Beta-lactamic Resistance Profiles in Porphyromonas, Prevotella, and Parvimonas Species Isolated from Acute Endodontic Infections

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• 作者：Francisco Montagner ; DDS ; MSc ; PhD^&lowast ; ; ^{francisco.montagner@ufrgs.br" class="auth_mail" title="E-mail the corresponding author} ; Rogé ; rio Castilho Jacinto ; DDS ; MSc ; PhD^&dagger ; ; Fernanda Graziela Correa Signoretti ; DDS ; MSc ; PhD^&Dagger ; ; Vanessa Scheffer de Mattos ; DDS^&lowast ; ; Fabiana Soares Grecca ; DDS ; MSc ; PhD^&lowast ; ; Brenda Paula Figueiredo de Almeida Gomes ; DDS ; MSc ; PhD^&Dagger ;
• 关键词：Anaerobic bacteria ; antimicrobial agents ; E-test ; lactamases ; nitrocefin ; polymerase chain reaction ; susceptibility
• 刊名：Journal of Endodontics
• 出版年：2014
• 出版时间：March 2014
• 年：2014
• 卷：40
• 期：3
• 页码：339-344
• 全文大小：150 K

文摘

Susceptibility to beta-lactamic agents has changed among anaerobic isolates from acute endodontic infections. The aim of the present study was to determine the prevalence of the cfxA/cfxA2 gene in Prevotella spp., Porphyromonas spp., and Parviomonas micra strains and show its phenotypic expression.

Methods

Root canal samples from teeth with acute endodontic infections were collected and Porphyromonas, Prevotella, and Parvimonas micra strains were isolated and microbiologically identified with conventional culture techniques. The susceptibility of the isolates was determined by the minimum inhibitory concentration of benzylpenicillin, amoxicillin, and amoxicillin + clavulanate using the E-test method (AB BIODISK, Solna, Sweden). The presence of the cfxA/cfxA2 gene was determined through primer-specific polymerase chain reaction. The nitrocefin test was used to determine the expression of the lactamase enzyme.

Results

Prevotella disiens, Prevotella oralis, Porphyromonas gingivalis, and P. micra strains were susceptible to benzylpenicillin, amoxicillin, and amoxicillin + clavulanate. The cfxA/cfxA2 gene was detected in 2 of 29 isolates (6.9%). Simultaneous detection of the cfxA/cfxA2 gene and lactamase production was observed for 1 Prevotella buccalis strain. The gene was in 1 P. micra strain but was not expressed. Three strains were positive for lactamase production, but the cfxA/cfxA2 gene was not detected through polymerase chain reaction.

Conclusions

There is a low prevalence of the cfxA/cfxA2 gene and its expression in Porphyromonas spp., Prevotella spp., and P. micra strains isolated from acute endodontic infections. Genetic and phenotypic screening must be performed simultaneously to best describe additional mechanisms involved in lactamic resistance for strict anaerobes.