Efecto de la infección periodontal por porphyromonas gingivalis en el desarrollo de ateroesclerosis en ratones deficientes de apolipoproteína E / Effects of porphyromona gingivalis periodontal infection upon atherosclerosis development in apolipoprotein-E

Introducción: Nuestro grupo recientemente demostró una asociación significativa entre periodontitis, placas coronarias aguda y extensión de la enfermedad coronaria aterosclerótica en pacientes con síndrome coronario agudo. Objetivo: Desarrollar un modelo experimental animal para estudiar el posible efecto pro-aterogénico de la inducción de periodontitis por Porphyromona Gingivalis (PG) en ratones deficientes en la apolipoproteína E (APO-E KO). Métodos: En 12 ratones APO-E KO mantenidos con dieta hiperlipidémica se realizaron tocaciones con PG cepa ATCC 53977 en el surco gingival de los molares mandibulares a las 8 semanas de vida. Igual número de ratones APO-E KO fue intervenido con el mismo procedimiento, pero sólo con el vehículo de las tocaciones. Estos procedimientos se repitieron a las 48, 72 y 120 hrs de la infección inicial. Luego de 4 semanas post-inoculación con PG se realizaron estudios histomorfométricos en la aorta proximal para medir la severidad de las lesiones ateromatosas y en las mandíbulas, para evaluar la pérdida del hueso alveolar. Resultados: No se observó una diferencia significativa en el daño del hueso alveolar en las mandíbulas de los animales infectados versus el grupo control. En las aortas, la razón tamaño placa/pared vascular fue mayor en el grupo infectado con PG que en el grupo control (0.132 ± 0.2 versus 0.103 ± 0.15, respectivamente), pero esta diferencia no fue estadísticamente significativa. Conclusión: El diseño experimental del presente estudio no permitió establecer si la periodontitis inducida por PG es capaz o no de acelerar el proceso aterogénico de los ratones APO-E KO. Será necesario aplicar un protocolo de infección periodontal más agresivo en estos animales para evaluar más adecuadamente el efecto de PG sobre la ateroesclerosis.

[Detection of pyrogenic exotoxin SpeA, SpeB and SpeC genes in Chilean streptococci isolates and their association with clinical manifestations]. / Detección de los genes de las exotoxinas pirogénicas SpeA, SpeB y SpeC en cepas chilenas de Streptococcus pyogenes y su asociación con la clínica.

BACKGROUND: The virulence of Streptococcus pyogenes is determined by a variety of structural molecules, toxins and complex enzymes. Pyrogenic exotoxins cause fever, erythematous reactions, cytotoxic and immunological effects. AIM: To assess the frequency of speA, SpeB and SpeC genes in Chilean Streptococcus pyogenes strains and their association with the invasiveness of infections. MATERIAL AND METHODS: The genes for pyrogenic exotoxins SpeA, SpeB and SpeC were determined by polymerase chain reactions in 114 strains of group A Streptococcus pyogenes isolated from Chilean patients with invasive or non invasive infections. RESULTS: The gene for SpeA was present in 30.7% of isolates, the gene for SpeB was present in 69.3% and the gen for SpeC in 44.7% of isolates. The gene for SpeA was present in 20 of 33 invasive infections and in 15 of 81 non invasive infections (p < 0.0001). On the contrary, the gene for SpeC was present in 11 of 33 invasive infections and in 41 of 81 non invasive infections (p < 0.05). The frequency of speB was similar in invasive and non invasive infections. CONCLUSIONS: There is a clear relationship between the presence of SpeA genes and the severity of infections caused by Streptococcus pyogenes.

[Surveillance of gram positive cocci susceptibility to betalactams, glycopeptides, and other antimicrobials]. / Vigilancia de susceptibilidad de cocáceas grampositivas a betalactámicos, glicopéptidos y otros antimicrobianos.

BACKGROUND: During the last decade, there has been a progressive increase in the resistance of gram (+) cocci to betalactamics and other antimicrobials. Therefore, vancomycin and teicoplanin have incorporated as alternative antimicrobial drugs. AIM: To assess the susceptibility of gram (+) cocci to different antimicrobials including vancomycin and teicoplanin. MATERIAL AND METHODS: We studied 447 strains of gram (+) cocci coming from ambulatory and hospitalized patients. These included 308 Enterococcus sp strains, 99 Staphylococcus aureus strains and 40 coagulase negative Staphylococci strains. Enterococci susceptibility was measured using minimal inhibitory concentrations in agar and that of Staphylococci, through diffusion. Susceptibility to vancomycin and teicoplanin was measured using minimal inhibitory concentrations in all strains. RESULTS: Enterococcus faecalis was 100% susceptible to ampicillin, penicillin, vancomycin and teicoplanin, 23% susceptible to tetracyclin and 47% to chloramphenicol. Susceptibility of E faecium was 61% to penicillin, 49% to chloramphenicol, 41% to tetracyclin, 100% to vancomycin and teicoplanin. Of 19 Enterococcus spp strains, 90% were susceptible to ampicillin, 80% to penicillin, 55% to chloramphenicol and 45% to tetracyclin. Only one E casseiflavus strain had a low level resistance to vancomycin and was susceptible to teicoplanin. No Staphylococcus aureus strain was resistant to vancomycin or teicoplanin. CONCLUSIONS: A permanent surveillance of gram (+) cocci antimicrobial susceptibility is required to update therapeutic schemes.

Microbiology of recurrent parotitis.

BACKGROUND: Infantile chronic recurrent parotitis (ICRP) is characterized by episodes of recurrent swelling of the parotid gland with decreased salivary flow and purulent secretion. The etiology of this little unknown clinical condition has been attributed to multiple causes such as canalicular system malformations, ascending bacterial infection, hyposialia, parotitis sequelae, viral infections and immunologic disorders, among others. METHODS: We studied the types (with counts) of microorganisms involved in ICRP. Saliva samples were obtained from 56 patients and 20 controls, inoculated onto enriched media and incubated under aerobic and anaerobic conditions. Antimicrobial susceptibility and serotyping of the isolated organisms isolated were performed. RESULTS: Of 57 saliva samples from ICRP patients, 52 (91%) were culture-positive. The most frequently isolated microorganisms were Streptococcus pneumoniae and Haemophilus influenzae. Thirteen of twenty (65%) samples were also culture-positive, mostly for viridans streptococci. However, colony counts were lower than in clinical samples (P < 0.004). Approximately one-third of S. pneumoniae strains resistant or moderately resistant to penicillin, and all H. influenzae strains were susceptible to all of the antimicrobials tested. CONCLUSIONS: S. pneumoniae or H. influenzae were isolated in high concentrations in IRCP cases but not in controls, suggesting that these microorganisms may have a role in the development of this clinical entity. Quantitative cultures are very important in assessment of the pathogenic role of these microorganisms in patients but not in controls.

[Streptococcus pyogenes: in vitro susceptibility to several antimicrobials in two date periods]. / Streptococcus pyogenes: susceptibilidad in vitro a diversos antimicrobianos en dos períodos.

BACKGROUND: The frequency of Streptococcus pyogenes infections with deep tissue invasion and toxic shock syndrome has increased in the last decade throughout the world. AIM: To compare antimicrobial susceptibility of S. pyogenes strains isolated during 1986 and during 1994-95. MATERIAL AND METHOD: Eighty two S. pyogenes strains isolated in 1986 and 67 strains isolated in 1994-95, were studied. MIC 50 and 90 were determined by and agar dilution method for penicillin, ampicillin, cefazolin, cefuroxime, erythromycin, roxithromycin and miocamycin. RESULTS: Eighty eight strains came from skin of soft tissues, 19 from surgical wounds, 18 from invasive infections, 15 from pharyngeal swabs and 9 from other locations. All strains were susceptible to penicillin, ampicillin, cefazolin, cefuroxime, roxithromycin and miocamycin. Ninety nine percent of strains were susceptible to erythromycin. Strains isolated in 1995-95 had a higher MIC 50 and 90 for erythromycin than those isolated in 1986. CONCLUSIONS: The changes in susceptibility to erythromycin of recently isolated strains could be due to the widespread use of macrolides in Chile.

[Identification of Enterococcus species from clinical samples and their antimicrobial susceptibility]. / Identificación de especies de Enterococcus en muestras clínicas y susceptibilidad a agentes antimicrobianos.

The genus enterococcus has 12 species of which, E faecalis and E faecium are most important in human infections. A progressive resistance to penicillin and ampicillin has been detected in these species. The aim of this work was to identify Enterococcus species isolated in a hospital and to study their antimicrobial susceptibility. We studied 209 Enterococcus species coming from patients admitted to a public hospital. Their susceptibility to penicillin, ampicillin, imipenem, vancomycin, tetracycline, chloramphenicol, ciprofloxacin, gentamicin and streptomycin was determined with the agar dilution technique. Eighty seven percent of species were E faecalis and 7.1% were E fecium, other isolated species were E hirae, E casseliflaws, E avium, E solitarius and E faecalis variant. Thirty eight percent of these species were isolated from the urinary tract, 22% from the skin and 14% from surgical wounds. All E faecalis species were susceptible to penicillin, ampicillin, imipenem and vancomycin; 27.3% were susceptible to tetracycline, 54.7% to chloramphenicol and 80% to ciprofloxacin. Seventy three percent of E faecium species were susceptible to penicillin, 80% to ampicillin and 60% to imipenem. Sixty two percent of E faecalis and 42.4% of E faecium were resistant to streptomycin. It is concluded that the correct identification of Enterococcus species has therapeutic implications.

Occurrence of certain bacterial species and morphotypes in juvenile periodontitis in Chile.

The occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, Fusobacterium nucleatum, Campylobacter rectus, Capnocytophaga species, and certain bacterial morphotypes was determined in 18 affected and 18 unaffected sites in 10 localized juvenile periodontitis (LJP) patients, and in 10 affected and 10 unaffected sites in 5 generalized juvenile periodontitis (GJP) patients. The subgingival proportion of the 7 bacterial species was determined by selective and nonselective culturing. The results showed that when considering the pure prevalence of bacteria ( > 0%) there were significant differences (P < 0.05) in the subgingival plaque microflora of the affected sites versus those of the unaffected sites for P. gingivalis, A. actinomycetemcomitans, P. intermedia, E. corrodens, C. rectus, and F. nucleatum in LJP, and for P. gingivalis, P. intermedia, and F. nucleatum in GJP. The mean proportions of cocci, motile rods and spirochetes were also significantly different (P < 0.05) in affected sites compared to unaffected sites. Capnocytophaga sp, F. nucleatum, P. intermedia, and E. corrodens were found in more than 75% of affected sites in LJP. When taking the approach that an organism, to be associated with periodontal disease, has to be detected above a certain minimum threshold, the results indicated that bacteria most frequently associated with LJP and GJP in Chile are P. gingivalis (66% of LJP and 80% of GJP affected sites), and A. actinomycetemcomitans (44% of LJP and 50% in GJP affected sites). Different bacterial species may be judged to be important in the disease process depending upon whether a pure bacterial prevalence, or a prevalence above a certain detection level, is considered.

[Clinical and microbiological study of acute pelvic inflammatory disease]. / Estudio clínico y microbiológico de la enfermedad inflamatoria pélvica aguda.

Upper genital tract infection was investigated in 46 women admitted to hospital with clinic diagnosis of acute pelvic inflammatory disease (PID) and 62 control women accepted to hospital for laparoscopy Fallopian tubes sterilization. Diagnosis was ratified by laparoscopy in mild and moderate salpingitis; culdocentesis and ultrasonography were performed in severe salpingitis and endometrial sample was made in endometritis. Microbiological specimens were taken from the cervix and abdomen. Antecedents and complete clinical studies were obtained. Patients were treated with antibiotic association sodic G penicillin, chloramphenicol and gentamicin. Risk factors to development PID were: single female (p < 0.05), multiple sexual partner (p < 0.01), previous PID (p < 0.05), infertility (p < 0.05), mean year of IUD use in severe salpingitis (p = 0.05) and mean years of age from women with sexually transmitted bacterias (STB) vs endogenous bacterias (EB) (p < 0.05). In the control group no abdomen bacterias were isolated. In patients with PID, C. trachomatis was detected by serology in 28.3%. N. gonorrhoeae was isolated from the cervix in 23.9% and from the abdomen 17.4%. Besides it was isolated from the abdomen: M. hominis 17.3% and E. coli 15.2%. STB were isolated in 54.3% and EB in 47.8% of the patients. Bacterial association was present on the 37%. Cervix isolation of G. vaginalis and Mycoplasma were not correlated with development of PID. Cervix microbiological samples were useful to know abdomen microbic etiology. They coincide with those in the 90.9%. EB were more frequently isolated from severe salpingitis (p = 0.05) and STB from mild and moderate salpingitis (p = 0.05). Antibiotic association cured all the mild and moderate salpingitis with independence of bacterial etiology. Failure occurred in 2 diffuse peritonitis and 13/14 tubo-ovarian abscesses. Surgery used in severe salpingitis and diffuse peritonitis, principally consisted in anexectomy, peritoneal toilet and drainages. No hysterectomies were performed. Colpotomy drainage was used as a laparotomy complement or as unique drainage. Severe complications of surgery occurred in 10.5%. Failure in antibiotic treatment, surgery and complications were present with preference in PID with EB. After PID 26.5% of women had both Fallopian tubes damaged; in 39.7% tube damage was not evaluated and in 34.2% one tube rested in health. Damage did not depend of bacterial etiology. Conclusion on the necessity of adequate prevention of this disease and it should need education related to the roll of STB and standards about the IUD use.

[Identification and sensitivity of acinetobacter sp isolated from clinical specimens and hospital environment]. / Identificacion y sensibilidad de acinetobacter sp aislados en muestras clinicas y ambiente hospitalario.

One hundred thirty two strains of acinetobacter isolated between october 1989 and march 1991 at the San Juan de Dios Hospital, Santiago de Chile were included in this study. One hundred twelve isolates were obtained from patients and 20 from the hospital environment. Among the 112 clinical isolates, 108 (96.4%) were identified according to the new classification proposed by Bouvet and Grimont in 1986 as A. baumannii, and four as acinetobacter genospecies 3. The 20 strains obtained from the hospital environment corresponded to A baumannii. No differences in the activities of the antimicrobial agents were found between clinical and environmental strains of A baumannii. Imipenem was the most active antimicrobial drug against A baumannii followed in descending order by sulbactam ampicillin and ceftazidime. The other antimicrobials tested showed poor activity against these strains as revealed for the MICs 50 and 90 in the resistance range.

[Role of Actinobacillus actinomycetemcomitans in human infection]. / Rol del actinobacillus actinomycetemcomitans en infecciones humanas.

Actinobacillus actinomycetemcomitans (AA), is a cocobacillus thin and small, non motile, uncapsulate and capnophilic. AA, is: one of the species encountered in the mouth's comensal flora being able to be isolated in gingival crevices culture and oral mucosa in a 20% of the healthy population. An important number of pathogenic factors make it well equipped, to protect itself from host's defense mechanisms, and to destroy the periodontal tissue. Between the most important we find lipopolisacarides and leucotoxines which promote tisular invasion and destructive qualities of this microorganism. Since 1912, there are numerous reports of infectious process associated to it, between which we find: endocarditis in native and prothesic valve, soft tissues abscess, pneumonia, brain's abscess, urethritis, vertebral osteomielitis, thyroid's abscess, pericarditis and periodontal juvenile illness, being this one in which its isolation is more frequent. In vitro, AA is very susceptible to tetracicline. This antibiotic reaches high concentrations in gingival crevices, has significant affinity to the alveolar bone and contributes to protect the collagen. These special feature make them the election drug in periodontal disease produced by this microorganism.