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Biomedical subjects

M F Sierra

Publications and source records attributed to M F Sierra.

At least 37 records · Page 2Linked to original sources
PubMed1982

Vaginal colonization with Group B beta-hemolytic streptococcus as a risk factor for post-cesarean section febrile morbidity.

Vaginal colonization of mothers with Group B beta-hemolytic streptococcus (GBS) has been recognized as a risk factor for neonatal morbidity. The relationship of GBS colonization to risks for the mother who undergoes cesarean section has not been defined. In this study, we found that, among patients who underwent cesarean section, the 19% of them who were colonized with GBS had a higher incidence of standard fever (66.6% vs. 30.5%), clinical diagnosis of endomyometritis (61.1% vs. 12.5%), and use of antibiotics (61.1% vs. 26.3%) in relationship to a significantly increased frequency of premature rupture of the membranes (50.0% vs. 14.8%). Reasons for the association between vaginal colonization and increased morbidity are discussed.

Anti-Bacterial Agents↗
PubMed1981

Listeria and gram-negative bacillary meningitis in New York City, 1972-1979. Frequent causes of meningitis in adults.

In an eight year period (1972-1979), 158 cases of enteric gram-negative bacillary meningitis and 53 cases of Listeria meningitis were reported to the New York City Health Department. These two forms of bacterial meningitis were the fourth and fifth most common ones reported to the Department, respectively. The cumulative total of reported cases of gram-negative rod meningitis over this less than the reported cases due to Neisseria meningitis over this period. In contrast to most previous studies of Listeria and enteric gram-negative meningitides, the majority of cases occurred in adults. Listeria meningitis occurred more often in immunosuppressed hosts and the elderly than in the newborn; gram-negative bacillary meningitides were seen more often in elderly septic patients and in patients with traumatic skull fracture than in infants during the first months of life. The over-all mortality of Listeria meningitis was 62 percent; that of the combined gram-negative meningitides 71.3 percent. The mortality in adults with Escherichia coli and Klebsiella meningitis who were treated with chloramphenicol as the major antibiotic was 83 percent. In comparison, the only appreciable survival rates noted were in those with Listeria, Escherichia coli, Proteus mirabilis and Salmonella meningitis who were treated with ampicillin alone in whom the over-all mortality was 51 percent.

Adolescent↗
PubMed1981

Survival of bacteria after freezing of human semen in liquid nitrogen.

Thirty-four semen samples from fertile men were subjected to bacteriologic evaluation before and after freezing to -196 degrees C using 10% glycerol as the protective medium. Cultures of the fresh portions from all ejaculates examined showed the presence of aerobic bacteria. Staphylococcus epidermidis, Corynebacterium sp., alpha-streptococci, and nonhemolytic streptococci were found so commonly that they were considered commensals. Enterococci, Escherichia coli, S. aureus, and beta-hemolytic streptococci group B, as well as Pseudomonas aeruginosa, P. maltophilia, and P. fluorescens, were also recovered from a few semen samples of these fertile men. Practically all bacteria isolated from the fresh ejaculate were also recovered from the portions frozen in liquid nitrogen.

Humans↗
PubMed1981

Activity of moxalactam and cefotaxime alone and in combination with ampicillin or penicillin against group B streptococci.

The activities of moxalactam and cefotaxime, alone and combined with ampicillin or penicillin, against 40 isolates of group B streptococci were assessed by using the microtiter broth dilution, checkerboard, and time-kill techniques. Penicillin and cefotaxime were bactericidal for all isolates at concentrations of 0.06 micrograms/ml or less. Ampicillin was slightly less active. Moxalactam was bactericidal for all strains at concentrations of 4 to 8 micrograms/ml. The ampicillin- moxalactam combination was partially synergistic for 60% of the isolates tested; the ampicillin-cefotaxime combination was partially synergistic for 35% of these isolates. No instances of antagonism were observed. In time-kill evaluations, ampicillin (3.0 micrograms/ml) and penicillin (0.75 micrograms/ml) effected 2.5 to 3.5 log10 reductions in numbers of colony-forming units. The addition of 4 micrograms of cefotaxime per ml or 8 to 16 micrograms of moxalactam per ml to penicillin or ampicillin did not alter killing kinetics. Moxalactam and cefotaxime neither enhanced nor decreased the activity of ampicillin or penicillin against group B streptococci.

Ampicillin↗
PubMed1981

Susceptibility of gram-positive cocci to various antibiotics, including cefotaxime, moxalactam, and N-formimidoyl thienamycin.

The activities of cefotaxime, moxalactam, MK 0787 (N-formimidoyl thienamycin), ampicillin, oxacillin, vancomycin, and clindamycin were compared against gram-positive cocci. MK 0787 was the most active and moxalactam was the least active of these drugs, except against methicillin-resistant Staphylococcus aureus, where vancomycin was most active, and penicillin-resistant pneumococci, where cefotaxime was more active.

Ampicillin↗
PubMed1981

In vitro susceptibility of Campylobacter fetus subsp. jejuni to N-formimidoyl thienamycin, rosaramicin, cefoperazone, and other antimicrobial agents.

The activities of 11 antimicrobial agents against 36 strains of Campylobacter fetus subsp. jejuni were studied by a broth microdilution method. All strains were susceptible to 7 of the 11 antimicrobial agents. Of the newer agents tested N-formimidoyl thienamycin (MK0787) and rosaramicin had very good activity, whereas cefotaxime, moxalactam, and cefoperazone had poorer activity.

Animals↗
PubMed1980

A sudden decline in ampicillin resistance in Salmonella typhimurium.

Starting in 1975, an abrupt decline in ampicillin resistance of Salmonella typhimurium (the most common and antibiotic-resistant serotype) occurred in New York City. The present lower rate of 5% to 7.9% at our hospitals represents a return to the 1965 level. At the same time, the ampicillin resistance in S typhimurium from calves and other farm animals from upper New York State, which has been rising since 1972, has reached 75%. Substantial differences between levels of resistance in Escherichia coli from animals and humans were also noted. The divergence of the trends in S typhimurium from these two sources in New York State suggests a substantial degree of separation of the respective reservoirs of Salmonella and of antibiotic resistance.

Ampicillin↗
PubMed1980

Source of Pseudomonas in osteomyelitis of heels.

Pseudomonas aeruginosa is the most common cause of osteomyelitis following puncture wounds of the feet of children. The source of the initial inoculum is unknown. Only one strain of P. aeruginosa was cultured from paired samples of the heel or corresponding shoe's surface or both obtained from 100 children. Neither the skin of the heel nor the shoe appears to be the source of the initial inoculum.

Adolescent↗
PubMed1979

Listeria monocytogenes: brain abscess or meningoencephalitis?

A brain abscess caused by Listeria monocytogenes developed in an immunosuppressed renal transplant patient. Meningitis and meningoencephalitis from this organism were encountered in three other renal transplant recipients at this medical center during the past 4 years. Focal neurologic deficits occurred in patients with either Listeria abscess or meningoencephalitis. Computerized tomography was a rapid aid to the diagnosis of abscess. Immunosuppression has increased the incidence of central nervous system Listeria infections, but ampicillin still provides effective treatment, even when immunosuppressive therapy is continued. Limited experience with Listeria brain abscess suggests that surgical intervention improves the prognosis.

Adult↗
PubMed1975

Primary pulmonary sporotrichosis complicated by perirectal abscess.

A 48-year old, retired mounted policeman was followed for 4 years through 4 hospitalizations for progression of his bilateral, cavitary lung disease. His sputum was always negative for acid-fast bacilli and fungi. Subsequently, a painful perianal swelling appeared that was incised and drained of purulent material. Five years after first seen, sputum and rectal drainage revealed Sporothrichum schenckii in many cultures. Serologic evidence of sporotrichosis was also present. With amphotericin B therapy, the patient showed marked clinical improvement. Unfortunately, he died from an episode of acute respiratory failure. Although most patients with primary cutaneous or primary pulmonary sporotrichosis are horticulturists, the writers believe that this disease should be considered in any undiagnosed, chronic, cavitary lung disease, even in the absence of this occupational history.

Abscess↗
PubMed1973

Assembly of the mitochondrial system. Purification of a mitochondrial product of the ATPase.

A low-molecular-weight protein synthesized in yeast mitochondria was purified. The protein was identified as a component of the rutamycin-sensitive ATPase. The amino-acid composition of the purified protein shows an extremely large preponderance of nonpolar residues, which may account for its solubility in chloroform-methanol. Indirect evidence suggests that this component is involved in the conferral of rutamycin sensitivity and may also have a function in the assembly of the ATPase complex.

Adenosine Triphosphatases↗