• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1609-1616
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• 2024

The Burkholderia cepacia complex (Bcc) consists of opportunistic pathogens known to cause pneumonia in immunocompromised individuals, especially those with cystic fibrosis. Treating Bcc pneumonia is challenging due to the pathogens' high multidrug resistance. Therefore, inhalation therapy with tobramycin powder, which can achieve high antibiotic concentrations in the lungs, is a promising treatment option. In this study, we investigated potential mechanisms that could compromise the effectiveness of tobramycin therapy. By selecting for B. cenocepacia survivors against tobramycin, we identified three spontaneous mutations that disrupt a gene encoding a key enzyme in the biosynthesis of cobalamin (Vitamin B₁₂). This disruption may affect the production of succinyl-CoA by methylmalonyl-CoA mutase, which requires adenosylcobalamin as a cofactor. The depletion of cellular succinyl-CoA may impact the tricarboxylic acid (TCA) cycle, which becomes metabolically overloaded upon exposure to tobramycin. Consequently, the mutants exhibited significantly reduced reactive oxygen species (ROS) production. Both the wild-type and mutants showed tolerance to tobramycin and various other bactericidal antibiotics under microaerobic conditions. This suggests that compromised ROS-mediated killing, due to the impacted TCA cycle, underlies the mutants' tolerance to bactericidal antibiotics. The importance of ROS-mediated killing and the potential emergence of mutants that evade it through the depletion of cobalamin (Vitamin B₁₂) provide valuable insights for developing strategies to enhance antibiotic treatments of Bcc pneumonia.

• Journal of Chest Surgery
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• v.25 no.10
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• pp.1055-1060
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• 1992

Clinical experience of 21 patients with infective endocarditis was reviewed. Endocarditis involved the left-sided valve in 16 cases, the right-sided valve in 2, and PDA in the remaining 3 patients. Valve abnormalities included leaflet perforation in 9 patients, chordal rupture in 2,; annular abscess in 6; and aorticoleft atnal perforation in 2. Sixteen patients underwent valve replacement[aortic valve replacement in 7 patients, mitral replacement in 4 and double valve replacement in 5], two had VSD closure with pulmonary valve excision, three had ductus arteriousus closure. The patients were classified into two groups. I ] Healed endocarditis group: including the patients who had completed a planned cou-rseof antibiotic therapy[N=10], II ] Active endocarditis group: patients in which operations were performed prior to completetion of antibiotic treatment course[N=11]. The indications for operation included congestive heart failure, embolism, and persistent sepsis. Organisms were predominantly streptococcus[N=5] and staphylococcus [N=4] followed by candida, moraxella, and E-coli. By NYHA functional classification, all patients were in Class III or IV preoperatively. There was only one operative mortality in patient from group II. All patients substantially, improved postoperatively with NYHA classification in class I or II. This study shows that early surgical intervention in patients with active endocarditis has desirable outcome.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.1
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• pp.46-54
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• 1995

Postoperative infection following orthognatic surgery is rare. When postoperative infections occur, the initial treatment consists of incision and drainage of the affected area, culturing to identify bacterial stains and verify antibiotic sensitivity, and the institution of the appropriate antibiotic regimen. Some plates and screws may eventually require removal, the initial therapy should be attempted to retain the plates and screws until adequete healing has taken place. In orthoganthic surgery, intra-operative complications as a lesion of inferior alveolar nerve, fracture of osteomised segments, incomplete sectioning, malposition of segments, haemorrhage may occur. The surgeon should be familiar with possible complications to be caused and how to manage them. Prevention of postoperative infection following the orthognathic surgery consists of minimal periosteal reflection, aseptic management of operation field, proper surgical technique, rigid fixation, prophylactic antibiotics.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.19-29
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• 1991

The purpose of this study was to evaluate the usefulness of Ga-67 scintigram in predicting the disappearance of inflammatory activity in mandibular lesions of dogs. Inflammatory bony lesions were produced artificially by the injection of sclerosing solution and bacterial suspension through the distal root canals of the lower 4th premolars in 10 dogs. The serial Ga-67 scintigrams and periapical radiograms were obtained. After 3 to 6 weeks duration of antibiotic therapy, the experimental animals were killed, and the mandibles were dissected. Bacteriologic culture and antibiotic sensitivity test were done. 1. The following results were obtained. The negative Ga-67 scan has 100% predictive value, and is a strong evidence of the resolution of inflammatory activity. In 2 animals of positive Ga-67 scan, I animal had negative culture. In 14 cases of positive Ga-67 scan, radiographically there was increase in the size of lesion in 9 cases, no change in 5 cases. In 8 cases of negative Ga-67 scan, radiographically there was increase in the size of lesion in I case, no change in 6 cases and decrease in 1 case.

• Pediatric Infection and Vaccine
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• v.5 no.2
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• pp.276-282
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• 1998

Staphylococcal pneumonia caused by staphylococcus aureus can be characterized by its severity and rapid progress as a bacterial infection. The disease shows a high mortality in younger patients, especially in infants unless early and appropriate treatment is carried out. Treatment can be made of medical method alone but in cases of surgical interventions are needed, immediate surgical methods such as closed or open drainage of pleural fluid, lobectomy and decortication should be followed with combination of medical therapy. The choice of antibiotic should be made by proper antibiotic sensitivities tests. For a methicillin sensitive S. areus(MSSA), the penicillase resistant penicillin would be the first choice and for a methicillin resistant S. aureus (MRSA), the glycopeptides such as vancomycin would be the first one. Other drugs can also be used if the bacterial agents show any sensitivities to these drugs. Commonly, the chest roentgenographic findings reveal infiltrations, empyema, pneumothorax, pleural effusion, atelectasis or pneumatoceles in staphylococcal pneumonia and this fact easily can lead the physicians to its diagnosis as soon as possible. We experienced 5 cases of staphylococcal pneumonia in infants, proven by through bacterial cultures and report them with brief review of the related literatures.

• The Journal of Internal Korean Medicine
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• v.36 no.2
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• pp.207-216
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• 2015

Objectives: The purpose of this study is to report the clinical application of acupuncture, herbal medication, and antibiotic treatment to a patient with a diabetic foot infection. Methods: We treated the patient-who had ulcerations of the 1st, 2nd, and 4th toes and osteomyelitis on the right 1st and 2nd toes-with acupuncture, herbal medication, and antibiotics. We measured the state of this case by changes in his MRI signal and ulceration of his toes. Results: After treatment, the MRI signal indicated that the osteomyelitis had disappeared and the ulceration was diminished. Conclusions: A combination of acupuncture, herbal medication, and antibiotic treatment is effective for treatment of ulceration and osteomyelitis caused by diabetic foot infection.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.838-844
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• 2016

In this study, epidemiological cut-off values were estimated for 44 Photobacterium damselae isolates, since clinical breakpoints have not been established for this pathogenic bacterium. The susceptibility of the isolates to 10 antibiotics was evaluated using internationally standardized disc diffusion protocols. Normalized resistance interpretation was used to generate statistically valid epidemiological cut-off values for the susceptibility data. There were not enough strains exhibiting full sensitivity to ampicillin and amoxicillin to allow analysis of these antibiotics. Because there were only a marginally sufficient number of strains exhibiting full sensitivity to oxytetracycline, the cut-off value generated provided only a provisional estimate. The valid wild-type cut-off values were <13, 13, 9, 22, 25, 27, and 28 mm for gentamicin, cephalexin, erythromycin, oxolinic acid, flumequine, florfenicol, and sulfamethoxazole/trimethoprim, respectively. The application of these cut-off values should greatly facilitate the rational selection of antibiotics for use in commercial fish farms.

• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.31.1-31.7
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• 2018

Despite considerable focus on the regenerative endodontic treatment of immature teeth with necrotic infected pulps and apical periodontitis, little data exist with regard to its possible implementation in necrotic permanent teeth with complete apical and radicular development. The present report describes the procedures and outcome of a regenerative endodontic treatment approach in 2 previously-traumatized incisors with closed apex with apical periodontitis. A 2-visit treatment procedure was employed. At initial visit, the root canals were copiously irrigated, followed by placement of a triple antibiotic paste containing ciprofloxacin, metronidazole, and clindamycin into the root canals. After 4 weeks, the antibiotic paste was removed, and apical bleeding was initiated with size 10 hand files beyond the apices. The root canals were coronally sealed with mineral trioxide aggregate, and the access cavities were restored with bonded resin composite. At post-operative 60 months, both teeth were remained asymptomatic, with the recall radiographs showing complete resolution of apical radiolucency and reestablishment of periradicular tissues. In both teeth, the dimensions of root space remained unchanged as verified by image analysis. The revitalization protocol utilizing root canal disinfection and induced apical bleeding in necrotic, closed-apex incisors may offer a clinically acceptable alternative to conventional root canal treatment.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.214-221
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• 2018

Clostridium difficile infection (CDI) is a rapidly emerging infection that may have devastating consequences. Prompt and accurate diagnosis is crucial for management and control. The aim of this study was to determine the incidence of C. difficile associated diarrhea among hospitalized patients, and to compare different diagnostic laboratory methods for detection of toxin producing strains in clinical specimens. The study was conducted at a university hospital in Cairo during the period from May 2013 till June 2015. Subjects were under antibiotic therapy and presented with hospital-acquired diarrhea. Four hundred and sixty-five stool specimens were processed by different microbiological methods. C. difficile was recovered in culture in 51 of stool specimens. Of these, 86.3% to 98% were positive for toxin production by 2 different methods. This study showed that antibiotic intake is the major risk factor for development of hospital-acquired diarrhea. We evaluated different microbiological methods for diagnosis of C. difficile. We recommend the use of toxigenic culture as a gold standard for microbiological diagnosis of C. difficile.

• Clinical and Experimental Pediatrics
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• v.64 no.8
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• pp.415-421
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• 2021

Background: Antibiotic resistance is associated with longer hospitalizations, higher treatment costs, and increased morbidity and mortality rates. Purpose: This study aimed to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Iranian children. Methods: International databases, including Web of Science, PubMed, Embase, and Scopus, and Iranian databases, including Scientific Information Database (www.sid.ir), Magiran, and Iranian Database for Medical Literature (idml.research.ac.ir), were systematically searched for articles published between January 2000 and August 2019. Sources of heterogeneity were determined using subgroup analysis and meta-regression. Results: Overall, 343 studies were identified; of them, 20 were included in the meta-analysis to estimate the pooled prevalence. The pooled prevalence of MRSA was 42% (95% confidence interval [CI], 29-55) among culture-positive cases of S. aureus, 51% (95% CI, 39-62) in hospitalized children, and 14% (95% CI, 0.05-27) in healthy children. Conclusion: The overall pooled prevalence of MRSA in children was 42%. Appropriate infection control measures and effective antibiotic therapy are needed.