A TolC-Like Protein ofActinobacillus pleuropneumoniaeIs Involved in Antibiotic Resistance and Biofilm Formation.
Actinobacillus pleuropneumoniaeis the etiologic agent of porcine contagious pleuropneumonia, a significant disease that causes serious economic losses to the swine industry worldwide. Persistent infections caused by bacterial biofilms are recalcitrant to treat because of the particular drug resistance of biofilm-dwelling cells. TolC, a key component of multidrug eﬄux pumps, are responsible for multidrug resistance (MDR) in many Gram-negative bacteria. In this study, we identified two TolC-like proteins, TolC1 and TolC2, inA. pleuropneumoniae.Deletion oftolC1, but nottolC2, caused a significant reduction in biofilm formation, as well as increased drug sensitivity of both planktonic and biofilm cells. The genetic-complementation of thetolC1mutation restored the competent biofilm and drug resistance. Besides, biofilm formation was inhibited and drug sensitivity was increased by the addition of phenylalanine-arginine beta-naphthylamide (PAβN), a well-known eﬄux pump inhibitor (EPI), suggesting a role for EPI in antibacterial strategies toward drug tolerance ofA. pleuropneumoniae. Taken together, TolC1 is required for biofilm formation and is a part of the MDR machinery of both planktonic and biofilm cells, which could supplement therapeutic strategies for resistant bacteria and biofilm-related infections ofA. pleuropneumoniaeclinical isolate SC1516.
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Ying
Y
Li
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Sanjie
S
Cao
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China; Department of Pathobiology, University of Illinois at Urbana-ChampaignUrbana, IL, USA.
Luhua
L
Zhang
Department of Pathobiology, University of Illinois at Urbana-Champaign Urbana, IL, USA.
Gee W
GW
Lau
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Yiping
Y
Wen
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Rui
R
Wu
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Qin
Q
Zhao
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Xiaobo
X
Huang
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Qigui
Q
Yan
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Yong
Y
Huang
Research Center of Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural University Chengdu, China.
Xintian
X
Wen
Actinobacillus pleuropneumoniae; PAβN; TolC; biofilm formation; multidrug resistance