Multidrug-Resistant Enterococci in Animal Meat and Faeces and Co-Transfer of Resistance from an <Emphasis Type="Italic">Enterococcus durans</Emphasis> to a Human <Emphasis Type="Italic">Enterococcus faecium</Emphasis>

Forty-eight isolates resistant to at least two antibiotics were selected from 53 antibiotic-resistant enterococci from chicken and pig meat and faeces and analysed for specific resistance determinants. Of the 48 multidrug-resistant (MDR) strains, 31 were resistant to two antibiotics (29 to erythromycin and tetracycline, 1 to erythromycin and vancomycin, 1 to vancomycin and tetracycline), 14 to three (erythromycin, tetracycline and vancomycin or ampicillin) and 3 to four (erythromycin, vancomycin, ampicillin and gentamicin). erm(B), tet(M), vanA and aac (6′)-Ie aph (2′′)-Ia were the antibiotic resistance genes most frequently detected. All 48 MDR enterococci were susceptible to linezolid and daptomycin. Enterococcus faecalis (16), Enterococcus faecium (8), Enterococcus mundtii (2) and Enterococcus gallinarum (1) were identified in meat, and E. faecium (13) and Enterococcus durans (13) in faeces. Clonal spread was not detected, suggesting a large role of gene transfer in the dissemination of antibiotic resistance. Conjugative transfer of resistance genes was more successful when donors were enterococcal strains isolated from faeces; co-transfer of vanA and erm(B) to a human E. faecium occurred from both E. faecium and E. durans pig faecal strains. These data show that multidrug resistance can be found in food and animal species other than E. faecium and E. faecalis, and that these species can efficiently transfer antibiotic resistance to human strains in inter-specific matings. In particular, the occurrence of MDR E. durans in the animal reservoir could have a role in the emergence of human enterococcal infections difficult to eradicate with antibiotics.     

Multiple antibiotic resistances of <Emphasis Type="Italic">Enterococcus</Emphasis> isolates from raw or sand-filtered sewage

Fifty antibiotic-resistant Enterococcus strains were isolated from raw sewage of a wastewater treatment plant and from the same sewage after trickling through a 25-cm sand column, which retained >99% of the initial population. All 50 Enterococcus isolates were resistant against triple sulfa and trimethoprim/sulfamethoxazole and none were resistant against vancomycin. Most of the isolates from raw sewage were resistant to more antibiotics than the isolates from sand column effluent. One Enterococcus isolate from raw sewage (no. 61) and one Enterococcus isolate from sand column effluent (no. 95) had ten antibiotic resistances each. Isolate no. 95 maintained its resistances in the absence of antibiotics during the whole study. It was compared with isolate no. 70, which was one of the isolates, being resistant only against the two sulfonamides. Phenotypically and biochemically, the two organisms were strains of Enterococcus faecalis. Sequence analysis of partical 16S rDNA allowed alignment of isolate no. 95 as a strain of Enterococcus faecium and of isolate no. 70 as a strain of E. faecalis. E. faecium strain no. 95 carried at least six different plasmids, whereas for E. faecalis strain no. 70, no discrete plasmid band was seen on the gels.     

Diarrheagenic <Emphasis Type="Italic">Escherichia coli</Emphasis> Strains Recovered from Urban Pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>) in Brazil and Their Antimicrobial Susceptibility Patterns

Urban pigeons (Columba livia) come into close contact with humans and animals, and may contribute to the spread of infectious agents. These may include human pathogens such as diarrheagenic Escherichia coli strains, which are able to survive in pigeon feces, thus creating potential for human exposure and infection. Our objectives were to determine the occurrence of diarrheagenic E. coli strains in fresh feces from urban pigeons and their drug susceptibility patterns. E. coli strains were isolated from 100 fresh feces samples and presumptive phenotypic species identification was carried out, confirmed by amplification of specific 16S ribosomal RNA encoding DNA. Multiplex PCR was performed to characterize pathogenic strains. Drug susceptibility patterns were determined by the agar dilution method. Enteroinvasive E. coli, Shiga toxin-producing E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli were detected at an overall rate of 12.1%. Among the isolated E. coli strains, 62.1% were susceptible to all tested drugs, whereas 37.9% were resistant to at least one of the antimicrobials tested. Amikacin was the less effective drug (36.8% resistance), followed by ampicillin (7.8%). No resistance was detected to gentamicin, ceftriaxone, and ceftazidime and almost all the isolates were susceptible to ampicillin-sulbactam (98.4%), levofloxacin (97.8%), and trimethoprim-sulfametoxazole (96.1%). Since these pigeons may harbor multidrug-resistant pathogens, their presence in an urban environment could be an important component of infection spread, with impact on public health.     

Prevalence and antibiotic resistance of <Emphasis Type="Italic">Escherichia coli</Emphasis> in tropical seafood

Summary The occurrence and antibiotic resistance of Escherichia coli in tropical seafood was studied. A 3-tube MPN method was used for determining the level of faecal contamination of fresh and processed seafood. Of the 188 samples tested which included finfish, shellfish, water and ice, 155 were positive for the presence of faecal coliforms following incubation at 44.5 °C. However, E. coli was isolated from only 47% of the samples positive for faecal coliforms. The antibiotic resistance of 116 strains isolated from seafood was tested using 14 different antibiotics including ampicillin, cephalothin, chloramphenicol, ciprofloxacin, gentamycin, nalidixic acid, streptomycin and vancomycin. Seven strains were resistant to more than five antibiotics of which one was resistant to eight antibiotics. The multiple drug resistant strains harboured plasmids of varying sizes. Antibiotic susceptibility studies revealed that seafood from India contains multiple antibiotic resistant strains of E. coli which may serve as a reservoir for antibiotic resistance genes in the aquatic environment. All the strains used in this study did not harbour any virulence genes commonly associated with pathogenic E. coli, when tested by polymerase chain reaction (PCR).     

Evidence of <Emphasis Type="Italic">Anaplasma phagocytophilum</Emphasis> and <Emphasis Type="Italic">Rickettsia helvetica</Emphasis> infection in free-ranging ungulates in central Slovakia

The purpose of this study was to investigate the role of wild animals for Anaplasma phagocytophilum, other ehrlichiae/anaplasmae, Rickettsia helvetica and other rickettsiae and whether different genetic variants of A. phagocytophilum in central Slovakia exist. A total of 109 spleen samples from 49 red deer (Cervus elaphus), 30 roe deer (Capreolus capreolus), 28 wild boar (Sus scrofa) and two mouflon (Ovis musimon) were collected from June 2005 to December 2006. Polymerase chain reaction (PCR) amplification of the16S rRNA gene was used for detection of ehrlichiae/anaplasmae. A nested PCR targeting part (392 bp) of groESL gene was applied for the specific detection of A. phagocytophilum. Fragments of the gltA and ompA genes (381 bp and 632 bp, respectively) were amplified to detect rickettsiae, followed by sequencing. A. phagocytophilum and R. helvetica were detected in wild animals. The prevalence of A. phagocytophilum was 50.0 ± 18.2% in roe deer and 53.1 ± 14.1% in red deer. None of the 28 wild boar was PCR positive for ehrlichiae/anaplasmae. A. phagocytophilum was detected in one mouflon. R. helvetica was found in one roe deer. Our study suggests a role of cervids as a natural reservoir of A. phagocytophilum in Slovakia. However, the role of cervids and wild boars in the circulation of R. helvetica remains unknown. The analysis of sequence variation in the msp4 coding region of A. phagocytophilum showed the presence of different variants previously described in ruminants.     

Epidemiological investigation of <Emphasis Type="Italic">eaeA</Emphasis>-positive <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Escherichia albertii</Emphasis> strains isolated from healthy wild birds

Escherichia coli has commonly been associated with diarrheal illness in humans and animals. Recently, E. albertii has been reported to be a potential pathogen of humans and animals and to be carried by wild birds. In the present study, the prevalence and genetic characteristics of intimin-producing E. coli and E. albertii strains were evaluated in wild birds in Korea. Thirty one of 790 Enterobacteriaceae strains from healthy wild birds were positive for the intimin gene (eaeA) and twenty two of the 31 strains were identified as atypical enteropathogenic E. coli (aEPEC) that did not possess both EAF and bfpA genes. A total of nine lactose non-fermenting coliform bacterial strains were identified as E. albertii by PCR and sequence analysis of housekeeping genes. A total of 28 (90.3%) eaeA-positive strains were isolated from waterfowl. Fifteen aEPEC (68.2%) and two E. albertii (22.2%) strains had a β-intimin subtype and 14 aEPEC strains harboring β-intimin belonged to phylogenetic group B2. AU eaeA-positive E. albertii and 3 aEPEC strains possessed the cytolethal distending toxin gene (cdtB). The eaeA-positive E. coli and E. albertii strains isolated from healthy wild birds need to be recognized as a potential pathogroup that may pose a potential threat to human and animal health. These findings indicate that eaeA-positive E. coli as well as E. albertii can be carried by wild birds, posing a potential threat to human and animal health.     

In vitro selection of resistance in <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Klebsiella</Emphasis> spp. at <Emphasis Type="Italic">in vivo</Emphasis> fluoroquinolone concentrations

Background  

Fluoroquinolones are potent antimicrobial agents used for the treatment of a wide variety of community- and nosocomial- infections. However, resistance to fluoroquinolones in Enterobacteriaceae is increasingly reported. Studies assessing the ability of fluoroquinolones to select for resistance have often used antimicrobial concentrations quite different from those actually acquired at the site of infection. The present study compared the ability to select for resistance of levofloxacin, ciprofloxacin and prulifloxacin at concentrations observed in vivo in twenty strains of Escherichia coli and Klebsiella spp. isolated from patients with respiratory and urinary infections. The frequencies of spontaneous single-step mutations at plasma peak and trough antibiotic concentrations were calculated. Multi-step selection of resistance was evaluated by performing 10 serial cultures on agar plates containing a linear gradient from trough to peak antimicrobial concentrations, followed by 10 subcultures on antibiotic-free agar. E. coli resistant strains selected after multi-step selection were characterized for DNA mutations by sequencing gyrA, gyrB, parC and parE genes.     

Comparative characterization of endo-polygalacturonase (<Emphasis Type="Italic">Pgu1</Emphasis>) from <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> and <Emphasis Type="Italic">Saccharomyces paradoxus</Emphasis> under winemaking conditions

A peptide antibiotic, gramicidin A, was covalently bound to cystamine self-assembled monolayers on gold surfaces. Each step of the surface functionalization was characterized by polarization modulation infrared reflection absorption spectroscopy and X-ray photoelectron spectroscopy. The antimicrobial activity of the anchored gramicidin was tested against three Gram-positive bacteria (Listeria ivanovii, Enterococcus faecalis, and Staphylococcus aureus), the Gram-negative bacterium Escherichia coli and the yeast Candida albicans. The results revealed that the adsorbed gramicidin reduced, from 60% for E. coli to 90% for C. albicans, the number of culturable microorganisms attached to the surface. The activity was proven to be persistent overtime, up to 6 months after the first use. The bacteria attached to the functionalized surfaces were permeabilized as shown by confocal microscopy. Taken together, these results indicate a bacteriostatic mode of action of the immobilized peptide. Finally, using green fluorescent protein-expressing bacteria, it was shown that the development of a bacterial biofilm was delayed on peptide-grafted surfaces for at least 24 h.     

Transfer of the chromosomally encoded tetracycline resistance gene <Emphasis Type="Italic">tet</Emphasis>(M) from marine bacteria to <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Enterococcus faecalis</Emphasis>

The transferability of the tetracycline (TC) resistance gene tet(M) from marine bacteria to human enteric bacteria was examined by a filter-mating method. Vibrio spp., Lactococcus garvieae, Bacillus spp., Lactobacillus sp., and Paenibacillus sp. were used as donors, and Escherichia coli JM109 and Enterococcus faecalis JH2-2 were used as recipients. The combination of Vibrio spp. and E. coli resulted in 5/68 positive transconjugants with a transfer rate of 10⁻⁷ to 10⁻³; however, no transfer was observed with E. faecalis. In case of L. garvieae and E. faecalis, 6/6 positive transconjugants were obtained with a transfer rate of 10⁻⁶ to 10⁻⁵; however, no transfer was observed with E. coli. The tet(M) gene of Bacillus, Lactobacillus, and Paenibacillus were not transferred to either E. coli or E. faecalis. tet(M) transfer was confirmed in positive E. coli and E. faecalis transconjugants by polymerase chain reaction (PCR) and Southern hybridization. All the donor strains did not harbor plasmids, while they all harbored transposon Tn916. In the transconjugants, the transposon was not detected by PCR, suggesting the possible transfer of tet(M) from the marine bacterial chromosome to the recipient chromosome. This is the first report to show that tet(M) can be transferred from marine bacteria to human enteric bacteria in a species-specific manner.     

A nanoplex PCR assay for the rapid detection of vancomycin and bifunctional aminoglycoside resistance genes in <Emphasis Type="Italic">Enterococcus</Emphasis> species

Background  

Enterococci have emerged as a significant cause of nosocomial infections in many parts of the world over the last decade. The most common enterococci strains present in clinical isolates are E. faecalis and E. faecium which have acquired resistant to either gentamicin or vancomycin. The conventional culture test takes 2–5 days to yield complete information of the organism and its antibiotic sensitivity pattern. Hence our present study was focused on developing a nanoplex PCR assay for the rapid detection of vancomycin and bifunctional aminoglycoside resistant enterococci (V-BiA-RE). This assay simultaneously detects 8 genes namely 16S rRNA of Enterococcus genus, ddl of E. faecalis and E. faecium, aacA-aphD that encodes high level gentamicin resistance (HLGR), multilevel vancomycin resistant genotypes such as vanA, vanB, vanC and vanD and one internal control gene.     

Phenotypic and genotypic characterization of bacteriocins in clinical <Emphasis Type="Italic">enterococcal</Emphasis> isolates of Tunisia

The presence of bacteriocin structural genes (entA, entB, entP, entQ, entAS-48, entL50A/B, bac31, and cylL) encoding different bacteriocins (enterocin A, enterocin B, enterocin P, enterocin Q, enterocin AS-48, enterocin L50A/B, bacteriocin 31 and cytolysin L, respectively), and the production of bacteriocin activity were analysed in 139 E. faecalis and 41 E. faecium clinical isolates of Tunisia. Forty-eight of 139 E. faecalis isolates (34%) and 7 of 41 of E. faecium isolates (17%) were bacteriocin producers. Sixty-two per cent of the bacteriocin-producing enterococci showed inhibitory activity against L. monocytogenes. Different combinations of entA, entB, entP, and entL50A/B genes were detected among the seven bacteriocin-producer E. faecium isolates, and more that one gene were identified in all the isolates. The entA gene was associated in most of the cases with entB gene in E. faecium isolates. Cyl _LS were the unique genes detected among E. faecalis (in 24 of 48 bacteriocin-producer isolates, 50%). A β-hemolytic activity was demonstrated in 19 of the 24 cyl _LS -positive E. faecalis isolates (79%), this activity being negative in the remaining five isolates. The presence of different bacteriocin structural genes and the production of antimicrobial activities seems to be a common trait of clinical enterococci.     

<Emphasis Type="Italic">Anaplasma phagocytophilum</Emphasis> infection in a multi-species deer community in the New Forest,England

The tick-transmitted Anaplasma phagocytophilum has been recorded in a range of mammal species and causes granulocytic ehrlichiosis in humans, horses, and companion animals as well as tick-borne fever in ruminants. Although deer and other ruminant species are known to be natural hosts, the distribution among sympatric deer populations is unexplored. Blood from 80 deer of four species were screened using an A. phagocytophilum-specific real-time polymerase chain reaction. Overall, 29% (19–40) of deer tested positive. Fallow deer (Dama dama), the most numerous species, had significantly lower prevalence (21%) than roe (Capreolus capreolus), red (Cervus elaphus), or sika (Cervus nippon) deer (average 50%). It is suggested that patterns of habitat use influence infection levels in different deer species. The role of deer as reservoirs of anaplasmosis remains unknown; however, prevalence in deer could be a useful index of local infection pressure and the risk of disease in domestic animals and humans.     

Tick burden on European roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>)

In our study we assessed the tick burden on roe deer (Capreolus capreolus L.) in relation to age, physical condition, sex, deer density and season. The main objective was to find predictive parameters for tick burden. In September 2007, May, July, and September 2008, and in May and July 2009 we collected ticks on 142 culled roe deer from nine forest departments in Southern Hesse, Germany. To correlate tick burden and deer density we estimated deer density using line transect sampling that accounts for different detectability in March 2008 and 2009, respectively. We collected more than 8,600 ticks from roe deer heads and necks, 92.6% of which were Ixodes spp., 7.4% Dermacentor spp. Among Ixodes, 3.3% were larvae, 50.5% nymphs, 34.8% females and 11.4% males, with significant seasonal deviation. Total tick infestation was high, with considerable individual variation (from 0 to 270 ticks/deer). Adult tick burden was positively correlated with roe deer body indices (body mass, age, hind foot length). Significantly more nymphs were found on deer from forest departments with high roe deer density indices, indicating a positive correlation with deer abundance. Overall, tick burden was highly variable. Seasonality and large scale spatial characteristics appeared to be the most important factors affecting tick burden on roe deer.     

Inhibitory activity of probiotics <Emphasis Type="Italic">Streptococcus phocae</Emphasis> PI80 and <Emphasis Type="Italic">Enterococcus faecium</Emphasis> MC13 against Vibriosis in shrimp <Emphasis Type="Italic">Penaeus monodon</Emphasis>

Occurrence of widespread epizootics among larval and cultured shrimp has put on viable preventive approaches such as application of probiotics on a high priority in aquaculture. In the present study, four probiotics bacteria were isolated from marine fish and shrimp intestine based on the antagonistic activity and nonpathogenic to the host. The isolates of probiotics strains Streptococcus phocae PI80, Enterococcus faecium MC13, Lactococcus garvieae LC149, B49 and one commercial probiotics (ECOFORCE) were fed to post larvae of Penaeus monodon obtained from two different hatcheries to analyze the growth and protection against Vibrio harveyi and V. parahaemolyticus. Growth of P. monodon post larvae fed with probiotic strain S. phocae PI80 was significantly (P < 0.001) higher when compared with control and other three strains in both experiments. The treatment of post larvae with B49 reduced the growth as well as Specific growth rate. Among the three probiotic strains S. phocae PI80 and E. faecium MC13 have effectively inhibited the pathogens. In experiment I high survival (92%) were observed in S. phocae PI80 treated post larvae when challenged with Vibrio harveyi followed by E. faecium MC13 (84%), B49 (76%) and ECOFORCE (68%) but PI80 did not protect the post larvae in the same experiment when they were exposed to V. parahaemolyticus. The probiotic isolate of MC13 has protected the post larvae against V. parahaemolyticus when compared to other probiotics and control. Similarly in the second experiment feeding of S. phocae enhanced the survival of larvae when challenged with V. harveyi. The laboratory studies proved that bacterial probionts S. phocae and E. faecium isolated from shrimp and brackishwater fish has potential applications for controlling pathogenic vibriosis in shrimp culture.     

<Emphasis Type="Italic">Anaplasma phagocytophilum</Emphasis> and other tick-borne bacteria in wild animals in western Slovakia

Tick-borne bacterial zoonoses of livestock and free-ranging ungulates caused by Anaplasma spp. are common in Central Europe. The aim of this study was to analyze the prevalence of Anaplasma phagocytophilum and other tick-borne bacteria in wild animals from western Slovakia. Infection with A. phagocytophilum was recorded in 62.86% of analyzed roe deer (Capreolus capreolus), in two red deer (Cervus elaphus) and two wild boars (Sus scrofa). Dermacentor reticulatus and Ixodes ricinus ticks collected on red deer were not A. phagocytophilum-infected. However, spotted fever group rickettsiae were detected in ticks collected from red deer. High prevalence of A. phagocytophilum in roe deer as well as positive red deer and wild boars suggest the occurrence of natural foci in western Slovakia.     

Molecular diversity and transferability of the tetracycline resistance gene <Emphasis Type="Italic">tet</Emphasis>(M), carried on Tn<Emphasis Type="Italic">916-1545</Emphasis> family transposons,in enterococci from a total food chain

In the present study, 20 enterococci belonging to the species Enterococcus faecalis (12 strains), Enterococcus faecium (4), Enterococcus durans (2), Enterococcus hirae (1) and Enterococcus mundtii (1) and originating from a total production chain of swine meat commodities were analysed to investigate the diversity of their tetracycline resistance gene tet(M). PCR–RFLP and sequence analysis showed that the tet(M) gene of most strains can be correlated with the Tn916 transposon. Conversely, tet(M) of six E. faecalis and the E. hirae strain, all isolated from pig faecal samples, may be associated with previously undescribed members of the Tn916-1545 transposon family. In vitro filter conjugation trials showed the ability of 50% of the enterococcal strains, including E. mundtii, to transfer the tet(M) gene (and the associated Tn916 and new transposons) to E. faecalis or Listeria innocua recipient strains. tet(M) gene transfer to L. innocua recipient was also directly observed in meat food products. Collectively, these sequence and conjugation data indicate that various transposons can be responsible of the spread of tetracycline resistance in enterococci and validate the opinion that Enterococcus species are important sources of antibiotic resistance genes for potentially pathogenic bacteria occurring in the food chain. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Description and epidemiological implications of <Emphasis Type="Italic">S. scabiei</Emphasis> infection in roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>) originating from chamois (<Emphasis Type="Italic">Rupicapra rupicapra</Emphasis>)

The authors describe a case of Sarcoptes scabiei transmission from a chamois (Rupicapra rupicapra) kid to three roe deer (Capreolus capreolus) fawns kept in captive cohabitation in a wildlife rehabilitation centre for approximately 4 months. Symptoms in the two male fawns started developing 1 week after skin lesions were noticed in the kid, whereas a delayed (75 days later) appearance of scabies signs was observed in the female fawn. A severe generalised form of scabies rapidly developed in a male fawn, but lesions in the other two healed after triple inoculation of ivermectin at 15 days intervals. These roe deer were monitored for specific anti-S. scabiei antibodies with an immunoblotting technique. The strongest antibody response was exhibited during the clinical phase of the infection and then rapidly declined post-treatment. Interestingly, the female fawn developed immunoglobulin G to S. scabiei proteins more than 2 months before the onset of clinical scabies. Since all captive roe deer appeared sensitive to infection with S. scabiei var. rupicaprae, the authors hypothesise that the sporadic frequency of spontaneous scabies in this Cervid host may be attributed to avoidance of direct contacts with moribund or recently dead scabietic chamois, and/or to a self-limiting (and therefore difficult to detect) course of the disease after infrequent infectious contacts and/or exposure to lower infectious doses than in the described episode.     

Wild black-headed gulls (<Emphasis Type="Italic">Larus ridibundus</Emphasis>) as an environmental reservoir of <Emphasis Type="Italic">Salmonella</Emphasis> strains resistant to antimicrobial drugs

Salmonella were isolated from black-headed gulls (Larus ridibundus) in six locations in the Czech Republic from 1984 to 2005 (Chropyně and Nymburk in 1984–1986; Nové Mlyny, Bartošovice, and Hodonín in 1991–1994; and Nové Mlyny, Bartošovice, and Ostrava in 2005). Antimicrobial susceptibility was determined in 12 antimicrobial drugs using disk diffusion. Although 95% of Salmonella isolates (197 out of 207) were pansusceptible, the prevalences of resistance increased significantly from 1 (2%) out of 59 isolates in 1984–1986 and 3 (3%) out of 100 isolates in 1991–1994 to 6 (13%) out of 48 isolates in 2005. Furthermore, in 2005, two isolates were nalidixic acid-resistant and one isolate was multidrug-resistant Salmonella Typhimurium DT 104. These findings suggest that the occurrence of salmonellae in black-headed gulls depends to a large extent on the contamination where the gulls feed and possibly reflects the dissemination of these strains among farm animals and humans. Black-headed gulls may also become infected with resistant Salmonella and thus pose a potential risk of Salmonella contamination of surface water and animal feeds, and consequently dissemination.     

Viability and survival capability of quinolone-resistant uropathogenic <Emphasis Type="Italic">Escherichia coli</Emphasis>

Uropathogenic strains of E. coli isolated from urine of patients with urinary tract infections were tested for antibiotic sensitivity using bio-Merieux kits and ATB-UR 5 expression system. The virulence of strains was evaluated by serum bactericidal assay, macrophage “killing” and bacterial adhesive tests. Survival capability of strains was assessed under starvation in saline. The results showed that quinolone-resistant uropathogenic strains of E. coli exhibit significantly reduced adhesive potential but relatively high resistance to serum and macrophage bactericidity. In contrast to laboratory strains, the quinolone-resistant uropathogenic clinical isolate demonstrated increased viability during starvation in saline. Our study suggests that quinolone-resistant uropathogenic strains are highly adaptable clones of E. coli, which can exhibit compensatory viability potential under unfavorable conditions. The clinical occurrence of such phenotypes is likely to contribute to the survival, persistence and spread strategy of resistant bacteria.