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Biomedical subjects

N Rikitomi

Publications and source records attributed to N Rikitomi.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Clinical study of 18 patients whom MRSA was detected from stool--especially about comparison enterocolitis with colonization].

We studied the clinical aspects of 18 patients from whom MRSA was detected from the stool and compared with 9 enterocolitis cases (7 male, 2 female, median age 72.4 y.o.) with 9 colonization cases (5 male, 4 female, median age 70.2 y.o.) from 1991 June to 1995 May. Cases of postoperative, use of anti-peptic ulcer drugs and administration of antibiotics for enterocolitis were more than that of colonization. On the other hand, eatable patients in the colonization group who could take food orally were more in number. Many patients of both enterocolitis and colonization were colonized in the respiratory tract. Drug sensitivity of MRSA in both cases were almost the same and the coagulase type were all that of II. Three courses on how MRSA enterocolitis occurs is considered. At first, colonization in the respiratory tract, second, proliferation of MRSA in the higher pH gastric juices as a result of gastrectomy or use of anti-peptic ulcer drugs, and third, selection of MRSA after administration of antibiotics.

Aged↗
PubMed1994

The role of MRSA (methicillin-resistant Staphylococcus aureus) adherence and colonization in the upper respiratory tract of geriatric patients in nosocomial pulmonary infections.

The mechanism of nosocomial respiratory infections caused by MRSA (methicillin-resistant Staphylococcus aureus) in geriatric patients was investigated. Seriously ill patients (SIP) undergoing naso-gastric tube feeding or intravenous hyperalimentation and moderately ill patients (MIP) who were orally fed, were examined for their colonization and infection by Staphylococcus aureus (S. aureus) in the respiratory tract. Colonization of MRSA in the upper respiratory tract in SIP was from six to ten times higher than that in MIP and was associated with a high incidence of MRSA pulmonary infections. In vitro S. aureus adherence to nasal or oropharyngeal cells demonstrated that bacteria binding to nasal cells was higher, which probably can be interpreted as an elevated occurrence of S. aureus colonization in the nasal cavity than in the throat. The binding activity of MRSA was not superior to that of MSSA (methicillin-sensitive S. aureus). Though MRSA binding to the nasal cells from SIP was not higher than those from MIP, MRSA colonization in the upper respiratory tract was more frequently seen in SIP (P < 0.01). A higher incidence of total infectious episodes (P < 0.02-0.001) and more frequent use of antibiotics (P < 0.02-0.001), which were potent against MSSA might be the basis for selection of MRSA in these patients. In fact, the rate of MRSA colonization on the skin (pressure sores) was also higher in SIP (P < 0.01). A low nutritional state in SIP (P < 0.01-0.02) might also be associated with MRSA colonization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Gram-negative coccus infection].

The main pathogens of gram-negative infections are Neisseria gonorrhoeae, Neisseria meningitidis and Moraxella catarrhalis infection. N. Gonorrhoeae infection is one of the STD, but the chemotherapy for this infection is very easy because this pathogen is very susceptible to new quinolones. Meningococcal infection is very rare in Japan. Since 1980, M. catarrhalis is one of the important pathogen of respiratory infections such as acute bronchitis, pneumonia, chronic bronchitis. This pathogen also causes acute sinusitis and otitis. Most pathogenic strains of M. catarrhalis are beta-lactamase producing.

Animals↗
PubMed1993

[A case of Kartagener's syndrome with S. pneumoniae lung abscess].

A 38-year-old male with Kartagener's syndrome (KS) was admitted to our department for evaluation of recurrent pneumonia. Before admission the patient was diagnosed as having pneumonia in another hospital and received ofloxacin (300 mg/day). Fever and production of purulent sputum decreased initially but again increased in the middle of April. On admission the films of both X-ray and CT scan of the chest revealed several air-fluid levels and infiltrative shadows on the left lower lung field. The patient was diagnosed as lung abscess using bronchofiberscopy. Gram staining of the intrabronchial specimens revealed many Gram-positive cocci and neutrophils including phagocytosed bacteria. A new carbapenem (L-627, 600 mg/day), was started intravenously. After the therapy Streptococcus pneumoniae were eradicated soon from the sputum. At the same time the above symptoms including dyspnea on exertion subsided, and the findings of the chest X-ray and CT scan were also improved. Regarding KS the electron micrograph of the cilia showed the absence of the outer-dynein arms. While by both the saccharin test and the sputum cytology impaired mucociliary clearance was found. Lung abscess infrequently accompany KS. There are reports of respiratory infections in KS, but to our knowledge no report of lung abscess was found in KS. We present this case report describing lung abscess in KS.

Adult↗
PubMed1992

Ultrastructural study on the adherence of Branhamella catarrhalis to oropharyngeal epithelial cell.

In the present study, it was observed that Branhamella catarrhalis adhere to the microplicae of the oropharyngeal epithelial cells. Both long and short microplicae patterns are present on the surface of oropharyngeal epithelial cells and the adherence ability of fimbriated Branhamella catarrhalis also varies according to the microplicae pattern. It was found that Branhamella catarrhalis attached more to one surface of the epithelial cell than to the other, suggesting that the presence of receptors are more on one surface than on the other. Branhamella catarrhalis did not attach to the mucus layer but directly to the epithelial cell surface. Ruthenium red staining specimen showed that Branhamella catarrhalis attached to a granular ruthenium red positive layer on the microplicae and also to a ruthenium red positive component, external to the unit membrane of the epithelial cell membrane.

Bacterial Adhesion↗
PubMed1992

Fimbriation, hemagglutination and adherence properties of fresh clinical isolates of Branhamella catarrhalis.

This study investigated the fimbriation on 24 fresh clinical isolates of Branhamella catarrhalis by electron microscopy. All the strains were isolated from patients with respiratory infections. The Branhamella catarrhalis strains were classified into three groups according to the grade of fimbriation. Among these 24 strains the incidence of densely fimbriated, moderately fimbriated and sparsely fimbriated isolates were 12 (50%), 7 (29%) and 5 (21%), respectively. After five-times serial subculture on Brain Heart Infusion agar, the average number of fimbriae per bacteria was decreased from 174 to 114 in the densely fimbriated strain and from 48 to 10 in the moderately fimbriated strain. Moreover, 20% of the population became non-fimbriated in moderately fimbriated strain after the serial subculture. In strains with higher hemagglutination titer the number of fimbriae was significantly (P < 0.04) more than in strains with lower hemagglutination titer.

Bacterial Adhesion↗
PubMed1991

Possible presence of a capsule in Branhamella catarrhalis.

Clinical isolates of Branhamella catarrhalis from patients with respiratory infections were used in this study. Electron microscopic observation after treating Branhamella catarrhalis with immune serum and ruthenium red revealed the capsule. In the phagocytosis test, most organisms were not ingested by human polymorphonuclear neutrophils in the presence of normal rabbit serum (NRS), while organisms were primarily cell associated and apparently ingested in the presence of immunized rabbit serum (IRS). The capsule may be one of the virulence factors in this bacteria. This study demonstrates the possible presence of a capsule in Branhamella catarrhalis.

Microscopy, Immunoelectron↗
PubMed1991

Mechanism of adherence of Moraxella (Branhamella) catarrhalis.

We examined the mechanisms of adherence of Moraxella catarrhalis to nasopharyngeal epithelial cells. Fimbriae were detected by electron microscopy on most of the strains studied. A role of fimbriae in adherence was supported by the reduction in adherence by treatments denaturing the fimbriae or by antifimbrial antibodies. There was, however, no significant difference in adhesive capacity or hemagglutination between fimbriated and non-fimbriated strains. Furthermore, there was no correlation between hemagglutination and adherence. The possibility that receptor epitopes were provided by cell surface glycolipids was examined by thin-layer chromatography. Glycolipids from various sources, including nasopharyngeal cells were separated by thin layer chromatography plates and overlayed with bacteria. No binding was detected. The results suggest that lectin-glycolipid interactions do not explain the attachment of M. catarrhalis to epithelial cells.

Adult↗
PubMed1990

Electron microscopic observation of Branhamella catarrhalis.

The hemagglutination (HA) test was done on 85 strains of Branhamella catarrhalis, isolated from sputum of patients with respiratory infections; 53% were HA positive strains. Three HA positive and three HA negative strains were selected and were observed under the electron microscope. The bacterial cell wall appeared to be lobulated and its total thickness was about 38 nm. The nuclear region consisted of whorls or fibrils and dense bodies. Five strains were fimbriated and one strain was nonfimbriated. The size of fimbriae was about 68 nm in length and 4.5 nm in width. The fimbriae of Branhamella catarrhalis were densely arranged and peritrichous in distribution. There was no change of fimbriation between broth and agar cultures.

Bacterial Infections↗
PubMed1990

Effect of ampicillin, cefmetazole and minocycline on the adherence of Branhamella catarrhalis to pharyngeal epithelial cells.

Using pharyngeal epithelial cells from a healthy adult and eight strains of Branhamella catarrhalis (B. catarrhalis) isolated from eight patients with respiratory infection the effect of subminimal inhibitory concentrations of cefmetazole, ampicillin and minocycline on adherence was examined. Cefmetazole-treated bacterial attachment (44 +/- 28; mean +/- S.D.) decreased significantly (p less than 0.05) compared to the control (84 +/- 27). Statistically no significant difference in adherence was found between ampicillin-treated bacteria (63 +/- 36) and the control (95 +/- 40) or minocycline-treated bacteria (91 +/- 39) and the control (109 +/- 40). Large bacteria was observed after cefmetazole and ampicillin treatment. In addition to diplococci, tetrads were observed after cefmetazole treatment. Significant correlation between the MICs and adherence ability was not found. The results suggests that these three antibiotics were not responsible for the increase in B. catarrhalis infection by increasing adherence ability.

Ampicillin↗
PubMed1990

[Respiratory infections caused by Branhamella catarrhalis in 5 different hospitals].

During 9 months (from January 1988 to September 1988), we experienced 82 patients (94 episodes) of respiratory infections with Branhamella catarrhalis in 5 different hospitals. There were 11 patients of acute bronchitis, 8 patients of pneumonia, 56 patients of chronic bronchitis (68 episodes), 3 patients of bronchiectasis, 3 patients of bronchial asthma with infection and chronic pulmonary emphysema in one patient. Ten cases of acute bronchitis and 3 cases of pneumonia had a recent history of common cold, with no underlying disease. There were 68 episodes of acute exacerbation of chronic bronchitis, the highest among 94 episodes of all respiratory infection. In chronic bronchitis the single pathogen B. catarrhalis was more than B. catarrhalis associated with other pathogens. H. influenza was associated with B. catarrhalis in in most cases of polymicrobial infection. beta-lactamase producing B. catarrhalis was 71% and oral penicillin was not effective in 8 cases of infection by beta-lactamase producing strains. These results show that B. catarrhalis is very important as a common pathogen of respiratory infection.

Adult↗
PubMed1990

[The antimicrobial activity of fluoroquinolone agents against pathogenic organisms in respiratory tract infections and its clinical effect].

The efficacy rate, minimal inhibitory concentrations (MICs), and resistance of fluoroquinolone agents against causative organisms in respiratory tract infections from January to March, 1988 were investigated. Of 333 pathogenic strains 85% consisted of 5 major causative organisms of respiratory tract infection (Haemophilus influenzae, Pseudomonas aeruginosa, Streptococcus pneumoniae, Branhamella catarrhalis, and Staphylococcus aureus). In 61 (59 cases) of these 333 strains, including 3 cases of acute pharyngitis, 5 of acute bronchitis, 3 of pneumonia, and 48 of chronic lower respiratory tract infection fluoroquinolone agents were administered. The efficacy rate was 76.3% in all cases, and 75% in cases with chronic lower respiratory tract infection. The fluoroquinolone agents were 100% effective in H. influenzae and B. catarrhalis, though the efficacy rate was 67% in S. aureus and 40% in P. aeruginosa. The susceptibility of all strains to fluoroquinolone agents were investigated. There was no resistant strain in H. influenzae and B. catarrhalis, though resistant strains to fluoroquinolone agents have increased in S. aureus and P. aeruginosa. The efficacy rate was investigated using the MIC of administered fluoroquinolone agent against causative organisms. It is surmised that the efficacy of that agent has an MIC of 1.56-3.13 micrograms/ml.

Anti-Bacterial Agents↗
PubMed1989

[Role of normal microflora in the throat in inhibition of adherence of pathogenic bacteria to host cells: in vitro competitive adherence between Corynebacterium pseudodiphtheriticum and Branhamella catarrhalis].

Our previous study showed the occurrence of Branhamella catarrhalis (B. catarrhalis) pulmonary infections which varies seasonally. To investigate the role of normal throat microflora in this seasonal variation of the occurrence of B. catarrhalis infection, seventy seven throat cultures were done in 45 patients with chronic pulmonary diseases from January to December in 1985. The isolation rate of Corynebacterium species as normal microflora was relatively higher in summer than in winter. Therefore in vitro competitive adherence to human epithelial cells between Corynebacterium pseudodiphtheriticum (C. pseudodiphtheriticum) and B. catarrhalis was done to examine bacterial interference. Preincubation or simultaneous incubation of C. pseudodiphtheriticum reduced the number of B. catarrhalis adherent to epithelial cells (p less than 0.02). The mean number of adherent C. pseudodiphtheriticum (average; 13.86) was higher than that (average; 1.22) of adherent B. catarrhalis. There was no antagonism in the growth on blood agar between C. pseudodiphtheriticum and B. catarrhalis. These findings suggest Corynebacterium species as normal throat microflora may interfere the adherence of B. catarrhalis to human epithelial cells and may protect against colonization and infection with B. catarrhalis. Bacterial interference of Corynebacterium species may be associated with the low occurrence of B. catarrhalis pulmonary infections in summer.

Adult↗