ABSTRACT
Data on methicillin-resistant Staphylococcus aureus have not been presented before in Argentina. Due to non adequate microbiologic techniques, this phenomenon may be overlooked. Heterogeneous strains are only detected with 5% NaCl agar, low temperature (30 degrees C) or prolonged incubation and/or high inocula (10(6) C.F.U.). Minimal inhibitory concentrations (MICs) of methicillin were studied by the agar dilution technique in antibiotic medium number 4 with and without 5% salt. This study was performed for 107 strains at 37 degrees C, after 24 and 48 h incubation, with an inoculum size of 10(6) CFU. S. aureus strains were considered resistant whenever MICs were greater than or equal to 8 mg/l. Forty seven (44%) methicillin-resistant strains were detected. Thirty one were high level resistant mutants and sixteen showed the heterogeneous phenomenon. Due to the high frequency of resistant strains among clinical specimens in this country, the routine use of elaborate screening tests with special media and or prolonged incubation time is justified.
Subject(s)
Methicillin/pharmacology , Argentina , Bacteriological Techniques , Humans , Penicillin Resistance , Staphylococcal Infections/microbiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purificationABSTRACT
In a 4 year prospective study of "viridans" or non-groupable streptococci 100 clinically significant strains were isolated. Strains were defined as significant when found in two or more samples of blood cultures, or when seen on Gram staining together with inflammatory reaction. Fifty-two strains were speciated by 10 physiological characteristics. In 42 cases additional tests were performed. Only 16 isolates were unidentifiable by the techniques used. Sources of isolates included purulent lesions (53%) (mainly S. milleri and S. mitior); endocarditis (27%) (S. bovis I, S. sanguis, S. mutans, S. bovis II) and urinary tract infections (10%) (S. bovis II, S. milleri).
Subject(s)
Streptococcal Infections/microbiology , Streptococcus/classification , Endocarditis, Bacterial/microbiology , Humans , Prospective Studies , Streptococcus/isolation & purificationSubject(s)
Dysentery, Bacillary/complications , Sepsis/etiology , Aged , Female , Humans , Middle Aged , Shigella sonneiABSTRACT
The study of anaerobic bacteria became important in Argentina when the first outbreak of botulism was reported in Mendoza in 1922. In the 1970s, the emphasis was on the development of methods to obtain suitable samples for isolation and identification of anaerobic bacteria. In 1985, a working group belonging to the Argentine Association of Microbiology was organized to study anaerobic bacteria and infections. Last year, I became involved with the immunologic, microbiological, and epidemiological features of periodontitis. Other investigators in our country are studying Clostridium difficile, Campylobacter species, and Helicobacter species as well as lactobacilli, Propionibacterium species (as probiotics to protect the gastrointestinal tracts of children), anaerobic veterinary infections, food contamination by anaerobes, and biotechnological applications of anaerobes.
Subject(s)
Bacteria, Anaerobic/isolation & purification , Bacterial Infections/diagnosis , Botulism/epidemiology , Argentina/epidemiology , Bacteria, Anaerobic/drug effects , HumansABSTRACT
Synergy of 14 Enterococcus faecalis strains displaying moderately high-level aminoglycoside resistance (MICs, 500 and 256 to 1,000 micrograms/ml for gentamicin and streptomycin, respectively) was characterized by time-kill studies. All strains proved resistant to penicillin plus the respective aminoglycoside. Strains with moderately high-level aminoglycoside resistance should be considered to exhibit high-level resistance in severe infections.
Subject(s)
Enterococcus faecalis/drug effects , Gentamicins/pharmacology , Streptomycin/pharmacology , Drug Resistance, Microbial , Drug Synergism , Drug Therapy, Combination/administration & dosage , Enterococcus faecalis/isolation & purification , Gentamicins/administration & dosage , Gram-Positive Bacterial Infections/drug therapy , Humans , Microbial Sensitivity Tests , Penicillin Resistance , Streptomycin/administration & dosageABSTRACT
We describe an 18-year-old man with a renal transplant who developed septic metacarpophalangeal arthritis due to Mycobacterium gastri. He had several episodes of crystal induced synovitis, and treatment with intraarticular steroids was complicated 3 months later by iatrogenic septic arthritis. Appropriate treatment based on in vitro drug susceptibility was successful. This seems to be the first case of articular infection and the third report of human infection caused by this atypical mycobacteria.
Subject(s)
Arthritis, Infectious/etiology , Kidney Transplantation/adverse effects , Mycobacterium Infections, Nontuberculous , Adolescent , Arthritis, Infectious/pathology , Humans , Male , Metacarpophalangeal Joint/microbiology , Metacarpophalangeal Joint/pathologyABSTRACT
Several isolates of vancomycin-resistant Lactobacillus confusus from human sources have been described, but to our knowledge, no well-documented infection attributable to this organism has been published. A thumb abscess caused by this bacterium in a healthy 49-year-old male is reported here. He was successfully treated by surgical drainage and cephalothin.
Subject(s)
Abscess/etiology , Bacterial Infections/etiology , Lactobacillus/pathogenicity , Abscess/drug therapy , Abscess/surgery , Bacterial Infections/drug therapy , Bacterial Infections/surgery , Cephalothin/therapeutic use , Drug Resistance, Microbial , Humans , Lactobacillus/drug effects , Male , Middle Aged , Thumb , Vancomycin/pharmacologyABSTRACT
Con el fin de evaluar un esquema de pruebas bioquímicas para identificar estreptococos del grupo "viridans" y S. bovis, se tipificaron 110 cepas aisladas de materiales clínicos. El 74,5 por ciento fue identificado con criterio de coincidencia absoluta con el esquema utilizado, el 17,3 por ciento se tipificó admitiendo 1 reacción atípica y el 8,2 por ciento fue nominado como estreptococos, puesto que no pudieron ser incluidos en ninguno de los dos casos anteriores. Las especies que más frecuentemente mostraron una reacción atípica, fueron S. mitis (7/22 cepas), S. anginosus (S. milleri) (6/16 cepas) y S. sanguis (3/16 cepas). Del total de cepas de S. sanguis, S. mutans y S. bovis I, aisladas se hemocultivo, el 86 por ciento estuvo asociado a Endocarditis Infecciosa. La capacidad para producir dextrán en las cepas aisladas de hemocultivo, se asoció a la presencia de esta patología, con valores predictivos positivo y negativo de 86 por ciento y 94 por ciento, respectivamente. S. anginosus (S. milleri) se aisló de abscesos más frecuentemente que las otras especies. Consideramos que debido a la transcendencia clínica que tiene actualmente la correcta identificación a nivel de especie de estos microorganismos, el esquema propuesto constituye una alternativa útil para tal fin, en los laboratorios de Bacteriología Clínica de nuestro medio
Subject(s)
Humans , Bacterial Typing Techniques/instrumentation , Streptococcal Infections/diagnosis , Streptococcus bovis/isolation & purification , Streptococcus mutans/isolation & purification , Streptococcus sanguis/isolation & purification , Bacterial Typing Techniques/standards , Bacterial Typing Techniques/statistics & numerical data , Dextrans , Endocarditis, Bacterial/microbiology , Streptococcal Infections/microbiology , Streptococcus/classification , Streptococcus/isolation & purificationABSTRACT
Streptococcus bovis comparte muchas características bioquímicas con algunas especies del grupo "viridans". En ese sentido, algunas de éstas son capaces de dar positiva la prueba de bilis-esculina (BE+). Debido a la implicancia clínica que tiene la correcta diferenciación de estos microorganismos, se estudió su incidencia en materiales clínicos y se evaluó una marcha mínima de pruebas bioquímicas para su identificación. Sobre 172 aislamientos sucesivos, tipificados según un esquema descripto previamente por los autores, se encontraron 59 cepas (34 por ciento) BE+, 23 (13 por ciento) fueron S. bovis y 36 (21 por ciento) fueron especies del grupo "viridans". La distribución de cepas BE+ dentro de las mismas fue: S. anginosus, 22 por ciento (9/41), S. sanguis, 26 por ciento (6/23), S. mutans, 72 por ciento (13/18), S. vestibularis 4/7 y S. salivarius 4/6 cepas. El 41 por ciento de las 59 cepas BE+ se aisló de hemocultivos. El esquema propuesto identificó correctamente todas las cepas BE+. Utilizando sólo las pruebas de bilis-esculina y desarrollo en caldo CINa (6,5 por ciento), se cometería un error del 60 por ciento en la identificación presuntiva de S. bovis. Creemos que este estudio sugiere la necesidad de incluir pruebas adicionales a las de identificación presuntiva de este microorganismo. Considerando la comprobada asociación de S. bovis con patología gastrointestinal, el esquema propuesto podría ser de interés para el laboratorio de bacteriología clínica, ya que permite llegar al nivel de especie con bajo riesgo de error
Subject(s)
Humans , Bile , Endocarditis, Bacterial/microbiology , Esculin , Streptococcus bovis/isolation & purification , Bacteriological Techniques/standards , Culture Media , Endocarditis, Bacterial/etiology , Polysaccharides , Streptococcus/classification , Microbiological Techniques/standards , Microbiological TechniquesABSTRACT
Data on methicillin-resistant Staphylococcus aureus have not been presented before in Argentina. Due to non adequate microbiologic techniques, this phenomenon may be overlooked. Heterogeneous strains are only detected with 5
NaCl agar, low temperature (30 degrees C) or prolonged incubation and/or high inocula (10(6) C.F.U.). Minimal inhibitory concentrations (MICs) of methicillin were studied by the agar dilution technique in antibiotic medium number 4 with and without 5
salt. This study was performed for 107 strains at 37 degrees C, after 24 and 48 h incubation, with an inoculum size of 10(6) CFU. S. aureus strains were considered resistant whenever MICs were greater than or equal to 8 mg/l. Forty seven (44
) methicillin-resistant strains were detected. Thirty one were high level resistant mutants and sixteen showed the heterogeneous phenomenon. Due to the high frequency of resistant strains among clinical specimens in this country, the routine use of elaborate screening tests with special media and or prolonged incubation time is justified.
ABSTRACT
Se revisaron retrospectivamente las historias clínicas de 9 casos de listeriosis atendidos en CEMIC en los últimos 15 años, ocho de los cuales fueron observados en enfermos con patología y/o tratamientos capaces de deprimir la inmunidad celular (LES, dermatopolimiositis, transplante renal, hemodiálisis crónica, carcinomatosis y linfoma histiocítico). Una enferma de 62 años no presentó ninguna patología de base. Se observarón 6 meningitis y 3 sepsis sin compromiso neurológico. Siete de las nueve cepas aisladas correspondieron al serotipo I, prevalente en el ganado bovino argentino. Las 9 cepas resultaron sensibles a ampicilina, tobramicina, amikacina y cloramfenicol. Siete enfermos curaron sin secuelas
Subject(s)
Adult , Middle Aged , Humans , Male , Female , Listeriosis/diagnosis , Anti-Bacterial Agents/pharmacology , Listeria monocytogenes/drug effects , Microbial Sensitivity Tests , Retrospective StudiesABSTRACT
Se realizó un estudio prospectivo durante 4 años de cepas de estreptococos "viridans" o no agrupables. Se estudiaron 100 cepas clínicamente significativas aisladas de hemocultivos (dos o más muestras) y de otros materiales clínicos (cuando se visualizaban al exame directo, en presencia de reacción inflamatória). Cincuenta y ocho cepas fueron identificadas con 10 reacciones bioquímicas y en 42 fue necesario realizar determinaciones adicionales. Solamente 16 cepas resultaron no identificables. Los setreptococos aislados correspondieron a infecciones piógenas (53%) (en especial S. milleri y S. mitior); endocarditis (27%) (S.bovis I. S. sanguis, S. mutans y S. bovis II); infecciones urinarias (10%) (S. bovis II, S. milleri)