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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.


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Journal ArticleDOI
TL;DR: Gentamicin was the most active antimicrobial agent, and coagulase‐negative species were most common, and the most frequently isolated species was Staph.
Abstract: Samples were collected from 148 adult cats, processed for isolation of Staphylococcus species and tested for susceptibility to penicillin G, gentamicin, oxacillin, amoxycillin, ampicillin, cephalexin and rifampin. Methicillin resistance was also determined. Ninety-eight isolates were obtained (66% of samples). Coagulase-negative species were most common, and the most frequently isolated species (37 samples) was Staph. felis. Other coagulase-negative species, such as Staph. simulans, Staph. epidermidis and Staph. saprophyticus were also isolated. Coagulase-positive species were obtained from 40 cats; the most frequent was Staph. intermedius (26 samples), followed by Staph. aureus (14 samples). Resistance to antibiotics was frequently observed, with 58.2% of the isolates showing resistance to at least one drug. Resistance to Penicillin G was observed in 49 of the 98 isolates (50%), 22 samples were resistant to oxacillin (22.4%) and 12 to rifampin (12.2%). Resistance to amoxycillin and ampicillin was very similar to that observed to Penicillin G. Gentamicin was the most active antimicrobial agent. Three MRSA (methicillin-resistant Staphylococcus aureus) were isolated, which represents 21.4% of the isolates of that species. Nineteen MRS (methicillin resistant staphylococci) were also observed, distributed among Staph. intermedius (eight), Staph. simulans (six) and Staph. felis (five) isolates. The role of these micro-organisms on the skin of cats is discussed.

106 citations

Journal ArticleDOI
TL;DR: An analysis of macrolide consumption data during the study period showed that erythromycin resistance was highly correlated to the consumption of newer bd and od macrolides, which belonged to the erm(B) and mef types of resistance.
Abstract: Continuous nationwide surveillance of antibiotic resistance in invasive pneumococcal disease was performed in Germany between 1992 and 2000, with a total of 2586 strains being isolated. The average resistance rates to erythromycin and clindamycin were 7.7% and 3.5%, respectively, throughout the study period; 3.3% of strains were found to have intermediate resistance to penicillin. Over the study period an increase in both macrolide and penicillin resistance was observed. The percentage of strains exhibiting reduced susceptibility to penicillin increased from 1.8% in 1992 to 5.8% in 2000. A dramatic increase in resistance was observed with erythromycin, where the resistance rate rose from 3.0% in 1992 to 15.3% in 2000. Of the erythromycin-resistant strains, 86 (43.4%) and 111 (56.1%) belonged to the erm(B) and mef types of resistance, respectively. An analysis of macrolide consumption data during the study period showed that erythromycin resistance was highly correlated to the consumption of newer bd and od macrolides (r = 0.89, P < 0.01).

106 citations

Journal ArticleDOI
TL;DR: Three penicillin-allergic patients with life-endangering infections requiring beta-lactam antibiotic therapy were desensitized by means of increasing oral then parenteral doses and were treated with full doses of beta- lactam agents, associated with antigen-specific desensitization of tissue mast cells.
Abstract: Three penicillin-allergic patients with life-endangering infections requiring beta-lactam antibiotic therapy were desensitized by means of increasing oral then parenteral doses and were treated with full doses of beta-lactam agents. Malignant otitis externa caused by Pseudomonas aeruginosa, osteomyelitis caused by Staphylococcus aureus, and bacterial endocarditis caused by an enterococcus were treated with carbenicillin, nafcillin, and benzylpenicillin G, respectively. No acute allergic reactions occurred during desensitization or within 1 wk of the onset of therapy. Immediate wheal and flare skin-test reactions to beta-lactam determinants diminished or became negative after the desensitization procedure in each patient. Wheal and flare responses provoked by histamine, compound 48/80, and environmental antigens were not affected by the desensitization procedure or continued beta-lactam drug therapy. Mild urticaria appeared after 15 days of penicillin therapy in one patient and after 23 days of carbenicillin therapy in another patient. Skin-test reactions to penicillin reagents had reverted to positive at the time of the urticarial reactions. One patient developed a severe immune hemolytic anemia after 10 days of therapy with nafcillin. The results of this study indicate that acute clinical desensitization of these three penicillin-allergic patients was associated with antigen-specific desensitization of tissue mast cells.

106 citations

Journal ArticleDOI
TL;DR: The findings suggest that tPMP-1 and HNP-1 exert anti-S.
Abstract: Thrombin-induced platelet microbicidal protein-1 (tPMP-1) and human neutrophil defensin-1 (HNP-1) are small, cationic antimicrobial peptides. These peptides exert potent in vitro microbicidal activity against a broad spectrum of human pathogens, including Staphylococcus aureus. Evidence suggests that tPMP-1 and HNP-1 target and disrupt the bacterial membrane. However, it is not yet clear whether membrane disruption itself is sufficient to kill the bacterium or whether subsequent, presumably intracellular, events are also involved in killing. We investigated the staphylocidal activities of tPMP-1 and HNP-1 in the presence or absence of pretreatment with antibiotics that differ in their mechanisms of action. The staphylocidal effects of tPMP-1 and HNP-1 on control cells (no antibiotic pretreatment) were rapid and concentration dependent. Pretreatment of S. aureus with either penicillin or vancomycin (bacterial cell wall synthesis inhibitors) significantly enhanced the anti-S. aureus effects of tPMP-1 compared with the effects against the respective control cells over the entire tPMP-1 concentration range tested (P < 0.05). Similarly, S. aureus cells pretreated with these antibiotics were more susceptible to HNP-1 than control cells, although the difference in the effects against cells that received penicillin pretreatment did not reach statistical significance (P < 0.05 for cells that received vancomycin pretreatment versus effects against control cells). Studies with isogenic pairs of strains with normal or deficient autolytic enzyme activities demonstrated that enhancement of S. aureus killing by cationic peptides and cell wall-active agents could not be ascribed to a predominant role of autolytic enzyme activation. Pretreatment of S. aureus cells with tetracycline, a 30S ribosomal subunit inhibitor, significantly decreased the staphylocidal effect of tPMP-1 over a wide peptide concentration range (0.16 to 1.25 μg/ml) (P < 0.05). Furthermore, pretreatment with novobiocin (an inhibitor of bacterial DNA gyrase subunit B) and with azithromycin, quinupristin, or dalfopristin (50S ribosomal subunit protein synthesis inhibitors) essentially blocked the S. aureus killing resulting from exposure to tPMP-1 or HNP-1 at most concentrations compared with the effects against the respective control cells (P < 0.05 for a tPMP-1 concentration range of 0.31 to 1.25 μg/ml and for an HNP-1 concentration range of 6.25 to 50 μg/ml). These findings suggest that tPMP-1 and HNP-1 exert anti-S. aureus activities through mechanisms involving both the cell membrane and intracellular targets.

106 citations

Journal ArticleDOI
TL;DR: While reports of penicillin-resistant S. pneumoniae increased worldwide through the 1980s, the high prevalence (71%) of resistance reported here is astonishing.
Abstract: Resistance (intermediate and high) to penicillin among Streptococcus pneumoniae strains is an emerging problem worldwide. From 1995 to 1997, isolates of S. pneumoniae not susceptible to penicillin were seen with increasing frequency from blood, cerebrospinal fluid, pleural fluid, and middle ear fluid from pediatric patients at the Veterans General Hospital-Kaohsiung. To determine the prevalence of carriage of these penicillin-nonsusceptible S. pneumoniae isolates, we obtained nasopharyngeal swab specimens from 2,905 children (ages, 2 months to 7 years) attending day-care centers or kindergartens or seen in our outpatient clinic. S. pneumoniae was isolated from 611 children, and 584 strains were available for analysis. The oxacillin disc test was used as a screening test to evaluate penicillin susceptibility. The MICs of 11 antibiotics (penicillin, cefaclor, cefuroxime, ceftriaxone, cefotaxime, imipenem, chloramphenicol, clarithromycin, rifampin, vancomycin, and teicoplanin) were determined by the E-test. Only 169 (29%) of the strains were susceptible to penicillin; 175 (30%) strains were intermediately resistant and 240 (41%) were highly resistant. The isolates also demonstrated high rates of resistance to other β-lactams (46% were resistant to cefaclor, 45% were resistant to cefuroxime, 45% were resistant to ceftriaxone, 31% were resistant to cefotaxime, and 46% were resistant to imipenem). The rate of resistance to macrolide antimicrobial agents was strikingly high; 95% of the isolates were not susceptible to clarithromycin. However, 97% were susceptible to rifampin and 100% were susceptible to the two glycopeptides (vancomycin and teicoplanin). While reports of penicillin-resistant S. pneumoniae increased worldwide through the 1980s, the high prevalence (71%) of resistance reported here is astonishing. Surveillance of nasopharyngeal swab specimen cultures may provide useful information on the prevalence of nonsusceptible strains causing invasive disease. Such information could be used to guide therapy of pneumococcal infections.

106 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023459
2022907
2021249
2020269
2019221
2018192