Use of Gentamicin in the Isolation of Subgroup A Chlamydia

contrasting

confidence: 49%

Antibiotic Susceptibilities of Parachlamydia acanthamoeba in Amoebae

Maurin

Bryskier²,

Raoult

2002

“…The satisfactory use of gentamicin in the treatment ofdiagnostic specimens submitted for virus isolation has been reported by several investigators (9,10,12). However, our results indicate that gentamicin should not be used in diagnostic specimens collected for the isolation of rickettsiae.…”

Section: Methodscontrasting

confidence: 43%

“…This may be the maximum tolerance level for LGV, since lower concentrations were used without adverse effects. Wentworth (12) To some degree, all of the rickettsial agents were susceptible to gentamicin at or above the 50 ,ug/ml level. However, no reduction in infectivity other than that shown with R. akari was observed at the 5 ,ug/ml concentration.…”

Section: Methodsmentioning

confidence: 99%

“…The routine recommended dose of50 ,ug/ ml in cell cultures was found to be bactericidal for a wide range of organisms. Wentworth (12) described the use of 10 ,ug of gentamicin per ml for the isolation in McCoy cell cultures of subgroup A Chlamydia from clinical specimens. Acute and subacute toxicity studies conducted in mice by Black et al (1) revealed that the lethal dose of gentamicin sulfate administered by parenteral routes exceeded 400 mg/kg of body weight.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Effect of Gentamicin on Growth of Viral, Chlamydial, and Rickettsial Agents in Mice and Embryonated Eggs

La¹,

He²,

Tzianabos³

et al. 1976

Gentamicin, at concentrations up to 500 ,g/ml, showed no effect on the replication, yield, or infectivity of seven viruses or on the agents of psittacosis and men-ngopneumonitis when grown in mice or embryonated eggs. At the 500 ,ug/ml level, lymphogranuloma venereum cultures had a slight reduction in infectivity. Rickettsia akari demonstrated susceptibility at the 5 ug/ml level, whereas R. rickettsii, R. mooseri, and R. canada grown in embryonated eggs were susceptible in varying degrees to gentamicin at or above the 50 ,ug/ml concentration.Gentamicin sulfate, an aminoglycoside antibiotic, is readily soluble in water, autoclavable, and highly stable at wide pH and temperature ranges. It has been reported (4,6,11) to inhibit the in vitro growth of a wide range of grampositive and gram-negative bacteria. Other investigators (5, 7) have described the effectiveness of gentamicin in eliminating mycoplasmas from cell cultures. Its use in virological studies with cell cultures as reported by Schafer et al. (10) showed neither cytotoxic effects nor virucidal activity at concentrations as high as 2,000 ,ug/ml. The routine recommended dose of50 ,ug/ ml in cell cultures was found to be bactericidal for a wide range of organisms. Wentworth (12) described the use of 10 ,ug of gentamicin per ml for the isolation in McCoy cell cultures of subgroup A Chlamydia from clinical specimens. Acute and subacute toxicity studies conducted in mice by Black et al. (1) revealed that the lethal dose of gentamicin sulfate administered by parenteral routes exceeded 400 mg/kg of body weight.These reports led us to consider applying gentamicin in the large-scale production of viral, chlamydial, and rickettsial diagnostic reagents from fluids and tissues of mice and embryonated chicken eggs. Penicillin and streptomycin are routinely used to control contamination in the production of viral reagents; however, these antibiotics cannot be used in the production ofchlamydial and rickettsial reagents. The purpose of this report is to describe the effect of gentamicin on the replication of several viral, rickettsial, and chlamydial agents in mice and embryonated eggs. The chlamydial agents included were those of psittacosis, strain DD-34; meningopneumonitis, strain Francis; and lymphogranuloma venereum, strain JH. MATERIALS AND METHODS Organisms. The viruses included in these investiThe four rickettsiae included were Rickettsia akari, strain Hartford; R. rickettsii, strain Shelia Smith; R. mooseri, strain Wilmington; and R. canada.Host systems. Embryonated eggs were obtained from chicken flocks maintained on antibiotic-free feed. The viral agents and psittacosis were grown in the allantoic cavity of either 8-or 10-day-old eggs incubated at 33 to 35°C. The other chlamydiae were grown in the yolk sacs of 8-day-old eggs incubated at 36°C. The rickettsial agents were cultivated in the yolk sacs of 5-to 6-day-old eggs at 35°C.Random-bred, ICR, weanling mice weighing approximately 15 to 18 g were inoculated intracranially with 0.03 ml of rabies, psittaco...

“…Although aminoglycosides are effective against many bacterial pathogens, they exert poor to no activity in treating intracellular bacterial infections caused by Chlamydia species (2,3), Staphylococcus aureus (4), Legionella pneumophila (5), and Salmonella enterica (6). To overcome this intrinsic problem, many approaches to increase the entry of aminoglycosides into host cells, including the use of liposomal (7) and chitosan (8) encapsulations, have been proposed.…”

mentioning

confidence: 99%

Sensitization of Intracellular Salmonella enterica Serovar Typhimurium to Aminoglycosides In Vitro and In Vivo by a Host-Targeted Antimicrobial Agent

Kulp

Chen

et al. 2014

c Aminoglycosides exhibit relatively poor activity against intracellular Salmonella enterica serovar Typhimurium due to their low permeativity across eukaryotic cell membranes. Previously, we identified the unique ability of AR-12, a celecoxib-derived smallmolecule agent, to eradicate intracellular Salmonella Typhimurium in macrophages by facilitating autophagosome formation and suppressing Akt kinase signaling. In light of this unique mode of antibacterial action, we investigated the ability of AR-12 to sensitize intracellular Salmonella to aminoglycosides in macrophages and in an animal model. The antibacterial activities of AR-12 combined with various aminoglycosides, including streptomycin, kanamycin, gentamicin, and amikacin, against intracellular S. Typhimurium in murine RAW264.7 macrophages were assessed. Cells were infected with S. Typhimurium followed by treatment with AR-12 or individual aminoglycosides or with combinations for 24 h. The in vivo efficacies of AR-12, alone or in combination with gentamicin or amikacin, were also assessed by treating S. Typhimurium-infected BALB/c mice daily for 14 consecutive days. Exposure of S. Typhimurium-infected RAW264.7 cells to a combination of AR-12 with individual aminoglycosides led to a reduction in bacterial survival (P < 0.05), both intracellular and extracellular, that was greater than that seen with the aminoglycosides alone. This sensitizing effect, however, was not associated with increased aminoglycoside penetration into bacteria or macrophages. Moreover, daily intraperitoneal injection of AR-12 at 0.1 mg/kg of body weight significantly increased the in vivo efficacy of gentamicin and amikacin in prolonging the survival of S. Typhimurium-infected mice. These findings indicate that the unique ability of AR-12 to enhance the in vivo efficacy of aminoglycosides might have translational potential for efforts to develop novel strategies for the treatment of salmonellosis.