鲍氏不動桿菌(Acinetobacter baumannii)與許多醫院的院內感染有關，例如呼吸器相關肺炎及菌血症。sulbactam，一種β-内酰胺酶(β-lactamase)的抑制劑，通常會和β-内酰胺類(β-lactam)的抗生素一起使用來治療感染。過去曾經發現sulbactam單獨使用就能夠治療由鲍氏不動桿菌所引起的感染。但是sulbactam的殺菌機轉仍不清楚。我們利用蛋白質體學來分析並定義鲍氏不動桿菌在經過sulbactam處理後菌內蛋白質強度的改變，發現其中有54個蛋白質的強度有顯著的改變。減少強度的蛋白質包含ABC transporters、30s、50s ribosomal subunit proteins，這些蛋白質是細菌生存所必須的，其功能是調控營養的輸入及細菌內蛋白質的合成。而增加強度的蛋白質則包含glutamine synthetase、malic enzyme、RNA polymerase subunit α、以及molecular chaperone DnaK and GroEL。這些蛋白質與代謝、DNA及蛋白質的合成、修復系統等功能相關。然而，即使細菌增加這些蛋白質想藉此生存，卻無法戰勝減少的蛋白質所造成的傷害，最終導致細菌死亡。這是第一篇研究指出sulbactam對鲍氏不動桿菌的殺菌機轉是藉由減少ABC transporters以及30s、50s ribosomal subunit proteins的表現而達成的。

Acinetobacter baumannii has been associated with several severe hospital-acquired infections such as ventilator-associated pneumonia and meningitis. Sulbactam, a β-lactamase inhibitor, is usually combined with β-lactam antibiotics to treat infections. It has been found that sulbactam alone could be used to treat infections caused by A. baumannii. The mechanism of bacteticidal effect of sulbactam remains unknown. Proteomics was used to analyze protein intensity changes and identify the proteins of A. baumannii after sulbactam treatment. There were 54 proteins found to exhibit significant changes in intensity. The reduced proteins include adenosine triphosphate-binding cassette (ABC) transporters, and 30s, 50s ribosomal subunit proteins. These proteins are essential for nutrient import and protein syntheses and are vital for bacterial survival. The amplified proteins include glutamine synthetase, malic enzyme, RNA polymerase subunit α, and molecular chaperone DnaK and GroEL. They function in metabolism, DNA and protein syntheses, and repair machinery. These amplified proteins were increased for rescuing bacteria. However, their increases could not overcome the effects of the reduced proteins and the bacteria killed. This is the first report that the reduction of ABC transporters and the 30s, 50s ribosomal subunit proteins plays an important role for the bactericidal effect of sulbactam against A. baumannii.

(1) Nemec, A.; Musilek, M.; Maixnerova, M.; De Baere, T.; van der Reijden, T. J.; Vaneechoutte, M.; Dijkshoorn, L. Acinetobacter beijerinckii sp. nov. and Acinetobacter gyllenbergii sp. nov., haemolytic organisms isolated from humans. International journal of systematic and evolutionary microbiology 2009, 59, 118-124.
(2) Bergogne-Berezin, E.; Towner, K. J. Acinetobacter spp. as nosocomial pathogens: microbiological, clinical, and epidemiological features. Clinical microbiology reviews 1996, 9, 148-165.
(3) Dijkshoorn, L.; Nemec, A.; Seifert, H. An increasing threat in hospitals: multidrug-resistant Acinetobacter baumannii. Nature reviews. Microbiology 2007, 5, 939-951.
(4) Kramer, A.; Schwebke, I.; Kampf, G. How long do nosocomial pathogens persist on inanimate surfaces? A systematic review. BMC infectious diseases 2006, 6, 130.
(5) Rajamohan, G.; Srinivasan, V. B.; Gebreyes, W. A. Biocide-tolerant multidrug-resistant Acinetobacter baumannii clinical strains are associated with higher biofilm formation. The Journal of hospital infection 2009, 73, 287-289.
(6) Gaynes, R.; Edwards, J. R.; National Nosocomial Infections Surveillance, S. Overview of nosocomial infections caused by gram-negative bacilli. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2005, 41, 848-854.
(7) Joly-Guillou, M. L. Clinical impact and pathogenicity of Acinetobacter. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases 2005, 11, 868-873.
(8) Waxman, D. J.; Strominger, J. L. Penicillin-binding proteins and the mechanism of action of beta-lactam antibiotics. Annual review of biochemistry 1983, 52, 825-869.
(9) Waxman, D. J.; Strominger, J. L. Sequence of active site peptides from the penicillin-sensitive D-alanine carboxypeptidase of Bacillus subtilis. Mechanism of penicillin action and sequence homology to beta-lactamases. The Journal of biological chemistry 1980, 255, 3964-3976.
(10) Yocum, R. R.; Rasmussen, J. R.; Strominger, J. L. The mechanism of action of penicillin. Penicillin acylates the active site of Bacillus stearothermophilus D-alanine carboxypeptidase. The Journal of biological chemistry 1980, 255, 3977-3986.
(11) Wise, E. M., Jr.; Park, J. T. Penicillin: its basic site of action as an inhibitor of a peptide cross-linking reaction in cell wall mucopeptide synthesis. Proceedings of the National Academy of Sciences of the United States of America 1965, 54, 75-81.
(12) Tipper, D. J.; Strominger, J. L. Mechanism of action of penicillins: a proposal based on their structural similarity to acyl-D-alanyl-D-alanine. Proceedings of the National Academy of Sciences of the United States of America 1965, 54, 1133-1141.
(13) Fournier, P. E.; Vallenet, D.; Barbe, V.; Audic, S.; Ogata, H.; Poirel, L.; Richet, H.; Robert, C.; Mangenot, S.; Abergel, C.; Nordmann, P.; Weissenbach, J.; Raoult, D.; Claverie, J. M. Comparative genomics of multidrug resistance in Acinetobacter baumannii. PLoS genetics 2006, 2, e7.
(14) Maragakis, L. L.; Perl, T. M. Acinetobacter baumannii: epidemiology, antimicrobial resistance, and treatment options. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2008, 46, 1254-1263.
(15) Siroy, A.; Cosette, P.; Seyer, D.; Lemaitre-Guillier, C.; Vallenet, D.; Van Dorsselaer, A.; Boyer-Mariotte, S.; Jouenne, T.; De, E. Global comparison of the membrane subproteomes between a multidrug-resistant Acinetobacter baumannii strain and a reference strain. Journal of proteome research 2006, 5, 3385-3398.
(16) Heritier, C.; Poirel, L.; Lambert, T.; Nordmann, P. Contribution of acquired carbapenem-hydrolyzing oxacillinases to carbapenem resistance in Acinetobacter baumannii. Antimicrobial agents and chemotherapy 2005, 49, 3198-3202.
(17) Higgins, P. G.; Wisplinghoff, H.; Stefanik, D.; Seifert, H. Selection of topoisomerase mutations and overexpression of adeB mRNA transcripts during an outbreak of Acinetobacter baumannii. The Journal of antimicrobial chemotherapy 2004, 54, 821-823.
(18) Callie Camps, O. L. T. A Review of Acinetobacter baumannii as a Highly Successful Pathogen in Times of War. Labmedicine 2010, 41, 649-657.
(19) Williams, J. D. beta-Lactamase inhibition and in vitro activity of sulbactam and sulbactam/cefoperazone. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 1997, 24, 494-497.
(20) Rafailidis, P. I.; Ioannidou, E. N.; Falagas, M. E. Ampicillin/sulbactam: current status in severe bacterial infections. Drugs 2007, 67, 1829-1849.
(21) Sandanayaka, V. P.; Prashad, A. S. Resistance to beta-lactam antibiotics: structure and mechanism based design of beta-lactamase inhibitors. Current medicinal chemistry 2002, 9, 1145-1165.
(22) Lilley, K. S.; Razzaq, A.; Dupree, P. Two-dimensional gel electrophoresis: recent advances in sample preparation, detection and quantitation. Current opinion in chemical biology 2002, 6, 46-50.
(23) Von Eggeling, F.; Gawriljuk, A.; Fiedler, W.; Ernst, G.; Claussen, U.; Klose, J.; Romer, I. Fluorescent dual colour 2D-protein gel electrophoresis for rapid detection of differences in protein pattern with standard image analysis software. International journal of molecular medicine 2001, 8, 373-377.
(24) Hsueh, P. R.; Teng, L. J.; Chen, C. Y.; Chen, W. H.; Yu, C. J.; Ho, S. W.; Luh, K. T. Pandrug-resistant Acinetobacter baumannii causing nosocomial infections in a university hospital, Taiwan. Emerging infectious diseases 2002, 8, 827-832.
(25) Corbella, X.; Ariza, J.; Ardanuy, C.; Vuelta, M.; Tubau, F.; Sora, M.; Pujol, M.; Gudiol, F. Efficacy of sulbactam alone and in combination with ampicillin in nosocomial infections caused by multiresistant Acinetobacter baumannii. The Journal of antimicrobial chemotherapy 1998, 42, 793-802.
(26) Garnacho-Montero, J.; Ortiz-Leyba, C.; Jimenez-Jimenez, F. J.; Barrero-Almodovar, A. E.; Garcia-Garmendia, J. L.; Bernabeu-Wittel, I. M.; Gallego-Lara, S. L.; Madrazo-Osuna, J. Treatment of multidrug-resistant Acinetobacter baumannii ventilator-associated pneumonia (VAP) with intravenous colistin: a comparison with imipenem-susceptible VAP. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2003, 36, 1111-1118.
(27) Brauers, J.; Frank, U.; Kresken, M.; Rodloff, A. C.; Seifert, H. Activities of various beta-lactams and beta-lactam/beta-lactamase inhibitor combinations against Acinetobacter baumannii and Acinetobacter DNA group 3 strains. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases 2005, 11, 24-30.
(28) Higgins, P. G.; Wisplinghoff, H.; Stefanik, D.; Seifert, H. In vitro activities of the beta-lactamase inhibitors clavulanic acid, sulbactam, and tazobactam alone or in combination with beta-lactams against epidemiologically characterized multidrug-resistant Acinetobacter baumannii strains. Antimicrobial agents and chemotherapy 2004, 48, 1586-1592.
(29) Levin, A. S. Multiresistant Acinetobacter infections: a role for sulbactam combinations in overcoming an emerging worldwide problem. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases 2002, 8, 144-153.
(30) Levin, A. S.; Levy, C. E.; Manrique, A. E.; Medeiros, E. A.; Costa, S. F. Severe nosocomial infections with imipenem-resistant Acinetobacter baumannii treated with ampicillin/sulbactam. International journal of antimicrobial agents 2003, 21, 58-62.
(31) Obana, Y.; Nishino, T. In-vitro and in-vivo activities of sulbactam and YTR830H against Acinetobacter calcoaceticus. The Journal of antimicrobial chemotherapy 1990, 26, 677-682.
(32) Rodriguez-Hernandez, M. J.; Cuberos, L.; Pichardo, C.; Caballero, F. J.; Moreno, I.; Jimenez-Mejias, M. E.; Garcia-Curiel, A.; Pachon, J. Sulbactam efficacy in experimental models caused by susceptible and intermediate Acinetobacter baumannii strains. The Journal of antimicrobial chemotherapy 2001, 47, 479-482.
(33) Klose, J. Protein mapping by combined isoelectric focusing and electrophoresis of mouse tissues. A novel approach to testing for induced point mutations in mammals. Humangenetik 1975, 26, 231-243.
(34) O'Farrell, P. H. High resolution two-dimensional electrophoresis of proteins. The Journal of biological chemistry 1975, 250, 4007-4021.
(35) Vashist, J.; Tiwari, V.; Kapil, A.; Rajeswari, M. R. Quantitative profiling and identification of outer membrane proteins of beta-lactam resistant strain of Acinetobacter baumannii. Journal of proteome research 2010, 9, 1121-1128.
(36) Reales-Calderon, J. A.; Sylvester, M.; Strijbis, K.; Jensen, O. N.; Nombela, C.; Molero, G.; Gil, C. Candida albicans induces pro-inflammatory and anti-apoptotic signals in macrophages as revealed by quantitative proteomics and phosphoproteomics. Journal of proteomics 2013, 91, 106-135.
(37) Huang, H. L.; Hsing, H. W.; Lai, T. C.; Chen, Y. W.; Lee, T. R.; Chan, H. T.; Lyu, P. C.; Wu, C. L.; Lu, Y. C.; Lin, S. T.; Lin, C. W.; Lai, C. H.; Chang, H. T.; Chou, H. C.; Chan, H. L. Trypsin-induced proteome alteration during cell subculture in mammalian cells. Journal of biomedical science 2010, 17, 36.
(38) Lai, T. C.; Chou, H. C.; Chen, Y. W.; Lee, T. R.; Chan, H. T.; Shen, H. H.; Lee, W. T.; Lin, S. T.; Lu, Y. C.; Wu, C. L.; Chan, H. L. Secretomic and proteomic analysis of potential breast cancer markers by two-dimensional differential gel electrophoresis. Journal of proteome research 2010, 9, 1302-1322.
(39) Chan, H. L.; Gharbi, S.; Gaffney, P. R.; Cramer, R.; Waterfield, M. D.; Timms, J. F. Proteomic analysis of redox- and ErbB2-dependent changes in mammary luminal epithelial cells using cysteine- and lysine-labelling two-dimensional difference gel electrophoresis. Proteomics 2005, 5, 2908-2926.
(40) Chen, Y. W.; Chou, H. C.; Lyu, P. C.; Yin, H. S.; Huang, F. L.; Chang, W. S.; Fan, C. Y.; Tu, I. F.; Lai, T. C.; Lin, S. T.; Lu, Y. C.; Wu, C. L.; Huang, S. H.; Chan, H. L. Mitochondrial proteomics analysis of tumorigenic and metastatic breast cancer markers. Functional & integrative genomics 2011, 11, 225-239.
(41) Chou, H. C.; Chen, Y. W.; Lee, T. R.; Wu, F. S.; Chan, H. T.; Lyu, P. C.; Timms, J. F.; Chan, H. L. Proteomics study of oxidative stress and Src kinase inhibition in H9C2 cardiomyocytes: a cell model of heart ischemia-reperfusion injury and treatment. Free radical biology & medicine 2010, 49, 96-108.
(42) Fukuda, M.; Islam, N.; Woo, S. H.; Yamagishi, A.; Takaoka, M.; Hirano, H. Assessing matrix assisted laser desorption/ ionization-time of flight-mass spectrometry as a means of rapid embryo protein identification in rice. Electrophoresis 2003, 24, 1319-1329.
(43) Karas, M.; Bachmann, D.; Hillenkamp, F. INFLUENCE OF THE WAVELENGTH IN HIGH-IRRADIANCE ULTRAVIOLET-LASER DESORPTION MASS-SPECTROMETRY OF ORGANIC-MOLECULES. Analytical Chemistry 1985, 57, 2935-2939.
(44) Magnet, S.; Courvalin, P.; Lambert, T. Resistance-nodulation-cell division-type efflux pump involved in aminoglycoside resistance in Acinetobacter baumannii strain BM4454. Antimicrobial agents and chemotherapy 2001, 45, 3375-3380.
(45) Wimberly, B. T.; Brodersen, D. E.; Clemons, W. M., Jr.; Morgan-Warren, R. J.; Carter, A. P.; Vonrhein, C.; Hartsch, T.; Ramakrishnan, V. Structure of the 30S ribosomal subunit. Nature 2000, 407, 327-339.
(46) Schmeing, T. M.; Huang, K. S.; Strobel, S. A.; Steitz, T. A. An induced-fit mechanism to promote peptide bond formation and exclude hydrolysis of peptidyl-tRNA. Nature 2005, 438, 520-524.
(47) Stoffler, G.; Hasenbank, R.; Bodley, J. W.; Highland, J. H. Letter: Inhibition of protein L7-L12 binding to 50 S ribosomal cores by antibodies specific for proteins L6, L10 and L18. Journal of molecular biology 1974, 86, 171-174.
(48) Pettersson, I.; Kurland, C. G. Ribosomal protein L7/L12 is required for optimal translation. Proceedings of the National Academy of Sciences of the United States of America 1980, 77, 4007-4010.
(49) Mailloux, R. J.; Lemire, J.; Appanna, V. D. Metabolic networks to combat oxidative stress in Pseudomonas fluorescens. Antonie van Leeuwenhoek 2011, 99, 433-442.
(50) Hartl, F. U. Molecular chaperones in cellular protein folding. Nature 1996, 381, 571-579.
(51) Morimoto, R. I.; Tissières, A.; Georgopoulos, C.: The Biology of heat shock proteins and molecular chaperones; Cold Spring Harbor Laboratory Press: Plainview , N.Y., 1994.
(52) Fenton, W. A.; Horwich, A. L. GroEL-mediated protein folding. Protein science : a publication of the Protein Society 1997, 6, 743-760.
(53) Gomes, S. L.; Simão, R. C. G.: Stress response: heat. In In Encyclopedia of Microbiology; Schaechter, M., Ed.; Elsevier Academic Press: Oxford, 2009; pp 464-474.
(54) Yura, T.; Kanemori, M.; Morita, M. T.: The Heat Shock Response: Regulation and Function. In Bacterial Stress Response; Storz, G., Hengge, R., Eds.; ASM Press: Washington DC, 2000; pp 75-90.
(55) Champomier-Verges, M. C.; Maguin, E.; Mistou, M. Y.; Anglade, P.; Chich, J. F. Lactic acid bacteria and proteomics: current knowledge and perspectives. Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 2002, 771, 329-342.
(56) Frees, D.; Ingmer, H. ClpP participates in the degradation of misfolded protein in Lactococcus lactis. Molecular microbiology 1999, 31, 79-87.
(57) Hartke, A.; Frere, J.; Boutibonnes, P.; Auffray, Y. Differential induction of the chaperonin GroEL and the Co-chaperonin GroES by heat, acid, and UV-irradiation in Lactococcus lactis subsp. lactis. Current microbiology 1997, 34, 23-26.
(58) Jayaraman, G. C.; Penders, J. E.; Burne, R. A. Transcriptional analysis of the Streptococcus mutans hrcA, grpE and dnaK genes and regulation of expression in response to heat shock and environmental acidification. Molecular microbiology 1997, 25, 329-341.
(59) Lemos, J. A.; Chen, Y. Y.; Burne, R. A. Genetic and physiologic analysis of the groE operon and role of the HrcA repressor in stress gene regulation and acid tolerance in Streptococcus mutans. Journal of bacteriology 2001, 183, 6074-6084.
(60) Cardoso, K.; Gandra, R. F.; Wisniewski, E. S.; Osaku, C. A.; Kadowaki, M. K.; Felipach-Neto, V.; Haus, L. F.; Simao Rde, C. DnaK and GroEL are induced in response to antibiotic and heat shock in Acinetobacter baumannii. Journal of medical microbiology 2010, 59, 1061-1068.