonella enterica serotype Enteritidis (S. Enteritidis) (100%), S. Bradenburg (75%), and S. Typhimurium (20.4%). Drug resistance related genes of 12 types were detected from all strains. TEM ($bla_{TEM}$) gene was detected from 51 (92.7%) of 55 $\beta$-lactams (54 ampicillin or 1 amoxicillin) resistance strains. 55 (100%) of 55 chloramphenicol resistance strains, 3 (100%) of 3 gentamicin resistance strains and 5 (100%) of 5 kanamycin resistance strains did contain cml, aadB, and aphA1-Iab, respectively. strB (89.9%), strA (88.4%), aadA2 (84.1%) and aadA1 (72.5%) were detected from 69 streptomycin resistance strains. sulII and dhfrXII were detected from 49 (100%) of 49 sulfamethoxazole/trimethoprim resistance strains, but sulI was not detected. tetA (97.9%) and tetB (21.6%) were detected from 97 tetracycline resistance strains. int gene was detected from 58 (56.9%) of 102 strains. 54 S. Typhimurium of 102 Salmonella spp. were attempted to detect drug resistance genes. TEM was detected from 44 (95.7%) of 46 $\beta$-lactams (45 ampicillin or 1 amoxicillin) resistance strains. cmlA was detected from 51 (100%) of 51 chloramphenicol resistance strains. aadA2 (100%), strA (100%), strB (100%), and aadA1 (79.6%) were detected from 54 streptomycin resistance strains. sulII (100%) and dhfrXII (100%) were detected from 49 sulfamethoxazole/trimethoprim resistance strains. tetA was detected from 54 (100%) of 54 tetracycline resistance strains. int gene was detected from 54 (100%) of 54 strains. The major drug resistance pattern and resistance gene profile were ampicillin, chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim and tetracycline (ACSSuT) and TEM, cmlA, aadA1, aadA2, strA, strB, sulII, dhfrXII, tetA and int, respectively.

• Parasites, Hosts and Diseases
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• v.53 no.3
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• pp.321-327
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• 2015

A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.

• YAKHAK HOEJI
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• v.34 no.2
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• pp.122-125
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• 1990

Antibiotic resistance patterns were determined for 14 strains of Staphylococcus aureus isolated at a hospital in Pusan during summer in 1989. Resistance to chloramphenicol or clindamycin was recorded in 100% of strains. Resistance to the other compounds tested was as follows: tetracycline 86%, gentamicin 79%, tobramycin 71%, kanamycin 71%, erythromycin 57%, ampicillin 57%, methicillin 50%, streptomycin 29%, cephalothin 29%, and trimethoprim 21%. All strains were sensitive to vancomycin and rifampicin. All strains showed multiple resistance to more than 3 antibiotics.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.146-149
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• 2013

Bacteria of genus Vibrio are Gram-negative, curved, halophilic, nonspore-forming bacteria, autochthonous inhabitans of the marine and estuarine environments. Some of the Vibrio species such as V. parahaemolyticus, V. vulnificus, and V. cholerae are associated with human disease. Each year many people have been suffering from food-borne disease caused by the ingestion of seafood. In this study, we have monitored antibiotic resistance of this microorganism in 6 coastal areas of West Sea by sampling shellfish monthly. Vibrio spp. were detected from 23.3% of 120 samples analyzed using TCBS agar plates as well as API 20E kit. Among 16 antibiotics tested, resistance to vancomycin and ampicillin was observed in 82.1% of the isolates, and Vibrio spp. resistant to rifampin (71.4%) and cephalothin (53.6%) were also high. Most of the isolates were sensitive to chloramphenicol (92.9%), sulfamethoxazole/trimethoprim (92.9%), and tetracycline (96.4%). About 71.4% of the isolates showed multiple drug resistance toward 3 antibiotics including vancomycin and ampicillin.