Penicillin

About: Penicillin is a research topic. Over the lifetime, 17916 publications have been published within this topic receiving 368480 citations. The topic is also known as: penicillin antibiotic & PCN.

Mechanistic Study of the Synergistic Antibacterial Activity of Combined Silver Nanoparticles and Common Antibiotics

Abstract: A combination of silver nanoparticles (AgNPs) and an antibiotic can synergistically inhibit bacterial growth, especially against the drug-resistant bacteria Salmonella typhimurium. However, the mechanism for the synergistic activity is not known. This study chooses four classes of antibiotics, β-lactam (ampicillin and penicillin), quinolone (enoxacin), aminoglycoside (kanamycin and neomycin), and polykeptide (tetracycline) to explore their synergistic mechanism when combined with AgNPs against the multidrug-resistant bacterium Salmonella typhimurium DT 104. Enoxacin, kanamycin, neomycin, and tetracycline show synergistic growth inhibition against the Salmonella bacteria when combined with AgNPs, while ampicillin and penicillin do not. UV–vis and Raman spectroscopy studies reveal that all these four synergistic antibiotics can form complexes with AgNPs, while ampicillin and penicillin do not. The presence of tetracycline enhances the binding of Ag to Salmonella by 21% and Ag+ release by 26% in comparison t...

Streptococcus pneumoniae: epidemiology, risk factors, and clinical features.

Abstract: Streptococcus pneumoniae is the most common cause of both pneumonia overall and fatal pneumonia. Antibiotic resistance has developed worldwide and is most frequent in pneumococcal serotypes that are most prevalent in children (types/groups 6, 14, 19, and 23). The incidence of pneumococcal disease is the highest in children 65 years of age. Other important risk factors are chronic heart and lung disease, cigarette smoking, and asplenia. A 23-valent capsular polysaccharide vaccine and a heptavalent protein-polysaccharide conjugate vaccine are currently available. The latter is specially designed for pediatric use because small children respond poorly to polysaccharide antigens. Both vaccines are efficacious in prevention of invasive pneumococcal disease. The clinical presentation of pneumococcal pneumonia is variable, and neither clinical features nor laboratory or radiographic findings can reliably predict the etiology of pneumonia. Blood culture is the most important tool for establishing a definitive diagnosis, but Gram's stains and sputum culture are also of value in skilled hands. A recently developed urinary antigen test may provide a rapid diagnosis of pneumococcal pneumonia in adults. Penicillin (penicillin G/amoxicillin) remains the drug of choice for strains that are fully sensitive or have a moderately decreased susceptibility to penicillin, whereas cefotaxime and ceftriaxone are the first-line alternatives in cases with higher levels of resistance.

Penicillin allergy: clinical experience with a battery of skin-test reagents.

Abstract: From 1971 through August 1978, 778 patients underwent penicillin skin testing. Each patient gave a history of previous penicillin allergy. The skin-test reagents consisted of (1) fresh solutions of commercially prepared penicillin G (PEN G), ampicillin (AMP), and methicillin (METH); (2) polylysine conjugates of the major antigenic determinants of each of the three drugs; and (3) alkaline hydrolysates of each drug. A total of 108 (14%) patients showed positive reactions to one or more of the reagents. Certain patients showed reactivity to many reagents, whereas others reacted selectively to only one or two reagents. Addition of reagents of AMP and METH resulted in a greater number of positive reactors than when reagents of PEN G alone were used. Of the group whose skin tests were negative, 290 (43%) were later treated with a penicillin, twelve of these (4.1%) had allergic reactions. Eight of the group whose skin tests were positive were subsequently treated, and four of these (50%) had allergic reactions again. A group of 151 patients whose skin tests were negative and 27 patients whose skin tests were positive were treated with a cephalosporin. Only two patients had allergic reactions to the drug; both had had negative skin tests to penicillin. We conclude that the risk of subsequent allergic reactivity to penicillin is much lower if the skin tests are negative than if positive, that testing with semisynthetic penicillins increases the number of skin-test reactors, and that the incidence of allergic reactions is low in patients treated with a cephalosporin.