ライフサイエンスコーパス: Gram-negative bacteria

1 e potentially useful biological functions in Gram negative bacteria.

2 s on the cell wall of both gram positive and gram negative bacteria.

3 overy and development of antibiotics against Gram-negative bacteria.

4 isms of action of Ctn and Ctn(15-34) against Gram-negative bacteria.

5 lated inhibitor of DsbB enzymes from several Gram-negative bacteria.

6 similar to the HJ migration helicase RuvB in Gram-negative bacteria.

7 e bacterial cell surface was demonstrated in Gram-negative bacteria.

8 against multidrug-resistant tuberculosis and Gram-negative bacteria.

9 ride (LPS) constituting the outer leaflet of Gram-negative bacteria.

10 for developing countermeasures in pathogenic Gram-negative bacteria.

11 ed from work with Escherichia coli and other Gram-negative bacteria.

12 essential outer membrane glycolipids in most gram-negative bacteria.

13 nserved cell-cell communication mechanism in Gram-negative bacteria.

14 ycobacteria, and anaerobic Gram-positive and Gram-negative bacteria.

15 change of acyl-homoserine lactones (AHLs) by Gram-negative bacteria.

16 (LPS), the major outer-membrane component of Gram-negative bacteria.

17 ne" antibiotic against extensively-resistant Gram-negative bacteria.

18 sity and the ratio between Gram-positive and Gram-negative bacteria.

19 otics with improved permeation properties in Gram-negative bacteria.

20 r infections caused by highly drug-resistant Gram-negative bacteria.

21 difference in antibacterial potency towards Gram-negative bacteria.

22 odulation cell division (RND) exporters from Gram-negative bacteria.

23 new drug to treat lung infections caused by Gram-negative bacteria.

24 -acyl homoserine lactones (AHLs) in numerous Gram-negative bacteria.

25 istep biosynthetic pathway conserved in most Gram-negative bacteria.

26 tion in the fight against pan-drug-resistant Gram-negative bacteria.

27 e II, III, and IV secretion systems found in Gram-negative bacteria.

28 y activity against several gram-positive and gram-negative bacteria.

29 irectly down-regulating AraC/XylS members in Gram-negative bacteria.

30 antimicrobial activities, especially against Gram-negative bacteria.

31 ivity against bacterial infections caused by Gram-negative bacteria.

32 t commensal and pathogenic Gram-positive and Gram-negative bacteria.

33 rial property against both Gram-positive and Gram-negative bacteria.

34 arker, plays a key role in host responses to gram-negative bacteria.

35 sphatidylethanolamine (lyso-PE) recycling in Gram-negative bacteria.

36 ilic antibiotics cross the outer membrane of Gram-negative bacteria.

37 ith selective antimicrobial activity against Gram-negative bacteria.

38 n the spread of antibiotic resistance across Gram-negative bacteria.

39 es and extracellular exopolysaccharides from Gram-negative bacteria.

40 l)-N-acetylglucosamine deacetylase (LpxC) in Gram-negative bacteria.

41 analogous pathway has yet to be described in Gram-negative bacteria.

42 sensing caspase-11 and NLRP3 inflammasome by Gram-negative bacteria.

43 and pili proteins within clinically relevant Gram-negative bacteria.

44 esponse to cell wall damage, particularly in Gram-negative bacteria.

45 across the asymmetric outer membrane (OM) of Gram-negative bacteria.

46 bacterial activity against Gram-positive and Gram-negative bacteria.

47 her MDR pathogens, such as malaria, HIV, and Gram-negative bacteria.

48 rial surfaces against both Gram-positive and Gram-negative bacteria.

49 is an eight-carbon sugar mostly confined to Gram-negative bacteria.

50 atterns of lipid A variants from a number of Gram-negative bacteria.

51 ralizing activity by interacting with LPS of Gram-negative bacteria.

52 ajor contribution to multidrug resistance in Gram-negative bacteria.

53 upies the space between the two membranes of Gram-negative bacteria.

54 n the outer leaflet of the outer membrane of Gram-negative bacteria.

55 to combat multidrug-resistant infections by Gram-negative bacteria.

56 ccharides that fulfill crucial functions for Gram-negative bacteria.

57 r, there are currently few studies examining Gram-negative bacteria.

58 Gram-positive phylum Firmicutes and in some Gram-negative bacteria.

59 d with several other intact Gram-positive or Gram-negative bacteria.

60 purposing candidate to treat infections with Gram-negative bacteria.

61 protein found in the outer membranes of most Gram-negative bacteria.

62 m also controls virulence in many pathogenic Gram-negative bacteria.

63 nner core in guiding LL-37 to the surface of Gram-negative bacteria.

64 yrase with a strong activity against various Gram-negative bacteria.

65 protein is secreted to the outer surface of Gram-negative bacteria.

66 bial activity against both gram-positive and gram-negative bacteria.

67 mediate cellular entry of small molecules in Gram-negative bacteria.

68 xes, which assemble in the outer membrane of Gram-negative bacteria.

69 is, we propose to redefine Planctomycetes as Gram-negative bacteria.

70 phospholipid synthesis found in free living Gram-negative bacteria.

71 otein in the extracellular matrix of enteric Gram-negative bacteria.

72 tic cell-cell interactions between competing Gram-negative bacteria.

73 t clinical needs in treating infections with Gram-negative bacteria.

74 are also relevant for other T3SS-containing Gram-negative bacteria.

75 domains are widespread in toxins that target Gram-negative bacteria.

76 eta-barrel outer membrane proteins (OMPs) in Gram-negative bacteria.

77 rel proteins into the outer membrane (OM) of Gram-negative bacteria.

78 sidues that occurs in most Gram-positive and Gram-negative bacteria.

79 anders are multifaceted infections caused by gram-negative bacteria.

80 mbrane has long defined the cell envelope of Gram-negative bacteria.

81 e role of Type Vd secreted phospholipases in Gram-negative bacteria.

82 with the virulence of medically significant Gram-negative bacteria.

83 fections caused by multidrug-resistant (MDR) Gram-negative bacteria.

84 iaminopimelic-type peptidoglycans present in Gram-negative bacteria.

85 communication within and between species of Gram-negative bacteria.

86 LPS biosynthesis, transport, and assembly in Gram-negative bacteria.

87 idal activity against both Gram-positive and Gram-negative bacteria.

88 ity of specific Gram-positive antibiotics to Gram-negative bacteria.

89 and TonB-dependent transporters (TBDT) from Gram-negative bacteria.

90 both bacterial lipopolysaccharide (LPS) and gram-negative bacteria.

91 il microbial biomass, primarily by fungi and Gram-negative bacteria.

92 The cell envelope of gram-negative bacteria, a structure comprising an outer

93 secondary immunization with MenC or another Gram-negative bacteria, Acinetobacter baumannii, did not

94 ated molecular patterns in gram-positive and gram-negative bacteria activate IL-1beta release from im

95 Lipopolysaccharide (LPS) derived from Gram-negative bacteria activates plasma membrane signali

96 um chemotaxis towards live gram positive and gram negative bacteria and demonstrate high sensitivity

97 Conjugate significantly inhibited gram negative bacteria and the antibacterial activity al

98 urpose, we chose the pilus protein FimG from Gram-negative bacteria and a disulfide-bonded variant of

99 nzyme of the lipid A biosynthetic pathway in Gram-negative bacteria and a validated novel antibiotic

100 le to rapidly traverse the outer membrane of Gram-negative bacteria and accumulate inside these cells

101 BamA orthologues are found in all Gram-negative bacteria and appear to function in a speci

102 acteria that are obligate predators of other Gram-negative bacteria and are considered potential alte

103 s (OMPs) are found in the outer membranes of Gram-negative bacteria and are essential for nutrient im

104 he periplasmic side of the inner membrane of Gram-negative bacteria and are then extracted by the Lpt

105 Compounds were tested against a panel of Gram-negative bacteria and counter-screened for in vitro

106 biofilm resistance to both Gram-positive and Gram-negative bacteria and fungi: it remains almost "zer

107 ed protein H-NS is a key global regulator in Gram-negative bacteria and is believed to be a crucial p

108 a six-component system that is widespread in Gram-negative bacteria and is thought to mediate retrogr

109 lass of molecules found in Gram-positive and Gram-negative bacteria and most archaea(1-5).

110 Many proteins of the outer membrane of Gram-negative bacteria and of the outer envelope of the

111 The hallmark of gram-negative bacteria and organelles such as mitochondr

112 line for pilus production at the surface of Gram-negative bacteria and the archetypical protein-poly

113 ericidal protein that limits contact between Gram-negative bacteria and the colonic epithelial surfac

114 eplicated the activity of parent Ctn against Gram-negative bacteria and tumor cells while being signi

115 iens, Viridiplantae, Gram-positive Bacteria, Gram-negative Bacteria and Virus .

116 e widespread in Gram-positive bacteria, some Gram-negative bacteria, and Archaea.

117 io aeruginosavorus are obligate predators of Gram-negative bacteria, and have been proposed to be use

118 ere bacteria, including Legionella and other gram-negative bacteria, and nontuberculous mycobacteria,

119 enable gene exchange between five species of Gram-negative bacteria, and that the identity of the gen

120 g highly effective against Gram-positive and Gram-negative bacteria; and (iii) the concentration of t

121 The most prevalent uropathogenic gram negative bacteria are Escherichia coli, Proteus mir

122 Gram-negative bacteria are common in pneumonia and incre

123 udies have shown that conjugation systems of Gram-negative bacteria are composed of distinct inner an

124 ved that nearly all lipoproteins produced by Gram-negative bacteria are either retained in the inner

125 The OMPs in Gram-negative bacteria are inserted and folded into the

126 Although a number of Gram-negative bacteria are known to catabolize quinate a

127 y outer membrane vesicles (OMVs) produced by Gram-negative bacteria as a vehicle that delivers LPS in

128 functional amyloid fibers assembled by many Gram-negative bacteria as part of an extracellular matri

129 oodstream infection, although an increase in Gram-negative bacteria as the causative agent has been n

130 ling and export of amyloid protein sequences.Gram-negative bacteria assemble biofilms from amyloid fi

131 Gram-negative bacteria balance synthesis of the outer me

132 ies have focused on antibiotic resistance of Gram-negative bacteria before and after periodontal ther

133 f the greatest threats to human health, with gram-negative bacteria being of major concern.

134 s can be delivered to both Gram-positive and Gram-negative bacteria boosting both photoantibacterial

135 ipid A is essential for the survival of most Gram-negative bacteria, but colistin-resistant Acinetoba

136 described and are encoded in the majority of Gram-negative bacteria, but neither is present in Gram-p

137 acellular sensors for both Gram-positive and Gram-negative bacteria, but their role in steady-state h

138 erious infections due to multidrug-resistant Gram-negative bacteria, but their use is threatened by t

139 These results suggest that TriA1 kills Gram-negative bacteria by a mechanism of action using a

140 Mouse and human RELMbeta selectively killed Gram-negative bacteria by forming size-selective pores t

141 Lipopolysaccharide dispersed in the blood by Gram-negative bacteria can be a potent inducer of septic

142 ibodies targeting an epitope conserved among Gram-negative bacteria can protect the host from systemi

143 ssociated with a reduction in acquisition of Gram-negative bacteria carriage in the respiratory tract

144 Bioinformatic screens reveal that these gram-negative bacteria carry genes coding for thiol-disu

145 90 bloodstream isolates of the 4 most common gram-negative bacteria causing bloodstream infections in

146 evalence of MCRPE infection from isolates of Gram-negative bacteria collected at the hospitals from 2

147 membranes representing the inner membrane of Gram-negative bacteria, comprising a mixture of 128 anio

148 The cell surface of most Gram-negative bacteria contains lipopolysaccharide that

149 release (ER) in severe infections caused by gram-negative bacteria could be a matter of concern.

150 ng target for antibiotic development against Gram-negative bacteria due to differences from the human

151 pime-tazobactam when tested against clinical Gram-negative bacteria during clinical studies and routi

152 nder a low light dose (0.6 J cm(-2) ) toward Gram-negative bacteria E. coli, making it a remarkably e

153 h TLR4, as well as through activation by the Gram-negative bacteria E. coli, results in reduced NET p

154 In Gram-negative bacteria, efflux pumps are able to prevent

155 HFM and showed that HFM increases rat fecal Gram-negative bacteria, elevates lipopolysaccharides (LP

156 penetrated through the cell membrane of the Gram-negative bacteria Escherichia coli (pGEM::ureOP) in

157 s and Enterococcus faecalis, and against the Gram-negative bacteria Escherichia coli, Escherichia col

158 isolates had antibacterial activity against Gram negative bacteria (Escherichia coli and Salmonella

159 y that targets a highly conserved protein of Gram-negative bacteria essential for the fitness of V. c

160 anism of inter-cellular competition in which Gram-negative bacteria exchange polymorphic toxins using

161 Gram-negative bacteria express a diverse array of lipopr

162 of any known membrane-embedded insertase in Gram-negative bacteria fold into a prepore before membra

163 , III, IV, and VI), which are widely used by Gram-negative bacteria for pathogenesis.

164 bat multidrug resistant bacteria, especially Gram-negative bacteria for which the situation is partic

165 he OM plays a fundamental role in protecting Gram-negative bacteria from harsh environments and toxic

166 rates native lipids and membrane proteins of gram-negative bacteria from outer membrane vesicles (OMV

167 Gram-negative bacteria from the human gut microbiome enc

168 nt light on the mechanism of CL transport in Gram-negative bacteria from the IM to the OM, which offe

169 Gram-negative bacteria from the Legionella genus are int

170 Mechanisms of drug resistance in gram-negative bacteria (GNB) are numerous; beta-lactamas

171 Predicting antimicrobial resistance in gram-negative bacteria (GNB) could balance the need for

172 tibiotics includes multidrug-resistant (MDR) gram-negative bacteria (GNB), including Pseudomonas aeru

173 Gram-negative bacteria (GNBs) are common pathogens causi

174 will be the effectiveness of EDP on reducing Gram-negative bacteria growth and the opposite trend was

175 is swarming differentiation, whereas EF-P in Gram-negative bacteria has a more global housekeeping ro

176 ncreasing dissemination of carbapenemases in Gram-negative bacteria has threatened the clinical usefu

177 espread antibiotic resistance, especially of Gram-negative bacteria, has become a severe concern for

178 these is the number of efficient approaches Gram-negative bacteria have developed to avoid intracell

179 Multidrug-resistant (MDR) gram-negative bacteria have increased the prevalence of

180 In enteric Gram-negative bacteria, Hfq is required for sRNA regulat

181 e active against Gram positive bacteria than Gram negative bacteria; however zerumbone showed highest

182 id development of resistance particularly in Gram-negative bacteria, illustrates the urgent need for

183 ed to invade, reseal, kill, and digest other gram-negative bacteria in soils and water environments.

184 AMP responses against both Gram-positive and Gram-negative bacteria in T. molitor.

185 e (AHL) quorum-sensing molecules produced by gram-negative bacteria in the gut can influence the home

186 Among patients not colonized with Gram-negative bacteria in the respiratory tract at admis

187 onjugate, 42, has excellent activity against Gram-negative bacteria including carbapenemase and carba

188 he biosensor construct was tested in several Gram-negative bacteria including Pseudomonas, Shewanella

189 it is widespread in more than 25 species of Gram-negative bacteria, including enterohemorrhagic E. c

190 at is critical for the pathogenicity of many Gram-negative bacteria, including purveyors of plague, t

191 In many Gram-negative bacteria, including Rhodobacter capsulatus

192 These Gram-negative bacteria, including the species Vibrio vul

193 The zauPzapA operon is present in diverse Gram-negative bacteria, indicating a common mechanism fo

194 an effective permeability barrier that makes Gram-negative bacteria inherently resistant to many anti

195 machines used for injection of proteins from Gram-negative bacteria into eukaryotic cells.

196 genesis of outer-membrane proteins (OMPs) in gram-negative bacteria involves delivery by periplasmic

197 l peptides (AMPs) with the inner membrane of Gram-negative bacteria is a key determinant of their abi

198 The outer membrane (OM) of Gram-negative bacteria is a permeability barrier and an

199 The outer membrane (OM) of Gram-negative bacteria is a unique asymmetric lipid bila

200 that the surface exposure of lipoproteins in Gram-negative bacteria is a widespread phenomenon and di

201 The outer membrane (OM) of gram-negative bacteria is an unusual asymmetric bilayer

202 ent of lipopolysaccharides on the surface of gram-negative bacteria is both a virulence factor and a

203 eactivity to antigens from Gram-positive and Gram-negative bacteria is common in patients suffering f

204 The Cu tolerance system in Gram-negative bacteria is composed minimally of a Cu sen

205 t protective layer of both Gram-positive and Gram-negative bacteria is composed of bacterial capsular

206 The outer membrane (OM) of Gram-negative bacteria is composed of lipopolysaccharide

207 The outer membrane of gram-negative bacteria is composed of phospholipids in t

208 of the endotoxic lipopolysaccharide layer of Gram-negative bacteria is comprised of a diglucosamine b

209 olysaccharide (LPS) in the outer membrane of Gram-negative bacteria is critical for the assembly of t

210 ck of activity of auranofin observed against Gram-negative bacteria is due to the permeability barrie

211 that dictate small-molecule accumulation in Gram-negative bacteria is largely based on retrospective

212 The first barrier for targeting gram-negative bacteria is layer of a Lipopolysaccharides

213 g of the biogenesis of the outer membrane of Gram-negative bacteria is of critical importance due to

214 Antimicrobial resistance in pathogenic gram-negative bacteria is one of the most pressing chall

215 he mechanism of action of promysalin against Gram-negative bacteria is still not clarified, even if a

216 One attractive target in Gram-negative bacteria is the unique asymmetric outer me

217 the major component of the outer membrane of Gram-negative bacteria, is a strong trigger of these pat

218 Pseudomonas aeruginosa was the only Gram negative bacteria isolated from corneal ulcer cases

219 Our results indicate that Gram-negative bacteria isolated from the equine uterus a

220 In Gram-negative bacteria, lipid asymmetry is critical for

221 In Gram-negative bacteria, lipid modification of proteins i

222 and outer membranes of the cell envelope in Gram-negative bacteria, maintains cell shape and endows

223 es for the prevention of multidrug-resistant gram-negative bacteria (MDR-GNB) in adult intensive care

224 All Gram-negative bacteria, mitochondria and chloroplasts ha

225 multitude of essential cellular functions in Gram-negative bacteria, mitochondria and chloroplasts.

226 activation and thus may be a means by which Gram-negative bacteria modulate host immunity.

227 The T6SS is widespread among Gram-negative bacteria, mostly within the Proteobacteriu

228 In this study, using Gram-negative bacteria mutated for the riboflavin biosyn

229 n across the cell envelope are widespread in Gram-negative bacteria, NBs are found exclusively in gam

230 ation within the Bacteroidales, the dominant Gram-negative bacteria of the human intestine.

231 MTPs prepared with 17 antibiotics targeting Gram-negative bacteria on clinical isolates of Klebsiell

232 Among Gram-negative bacteria, only methylene blue with E. coli

233 Activation of TLR4 by Gram-negative bacteria or lipopolysaccharide accelerates

234 In Gram-negative bacteria, outer membrane phospholipase A (

235 In Gram-negative bacteria, outer membrane transporters impo

236 Gram-negative bacteria possess a characteristic outer me

237 Gram-negative bacteria possess specialised biogenesis ma

238 large group of capsular polysaccharides from Gram-negative bacteria, produced by ATP-binding cassette

239 rains 0.3-8 mug/mL) than for the majority of Gram negative bacteria (Pseudomonas aeruginosa, 16-32 mu

240 occus aureus and Streptococcus pyogenes) and gram-negative bacteria (Pseudomonas aeruginosa and Esche

241 togenes, Geobacillus stearothermophilus) and gram-negative bacteria (Pseudomonas aeruginosa, Pseudomo

242 lex (Bcc) are a group of multidrug-resistant gram-negative bacteria rarely reported in patients witho

243 During infection, Gram-negative bacteria remodel their OM to promote survi

244 Gram-negative bacteria remodel their surfaces to interac

245 ctivity against a panel of Gram-positive and Gram-negative bacteria revealed structure-activity relat

246 ysates of DNA extracted from the pathogenic, Gram-negative bacteria Salmonella enterica serovar Monte

247 Gram-negative bacteria secrete proteins using a type III

248 ride (LPS), which is a membrane component of gram-negative bacteria, secrete more EVs than cholangioc

249 represent a major mechanism of resistance in Gram-negative bacteria showing multi-drug or extensively

250 In Gram-negative bacteria, some of these pumps form multi-p

251 del for studying how antimicrobial-resistant Gram-negative bacteria spread globally.

252 light that, although BAM is conserved across Gram-negative bacteria, structural and functional differ

253 ly associated with increased colonization of gram-negative bacteria such as Burkholderia spp. and mem

254 Gram-negative bacteria such as Escherichia coli are prot

255 Secreted pore-forming toxins of pathogenic Gram-negative bacteria such as Escherichia coli hemolysi

256 c children, nasopharyngeal colonization with Gram-negative bacteria such as Haemophilus influenzae an

257 llus subtilis and Staphylococcus aureus, and gram-negative bacteria, such as Escherichia coli and Pse

258 Images of gram-positive and gram-negative bacteria taken with this technique show ex

259 in the Class Alphaproteobacteria, a group of Gram negative bacteria that are highly heterogeneous in

260 Most Gram-negative bacteria that activate caspase-11, however

261 Lipopolysaccharide (LPS) is the component of Gram-negative bacteria that activates Toll-like receptor

262 Lysobacter species are Gram-negative bacteria that are emerging as new sources

263 ly identified cell wall recycling pathway in Gram-negative bacteria that bypasses the general de novo

264 ucella species are facultative intracellular gram-negative bacteria that cause brucellosis, a common

265 Brucella spp. are facultative intracellular Gram-negative bacteria that cause the zoonotic disease b

266 genome, an atypical genetic arrangement for Gram-negative bacteria that elaborate a capsule dependen

267 The Enterobacteriaceae are a family of Gram-negative bacteria that include commensal organisms

268 imeric channels across the outer membrane of Gram-negative bacteria that mediate the import or export

269 ffords RhB-Glc-Ent, it can selectively label Gram-negative bacteria that utilize Ent, including some

270 In many Gram-negative bacteria, the peptidoglycan synthase PBP1A

271 In many Gram-negative bacteria, the type III secretion system tr

272 Proteins (PGRPs) kill both Gram-positive and Gram-negative bacteria through simultaneous induction of

273 complexes constitute a primary mechanism for Gram-negative bacteria to expel toxic molecules for surv

274 SS) is a macromolecular machine used by many Gram-negative bacteria to inject effectors/toxins into e

275 Outer membrane proteins are essential for Gram-negative bacteria to rapidly adapt to changes in th

276 and utilization of enterobactin permits many Gram-negative bacteria to thrive in environments where l

277 acter baumannii is one of the most difficult Gram-negative bacteria to treat and eradicate.

278 an discriminate between viable and nonviable Gram-negative bacteria to tune the immune response, ther

279 In response to intracellular signals in Gram--negative bacteria, translational riboswitches--com

280 ve infections caused by carbapenem-resistant gram-negative bacteria treated with colistin.

281 hia coli as representative Gram-positive and Gram-negative bacteria under dark and light conditions.

282 -dependent growth inhibition (CDI), in which Gram-negative bacteria use CdiB/CdiA two-partner secreti

283 Many pathogenic Gram-negative bacteria use the type III secretion system

284 Many Gram-negative bacteria use type 2 secretion systems (T2S

285 Gram-negative bacteria use type IV secretion systems (T4

286 omysalin is active against Gram-positive and Gram-negative bacteria using a microdilution assay.

287 fferential immune responses to dead and live Gram-negative bacteria using the single peptidoglycan re

288 Gram-negative bacteria utilize TonB-dependent outer memb

289 cytosolic presence of lipopolysaccharide of Gram-negative bacteria via inflammatory caspases such as

290 studies, we found that the activity against Gram-negative bacteria was largely associated with the N

291 Colonization by resistant gram-negative bacteria was significantly associated with

292 le for detecting lipopolysaccharide (LPS) of Gram-negative bacteria, was immobilized on both a large

293 eight different species of Gram-positive and Gram-negative bacteria, we demonstrate that this "chemic

294 We report that selective gut symbiotic gram-negative bacteria were able to disseminate systemic

295 After two hours, Gram-positive and Gram-negative bacteria were reduced to below the detecti

296 were sensitive to vancomycin (27/27, 100%); gram-negative bacteria were sensitive to amikacin (5/5,

297 ted excellent sensitivity to trace levels of Gram-negative bacteria, while remaining insensitive to b

298 C is a two-subunit enzyme in a collection of Gram-negative bacteria, with the alpha subunit containin

299 sceptibility profiles of clinically relevant Gram-negative bacteria within two hours of antibiotic in

300 is markedly induced by avirulent strains of Gram-negative bacteria, Yersinia and Klebsiella, and les