• Journal of Microbiology and Biotechnology
• /
• v.23 no.3
• /
• pp.329-334
• /
• 2013

Uridinediphospho-N-acetylglucosamine enolpyruvyl transferase (MurA, E.C. 2.5.1.7) is an essential bacterial enzyme that catalyzes the first step of the cell wall biosynthetic pathway, which involves the transfer of an enolpyruvyl group from phosphoenolpyruvate to uridinediphospho-Nacetylglucosamine. In this study, novel inhibitors of Haemophilus influenzae MurA (Hi MurA) were identified using high-throughput screening of a chemical library from the Korea Chemical Bank. The identified compounds contain a quinoline moiety and have much lower effective inhibitory concentrations ($IC_{50}$) than fosfomycin, a wellknown inhibitor of MurA. These inhibitors appear to covalently modify the sulfhydryl group of the active site cysteine (C117), since the C117D mutant Hi MurA was not inhibited by these compounds and excess dithiothreitol abolished their inhibitory activities. The increased mass value of Hi MurA after treatment with the identified inhibitor further confirmed that the active-site cysteine residue of Hi MurA is covalently modified by the inhibitor.

• Korean Journal of Microbiology
• /
• v.39 no.1
• /
• pp.36-39
• /
• 2003

The rapid and reliable 16S rDNA multiplex polymerase chain reaction (PCR) assay was established to characterize bacterial etiologies of middle ear effusion. These etiologies included Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumonia, which were detected in middle-ear effusion (MEE) samples taken from patient with otitis media. A total of 39 MEE samples were aspirated from 26 patients. DNA was extracted from MEE samples, and PCR was done with DNA extracts by using the common primers, which is localized at C4 region in the 16S rDNA gene of all bacterial species, and species-specific primers: (i) Haemophilus-specific primer, (ii) Moraxella- specific primer, and (iii) Streptococcus-specific primer. Among 39 samples tested, 24 (61.5%) were positive for H. influenzae, 10 (25.6%) were positive for M. catarrhalis, 3(7.7%) were positive for S. pneumonia, and 11 (28%) were negative for 165 rDNA multiplex PCR reaction. Nine samples (28.6%) exhibited a mixed infection and were positive for both H. infuenzae and M. catarrhalis. We suggested that 16S rDNA multiplex PCR is a useful method to identify rapidly for rapid identification of the pathogenic bacteria and characterization of bacterial etiologies of middle ear effusion.

• Pediatric Infection and Vaccine
• /
• v.27 no.3
• /
• pp.147-157
• /
• 2020

Purpose: We investigated the trend of antibiotic susceptibility of Haemophilus influenzae over 5 consecutive years. Methods: We analyzed the antibiotic susceptibility of H. influenzae isolated from children aged <18 years, who were admitted to the Asan Medical Center Children's Hospital from March 2014 to April 2019. Antibiotic susceptibility of H. influenzae was determined by the disk diffusion test according to the European Committee on Antimicrobial Susceptibility Testing guidelines. Results: Excluding duplicates, 69 isolates were obtained over the past 5 years. The median age of the patients was 5 years (range, 2.8-8.6 years). The antibiotic susceptibility patterns were as follows: ampicillin (AMP)-susceptible/amoxicillin-clavulanate (AMC)-susceptible (AS/ACS; n=15 [21.7%]), AMP-resistant/AMC-susceptible (AR/ACS; n=21 [30.4%]), and AMP-resistant/AMC-resistant (AR/ACR; n=33 [47.8%]). The prevalence of isolates with AR/ACR phenotype tended to increase from 42.1% in 2014-2015 to 54.5% in 2018-2019 (P=0.342). Compared to 2014-2015, the resistance rates to cefuroxime and ceftriaxone in 2018-2019 increased from 31.6% to 77.3% and from 0.0% to 59.1%, respectively (P=0.003 and P<0.001, respectively). Conclusions: Over the last 5 years, H. influenzae isolates with AR/ACR phenotype and ceftriaxone resistance were frequently observed at our institute. The incidence of resistance to cefuroxime and ceftriaxone has increased significantly.

• Asian-Australasian Journal of Animal Sciences
• /
• v.4 no.1
• /
• pp.21-24
• /
• 1991

A mixed infection of Haemophilus paragallinarum (Hpg), Mycoplasma gallisepticum (MG) and M. synoviae (Ms) was detected in layers of a poultry farm in Iwate prefecture in Japan by pathological, serological and bacteriological investigation. Hpg strains were isolated from three of five birds investigated and all strains were identified to be type C. The Hpg isolates were more susceptible in vitro to a combination of sulfamonomethoxine and ormetoprim (Ektecin) than each of sulfamethoxasol, sulfamonomethoxine, oxytetracycline, tetracycline, streptomycin, erythromycin and thianphinicol. After a total of six days' medication of 1% feed additive Ektecin, symptoms of infectious coryza of hens in the farm almost disappeared and no Hpg was detected even from birds showing nasal discharge.

• Journal of Veterinary Clinics
• /
• v.1 no.1
• /
• pp.53-61
• /
• 1984

Among the 308 breeding pigs imported via airway from Canada, 15 pigs died from the respiratory disease. Three of the carcases were examined by pathological and bacteriological means. In the lungs of the necropsied cases there was a lobar pleuropneumonia characterized by parenchymal hepatization, carnification and extensive adhesion between the thoracic organs due to fibrinous pleural thickening. Histologically the affected lungs had lesions of thrombosis and coalesced area of necrosis delineated by packed macrophages. A strain of Haemophilus Pleuropneumoniae was isolated from the affected lungs. The isolate was serologically identified as serotype 5.

• YAKHAK HOEJI
• /
• v.36 no.5
• /
• pp.455-459
• /
• 1992

Haemophilus K-12 producing novel sulfotransferase was isolated from mouce intestinal flora. The enzyme catalyzed the transfer of sulfate group from p-nitrophenylsulfate to phenolic compounds. The optimum medium condition for the sulfotransferase production was 0.2% sucrose, 1% yeast extract, $Na_{2}HPO_4$ and 0.5% NaCl. The enzyme production was induced by donor substrate, but was not by accepters. When p-nitrophenylsulfate was used as a donor substrate, 1-naphthol was best substrate, followed by phenol, p-acetaminophenol and tyramine.

• Journal of Chest Surgery
• /
• v.56 no.2
• /
• pp.136-139
• /
• 2023

Although cardiac myxoma is one of the most common types of benign cardiac tumors, infected cardiac myxoma is very infrequent. The diagnosis of infected cardiac myxoma may be challenging because the presenting symptoms are non-specific and established management guidelines are lacking. This report describes a 39-year-old woman with a 5-month history of uncontrolled fever, chills, and myalgia who was diagnosed with myxoma and underwent mass excision. Although blood and urine cultures were negative for growing bacteria, a pathologic examination showed that the excised mass was a left atrial myxoma, with pan-bacterial polymerase chain reaction (PCR) of the surgical specimen revealing Haemophilus parainfluenzae at 99.87%, resulting in a diagnosis of infected cardiac myxoma. Laboratory tests, such as PCR, may supplement culture results in the diagnosis of infected cardiac myxoma.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.9 no.6
• /
• pp.490-494
• /
• 2004

An efficacy test of PRP (polyribosylribitol phosphate)-TT (Tetanus toxoid) conjugate vaccines was carried out using BALB/c mice as an animal model by inoculating Haemophilus in­fluenzae type b (Hib) with a virulence enhancement factor (VEF). Three administrations of the conjugate vaccines at 2-week intervals elicited a significantly high level of PRP antibodies (P>0.0001). The protective activity of the PRP immunization was challenged with either Hib with iron dextran (Hib/) or with a combination of mucin and hemoglobin (Hibmh) as a VEF. The me­dium lethal dose $(LD_{50})$ for Hibmh and Hibiwas measured as 10 CFU (Colony Forming Unit) and $2.5{\times}10^{8}$ CFU respectively. Each immunized animal was challenged with five or ten times the $LD_{50}$ level of bacteria with a VEF. A significant difference in mortality between the immunized and control mice (P> 0.01) was observed with the Hibmh challenge inoculation but not with the Hibi challenge inoculation. These results show that a combination of mucin and hemoglobin was able to enhance the virulence of Hib in BALB/c mice to cause a lethal infection, thus suggesting that BALB/c mice introduced to this method can be an effective model animal for testing the protective efficacy of H. influenzae conjugate vaccines.

• Molecules and Cells
• /
• v.26 no.2
• /
• pp.206-211
• /
• 2008

HI0381 of Haemophilus influenzae was investigated by circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. HI0381 is a 153-residue peptidoglycan-associated outer membrane lipoprotein, and a part of the larger Tol/Pal network. Here, we report its backbone $^1H$, $^{15}N$, and $^{13}C$ resonance assignments, and secondary structure predictions. About 97% of all of the $^1HN$, $^{15}N$, $^{13}CO$, $^{13}C{\alpha}$, and $^{13}C{\beta}$ resonances covering 131 non-proline residues of the 134 residue, mature protein, were clarified by sequential and specific assignments. CSI and TALOS analyses revealed that HI0381 contains five ${\alpha}$-helices and five ${\beta}$-strands. To characterize the structure of HI0381, the effects of pH and salt concentration were investigated by CD. In addition, the structural changes occurring when HI0381 was in a membranous environment were investigated by comparing its HSQC spectra and CD data in buffer and in DPC micelles; the results showed that helix ${\alpha}4$ and strand ${\beta}4$ became aligned with the membrane. We conclude that the conformation of HI0381 is affected by the membrane environment, implying that its folded state is directly related to its function.

• Pediatric Infection and Vaccine
• /
• v.8 no.2
• /
• pp.234-240
• /
• 2001

Buccal cellulitis which presents with high fever and a swelling of the cheek with violaceous hue in young children is most often caused by H. influenzae. Bacteremia is common in buccal cellulitis caused by H. influenzae, and a culture of cerebrospinal fluid should be obtained because meningitis may be present despite the lack of meningeal irritation signs. Although buccal cellulitis is considered to be one of the important manifestations of H. influenzae infection, only two cases have been reported in Korea yet. We experienced a case of buccal cellulitis with H. influenzae bacteremia in an immunocompetent girl of 18-month-old. She was presented with high fever followed by rapidly progressive swelling and tenderness of both cheeks with violaceous hue in four hours. The blood culture revealed H. influenzae type b. There was no concurrent otitis media, sinusitis, or meningitis and no portal of entry was identified. Fever subsided two days after starting intravenous cefotaxime. Intravenous cefotaxime was subsequently changed to oral cefixime, and antibiotics were administered for a total of two weeks. We report this case with a review of related literature.