Isolations of Leclercia adecarboxylata from a patient with a chronically inflamed gallbladder and from a patient with sepsis without focus

Description of a novel species of Leclercia, Leclercia tamurae sp. nov. and proposal of a novel genus Silvania gen. nov. containing two novel species Silvania hatchlandensis sp. nov. and Silvania confinis sp. nov. isolated from the rhizosphere of oak

BACKGROUND

Acute Oak Decline (AOD) is a decline disease first reported on native oaks in the UK, but in recent years reports from further afield such as Europe and the Middle East, indicate that the distribution and host range is increasing at an alarming rate. The stem weeping symptoms of the disease partially develop due to polymicrobial-host interaction, caused by several members of the order Enterobacterales. While investigating the rhizosphere soil of AOD-unaffected trees, termed 'healthy' trees, and diseased oaks suffering from Acute Oak Decline (AOD), an enrichment method designed for enhanced recovery of Enterobacterales led to the recovery of several isolates that could not be classified as any existing species. These isolates showed a close relationship to the genus Leclercia, of which both species are of clinical importance, but the type species Leclercia adecarboxylata also displays plant growth-promoting properties in the rhizosphere.

RESULTS

Partial sequencing of four housekeeping genes revealed similarity to the genus Leclercia with varying degrees of relatedness. As such a complete polyphasic approach was used to determine the true taxonomic position of these isolates. This involved whole genome sequencing, phylogenomic analysis, phylogenetic analysis of both the 16S rRNA and four housekeeping gene sequences, combined with phenotypic testing and fatty acid analysis. Both the phylogenomic and phylogenetic analyses separated the isolates into four clusters, two of which were contained in the Leclercia clade. The remaining two clusters formed a separate lineage far removed from any currently defined species. Further investigation into the role of the isolates as plant growth-promoting bacteria as well as plant pathogens was investigated computationally, revealing a number of plant growth-promoting traits as well as virulence genes related to motility, adhesion and immune modulation.

CONCLUSION

Based on the genotypic and phenotypic data presented here, these isolates could be differentiated from each other and their closest neighbours. As such we propose the description of Leclercia tamurae sp. nov. (type strain H6S3^T = LMG 32609^T = CCUG 76176^T), Silvania gen. nov., Silvania hatchlandensis sp. nov. (type strain H19S6^T = LMG 32608^T = CCUG 76185^T) and Silvania confinis sp. nov. (type strain H4N4^T = LMG 32607^T = CCUG 76175^T). Due to their interesting protein annotations and alignments, these species warrant further investigation for their role in relation to plant health.

Leclercia adecarboxylata Bacteremia without a Focus in a Non-Immunosuppressed Patient

BACKGROUND Leclercia adecarboxylata is a gram-negative rod, which is normally found in water and food. It is an emerging pathogen that affects immunocompromised patients, including patients with hematological malignancies or those receiving chemotherapy. Generally, L. adecarboxylata is considered a low-virulence pathogen with an excellent susceptibility profile, but some strains may be resistant to multiple antibiotics, such as b-lactams. Moreover, L. adecarboxylata is usually isolated as a part of polymicrobial cultures in immunocompetent individuals, but there have been cases where it was the only isolate. CASE REPORT A 74-year-old woman who was non-immunosuppressed and had multiple comorbidities was admitted with acute decompensated heart failure due to pneumonia. She was treated with multiple courses of antibiotics including amoxicillin-clavulanate and ciprofloxacin for pneumonia, but her infection worsened, and she had cardiopulmonary arrest. After resuscitation, she was stable for several days but suddenly became confused and hypotensive. The septic screen showed L. adecarboxylata bacteremia without a clear source, which was treated successfully with meropenem for 14 days. After the meropenem course, the patient developed diarrhea and was found to have severe Clostridium difficile infection. She did not respond to oral vancomycin and intravenous metronidazole and died. CONCLUSIONS This case illustrated an infection in a non-immunosuppressed individual by an organism that is considered an opportunistic pathogen, mainly affecting immunocompromised patients. The patient's blood culture grew L. adecarboxylata, which was sensitive to all antibiotics but resolved with meropenem treatment. Owing to increasing L. adecarboxylata infections, we recommend further studies to understand the organism's pathogenesis, risk factors, and resistance pattern.

Identification and characterization of an amidase from Leclercia adecarboxylata for efficient biosynthesis of L-phosphinothricin

L-phosphinothricin (L-PPT) is an important broad-spectrum herbicide with expanding utilization because it is environmentally benign. A strain Leclercia adecarboxylata ZJB-17008 with capability of catalyzing rac-4-(hydroxy(methyl)phosphoryl)-2-(2-phenylacetamido) butanoic acid (rac-S) to L-PPT was screened and identified, from which an amidase (La-Ami) was cloned and secretory expressed in Bacillus subtilis WB 800 for the bioproduction of L-PPT. The recombinant La-Ami exhibited an excellent enantioselectivity (99.9% ee) and remarkable thermostability with a half-life of 19.8 h at 50 °C. Furthermore, La-Ami displaying a high space-time yield of 787.2 g L^-1 d^-1 at 50 °C and pH 8.5 under the rac-S concentration of 500 mM (150 g L^-1). The finally refined L-PPT was obtained with a purity of 99% and a total yield reached 90%. These results implying that this secretory expressed amidase La-Ami is possible to be applied in the large-scale bioproduction of L-PPT.

Leclercia adecarboxylata Cholecystitis with Septic Shock in Immunocompetent Patient

L. adecarboxylata is a Gram-negative rod previously named Escherichia adecarboxylata, isolated as normal flora in the gut of animals including human stool. Most reported cases refer to immunocompromised patients with polymicrobial infections and water environments. Here we present a case of 51-year-old immunocompetent female presented with nausea, vomiting, malaise, and subjective fever for few days. On examination, she was drowsy but arousable and oriented to person, place, time, and situation. Her abdomen was tender globally and more tender in the epigastric area. Vitals showed a temperature of 37°C, pulse of 110 beats/min, blood pressure of 75/50 mmHg, and oxygen saturation of 91% on room air. An HIV panel and hepatitis panel were negative. Liver and gallbladder ultrasound was performed, revealing multiple nonmobile stones with shadowing noted within the gallbladder sac, a thickened gallbladder wall, and a moderate amount of pericholecystic fluid. Broad spectrum antibiotics, crystalloid fluids, and vasopressors were initiated. A few hours after admission she developed respiratory failure for which she underwent endotracheal intubation. An ultrasound guided gallbladder drain was performed. Culture of the biliary fluid yielded pure growth of pan-sensitive L. adecarboxylata; antibiotics were narrowed accordingly. The patient was on the maximum doses of vasopressin, norepinephrine, and epinephrine with a blood pressure of 75/45 and a mean arterial pressure of 51. She passed away on the fourth day of admission.

Escherichia hermannii Infections in Humans: A Systematic Review

Eshcerichia hermannii is a member of the Enterobacteriaceae, first described in 1982 and reclassified as a distinct species in the Escherichia genus after identifying biochemical and genomic differences from E. coli. It is a rare cause of human infections and is supposed to be a co-infector rather than an autonomous cause of infection. The aim of this systematic review was to record and evaluate all available evidence regarding human infections by E. hermannii. A systematic review of PubMed (through 21 December 2018) for studies providing epidemiological, clinical, and microbiological information, as well as treatment data and outcomes of E. hermannii infections was performed. A total of 16 studies, containing data of 17 patients, were eventually included in the analysis. The most common E. hermannii infections were bacteremias, urinary tract, and central nervous system infections. The complication rate, like the occurrence of sepsis, was high. Cephalosporins and aminoglycosides were the most common agents used for treatment. This systematic review describes bacterial infections by E. hermannii and provides information on the epidemiology, clinical presentation, antibiotic resistance, treatment, and outcomes associated with these infections.

Leclercia adecarboxylata: a case report and literature review of 74 cases demonstrating its pathogenicity in immunocompromised patients

Leclercia adecarboxylata is a Gram-negative bacterium belonging to the family Enterobacteriaceae. It has been described as an emerging human pathogen with the potential to cause severe infection in immunocompromised patients. The aim of this study was to describe a clinical case of infection with L. adecarboxylata and give a review of previous reports on infection. We report the presence of L. adecarboxylata in a patient initially admitted to our hospital for a lung transplant. She had diarrhoea, urinary tract infection and pneumonia caused by L. adecarboxylata. The isolate was resistant to trimethoprim-sulfamethoxazole and susceptible to 15 other antibiotics tested. The literature search for previous reports of infection with L. adecarboxylata resulted in 61 publications describing 74 cases. Bacteremia and wound infections were most often described, and only a few cases were fatal. L. adecarboxylata was most often found as a monomicrobial infection in immunocompromised patients, and as part of a polymicrobial infection in immunocompetent patients. The previously described isolates showed a high susceptibility to antibiotics, and treatment was efficient in most cases. Due to similarities in metabolic products, L. adecarboxylata might have been mistaken as Escherichia spp., but with new identification methods such as MALDI-TOF MS, it is possible to obtain a certain identification.

Isolation and characterization of multidrug-resistant Leclercia species from animal clinical case

Leclercia adecarboxylata, a Gram-negative bacillus of family Enterobacteriaceae, is an uncommonly identified pathogen isolated from environmental and clinical specimens. Most of the human infections are polymicrobial and commonly occur in immunocompromised hosts, although nosocomial infections in immunocompetent hosts have been documented. Here, we describe the case of isolation of Leclercia species as polymicrobial infection from bovine suffering from respiratory distress in Chhattisgarh state of India. The isolates were identified by their phenotypes, 16S rDNA sequencing and MALDI-TOF-MS. The isolate was found to be resistant to aminoglycosides and fluoroquinolone antibiotics and intermediate resistant to cephalosporins and evidenced for uncertain clinical relevance and could act as hidden source of public health hazard.

SIGNIFICANCE AND IMPACT OF THE STUDY

Leclercia adecarboxylata is a rarely reported human pathogen. We report here the case from bovine suffering from respiratory distress; the sample yielded Leclercia species as polymicrobial culture. The isolate was found to be multidrug resistant and evidenced for uncertain clinical relevance and could act as hidden source of public health hazard. The limited literature available on this organism is reviewed, and the potential implications of findings are discussed. To the best of our knowledge, this is the first report of isolation and characterization of multidrug-resistant Leclercia species from animal clinical case from India.

Hospital-acquired pneumonia due to Leclercia adecarboxylata in a neurosurgical centre

Leclercia adecarboxylata, a gram-negative bacillus of the Enterobacteriaceae family, is an uncommonly identified human pathogen. The organism has been reported worldwide and isolated from various environmental sources. Most human infections are polymicrobial and commonly occur in immunocompromised hosts, although nosocomial infections in immunocompetent hosts have been documented. We describe three case reports of L. adecarboxylata isolation from cases of hospital acquired pneumonia admitted to a tertiary care center for neurosurgical care.

Leclercia adecarboxylata isolation: case reports and review

Leclercia adecarboxylata is usually isolated as a part of polymicrobial cultures in immunocompetent patients, and as a pure culture in immunocompromised persons. Although generally sensitive to most antibiotics, there are reports of resistant strains. Two case reports of L. adecarboxylata isolation in the lab in pure culture in immunocompetent persons are presented here, L. adecarboxylata being isolated from a vaginal swab in the first case and from a gluteal abscess in the second case. Both the isolates were sensitive to most of the antibiotics tested.

Leclercia adecarboxylata Bacteremia in a Patient with Ulcerative Colitis

Patients with inflammatory bowel disease (IBD) are a high risk population for bacteremia. Derangement in the mucosal architecture of the gastrointestinal (GI) tract and frequent endoscopic interventions in immunocompromised individuals are considered primary causes. Isolation of opportunistic microorganisms from the bloodstream of IBD patients has been increasingly reported in recent years. Leclercia adecarboxylata is a ubiquitous, aerobic, motile, gram-negative bacillus. The human GI tract is known to harbor this rarely pathogenic microorganism. There are only a few case reports of bacteremia with this microorganism; the majority are either polymicrobial or associated with immunocompromised patients. We describe a case of monomicrobial L. adecarboxylata bacteremia in a 43-year-old female who presented with bloody diarrhea. Colonoscopy revealed diffuse colonic mucosal inflammation with numerous ulcers, and histopathology revealed crypt abscesses. Following an episode of rectal bleeding, two sets of blood cultures grew L. adecarboxylata, which was treated with intravenous ceftriaxone. After a complicated hospital course, she was eventually diagnosed with ulcerative colitis and enteropathic arthritis, treated with intravenous methylprednisolone, mesalamine, and infliximab which resulted in resolution of her symptoms. In our previously immunocompetent patient, derangement of the gut mucosal barrier was the likely cause of bacteremia, yet performing endoscopic intervention may have contributed to bacterial translocation.

Pyelonephritis Caused Solely by Escherichia hermanii

INTRODUCTION

In contrast with Escherichia coli, the association of E. hermanii with urinary tract infections has not been described.

CASE PRESENTATION

In this case, E. hermanii was the sole isolate recovered from urine specimens of a pyelonephritis patient. The organism was found to be susceptible to piperacillin-tazobactam, ceftazidime, cefazolin, cefixime, aztreonam, gentamicin, tobramycin, imipenem, meropenem and amikacin, and resistant to amoxicillin. Antibiotic treatment was initiated with oral cefixime (400 mg every 24 hours). The symptoms were relieved within 72 hours after therapy. A urine sample was taken seven days after antibiotic therapy. E. hermanii was no longer isolated.

DISCUSSION

The present case demonstrates that the uropathogenic E. hermanii clone can cause destruction of the kidneys. During asymptomatic bacteriuria or cystitis, the bacteria remain in the urinary tract. Even when pyelonephritis develops, inflammatory response of the host is still restricted to the urinary tract. These signs mean that uropathogenic E. hermanii may be not very virulent.

Leclercia adecarboxylata bacteremia in a patient with long-term use of nonsteroidal anti-inflammatory drugs

Leclercia adecarboxylata, a ubiquitous Gram-negative bacillus, is generally viewed as an opportunistic pathogen because it is rarely cultured from clinical samples. Although rare, bacteremia due to L. adecarboxylata tends to occur in immunocompromised hosts and patients with systemic comorbidities. Only one case of bacteremia due to L. adecarboxylata has been reported in a previously healthy patient. We describe a male patient with an active peptic ulcer who developed L. adecarboxylata bacteremia after a long-term use of nonsteroidal anti-inflammatory drugs. The abdomen is believed to have been the most probable portal of entry. After appropriate medical management, the patient recovered without sequela.

Leclercia adecarboxylata and catheter-related bacteraemia: review of the literature and outcome with regard to catheters and patients

Infection is a common complication in patients carrying a central venous catheter (CVC) and is associated with increased morbidity and mortality. Leclercia adecarboxylata is an unusual but emerging pathogen in healthy and immunocompromised patients. We report a case of L. adecarboxylata bacteraemia in a patient with a haemodialysis tunnelled CVC. In accordance with the susceptibility to the tested antimicrobials, a long-course treatment with intravenous gentamicin plus amoxicillin-clavulanic acid and gentamicin-lock therapy was adopted. The patient had a full recovery and the catheter was not removed. We also performed a systematic PubMed/Medline and Scopus review of peer-reviewed English papers on L. adecarboxylata infections, focusing on bacteraemia in patients with different types of CVCs. Moreover, we suggest a treatment algorithm to preserve the patient and maintain the CVC.

Emerging Escherichia pathogen

Escherichia hermannii was first identified as a new species in 1982. It has rarely been reported as a human pathogen. We report the first case of E. hermannii as the sole pathogen in a catheter-related bloodstream infection.

Catheter-related bacteremia caused by multidrug-resistant Leclercia adecarboxylata in a patient with breast cancer

We report a multidrug-resistant strain of Leclercia adecarboxylata responsible for catheter-related bacteremia in a 47-year-old female with breast cancer. The isolated strain was resistant to several β-lactams, aminoglycosides, and folate pathway inhibitors and harbored bla(TEM-1) and bla(CTX-M) group 1 and intl1 genes (dfrA12-orfF-aadA2) as genetic determinants for resistance. Based on a review of the L. adecarboxylata literature, there have been only 4 reports of antibiotic-resistant strains. To our knowledge, this is the first report of an L. adecarboxylata strain with simultaneous resistance to β-lactams, aminoglycosides, and sulfonamides.

Leclercia adecarboxylata bacteremia in a trauma patient: case report and review of the literature

BACKGROUND

Leclercia adecarboxylata is a rarely described gram-negative pathogen. Since the advent of rapid molecular typing techniques, L. adecarboxylata has been described in 23 case reports, often associated with polymicrobial infections or in immunosuppressed hosts.

METHODS

A case is described and previous cases of L. adecarboxylata infection are reviewed.

CASE REPORT

A 55-year old male victim of trauma developed septic shock several days after presentation to the emergency department. Blood and central vein catheter cultures grew L. adecarboxylata; Haemophilus influenzae and Streptococcus pneumoniae were present in bronchoalveolar lavage samples. With aggressive hemodynamic and ventilator support in addition to antibiotic therapy, the patient cleared the catheter-related blood stream infection. After a challenging intensive care unit stay, the patient eventually was discharged to an inpatient rehabilitation unit.

CONCLUSION

An L. adecarboxylata catheter-related blood stream infection developed in the setting of both underlying immunosuppression and polymicrobial infection. As molecular typing techniques continue to improve, L. adecarboxylata is likely to be an increasingly recognized gram-negative pathogen. Interactions between L. adecarboxylata infection, immunosuppression, and polymicrobial infections remain to be elucidated.

Late-onset Leclercia adecarboxylata bacteraemia in a premature infant in the NICU

Late-onset sepsis is a unique entity in the neonatal intensive care unit (NICU), as organisms involved are, by definition, nosocomial. As such, a limited number of microbes are characteristically involved. Leclercia adecarboxylata is a gram-negative bacillus rarely cultured in a clinical context, with the few published cases primarily involving immunocompromised adults. We present an ex-26-week newborn girl who developed late-onset sepsis with Leclercia adecarboxylata bacteraemia in the NICU. The infection was successfully treated with gentamicin and cefotaxime. This is the fifth paediatric report of Leclercia adecarboxylata infection, and the first in a neonate. The case raises the possibility that prior courses of antibiotics may have predisposed this individual to a rare infection essentially limited to immunocompromised individuals.

CONCLUSION

Leclercia adecarboxylata is a rare infection, particularly in immunocompetent individuals. In neonates, the clinical course can be good with timely initiation of appropriate antibiotics.

Leclercia adecarboxylata cellulitis in a child with acute lymphoblastic leukemia

Leclercia adecarboxylata is a rare, gram-negative rod that has been infrequently reported in the literature. The organism has been documented to cause solitary infections in immunocompromised hosts and polymicrobial wound infections in the immunocompetent. We present a case of an 8-year-old boy with significant past medical history of acute lymphoblastic leukemia who developed cellulitis due to local infection by L. adecarboxylata. This case is presented to raise awareness of this rare organism's ability to cause common cutaneous disease, especially in the immunocompromised.

A case of Leclercia adecarboxylata endocarditis in a woman with endometrial cancer

Leclercia adecarboxylata, a motile, gram-negative bacillus of the enterobacteriaceae family, is rarely recovered as a pathogen. We report an exceptionally rare case of L. adecarboxylata endocarditis complicated by embolization of the kidney and spleen in a 48-year-old woman with endometrial cancer. After 4 weeks of antimicrobial treatment, she recovered without sequelae.

Prospective comparison of microbial culture and polymerase chain reaction in the diagnosis of corneal ulcer

PURPOSE

To compare polymerase chain reaction (PCR) to microbial culture for the detection and identification of bacterial and fungal pathogens in microbial keratitis.

DESIGN

Prospective cohort study.

METHODS

A total of 108 consecutive corneal ulcers were cultured and analyzed by PCR using pan-bacterial and pan-fungal primers. PCR products were cloned, sequenced, and compared to culture results using standard bioinformatics tools.

RESULTS

Of the 108 samples, 56 were culture-positive, 25 for bacteria and 31 for fungi; 52 were culture-negative. After eliminating false-positive PCR products, 94 of 108 were positive by PCR, 37 for bacteria and 57 for fungi. Nineteen of 25 bacterial culture-positive samples were positive by PCR, and 29 of 31 samples culture-positive for fungi were positive by PCR. The majority of sequenced PCR products matched the positive culture results. Of the 52 culture-negative samples, 46 (88%) yielded pathogen deoxyribonucleic acid (DNA) PCR products, 18 bacterial and 28 fungal. These represented a variety of species, including at least three novel previously uncultured microbes.

CONCLUSIONS

PCR detects microbial DNA in the majority of bacterial and fungal corneal ulcers, and identifies potentially pathogenic organisms in a high proportion of culture-negative cases. Yield and concordance with culture are higher for fungal than bacterial ulcers. Practical use of the technique is limited by artefactual amplification of nonpathogenic organisms. PCR may be used as an adjunct to culture to identify potential pathogens in microbial keratitis.

Escherichia hermannii as the sole isolate from a patient with purulent conjunctivitis

Escherichia hermannii was isolated in pure culture from a patient with acute purulent conjunctivitis after a minor ocular injury. This is the first report of E. hermannii isolated as the sole pathogen from an infected site without prior antibiotic exposure, confirming the pathogenic potential of the microorganism.

Composition of intestinal Enterobacteriaceae populations of healthy domestic pigs

In this study, the Enterobacteriaceae microbiota, including their diversity as well as the distribution of haemolytic and virulence gene-harbouring Escherichia coli of 56-day-old healthy piglets, was characterized. Both the composition and the diversity of Enterobacteriaceae populations varied considerably between individual pigs and intestinal sections. E. coli, Enterobacter cloacae, Citrobacter freundii and Klebsiella pneumoniae dominated the Enterobacteriaceae microbiota. However, mucosa-associated Enterobacteriaceae were scarce or in some cases undetectable. The majority of E. coli clones from the jejunum were also found in the colon, with up to 10 different E. coli clones in one intestinal section. Other Enterobacteriaceae species were represented by only one clone localized to one intestinal section. While several piglets did not harbour virulence gene-positive or haemolytic E. coli, such strains dominated intestinal sections of other animals. This study reveals that the diversity of intestinal Enterobacteriaceae is clearly individual. In general, Enterobacteriaceae do not appear to be a consistent fraction of the microbiota of the jejunum. High numbers of adherent bacteria do not appear to be essential for successful intestinal colonization, and E. coli clones do not necessarily colonize distinct intestinal sections based on the particular phylogenetic affiliation. Furthermore, dominance of haemolytic or virulence gene-positive E. coli does not correlate with disease. Finally, probiotic Enterococcus faecium feed supplementation does not affect the Enterobacteriaceae microbiota.

Isolation of Leclercia adecarboxylata from the blood culture of an asymptomatic platelet donor

BACKGROUND

Bacterial contamination of platelet (PLT) components is a leading cause of transfusion-related fatality. AABB and The College of American Pathologists require that blood centers and transfusion services have a process for detecting bacterial contamination in PLT products.

CASE REPORT

Leclercia adecarboxylata was isolated from the donated blood of a healthy, asymptomatic 61-year-old man. The PLT donation was collected by apheresis method and was separated into three daughter or split products. Samples from all three products tested positive for the presence of bacterial contamination. L. adecarboxylata was subsequently identified in two of three products. The blood donor's records were reviewed and the donor was interviewed by telephone. The only possible risk identified during the interview was a questionable contact dermatitis, away from the antecubital fossa, thought to be due to poison ivy exposure before the donation. All subsequent donations have tested negative for the presence of bacterial contamination. The organism is a Gram-negative bacillus variant of the Enterobacteriaceae family and known nosocomial isolate. It has been previously reported as a rarely isolated opportunistic pathogen mostly associated with patients having compromised immunity, chronic or inflammatory illness, catheter-related bacteremia, or mixed-bacterial wounds. L. adecarboxylata was originally identified in water, foods, and environment.

CONCLUSION

This is the first known report of isolation of L. adecarboxylata from the blood donation of an apparently healthy individual and could represent transient asymptomatic bacteremia or more likely contamination by epidermal flora. The organism may be underrecognized due to its close resemblance to Escherichia coli.

Natural antimicrobial susceptibility patterns and biochemical profiles of Leclercia adecarboxylata strains

Leclercia adecarboxylata is an opportunistic human pathogen that phenotypically resembles Escherichia coli. The natural susceptibilities of 101 Leclercia strains to 70 antimicrobial agents were investigated. MICs were determined with a microdilution procedure in cation-adjusted Mueller-Hinton broth (all strains) and IsoSensitest broth (some strains). Natural susceptibility patterns were assessed using German (DIN) standards (when applicable). In addition, biochemical properties recommended for the phenotypic identification of L. adecarboxylata were evaluated, applying two commercially available identification systems for Enterobacteriaceae and seven conventional tests. L. adecarboxylata strains were naturally sensitive to tetracyclines, aminoglycosides, all but two beta-lactams, quinolones, folate pathway inhibitors, chloramphenicol, nitrofurantoin and azithromycin. They were naturally resistant to penicillin G, oxacillin, erythromycin, roxithromycin, clarithromycin, ketolides, lincosamides, streptogramins, linezolid, glycopeptides, rifampicin, fusidic acid and fosfomycin. There were only minor medium-dependent differences in susceptibility to most antibiotics. Lysine decarboxylase, malonate assimilation and acid production from arabitol and cellobiose, but not from adonitol and sorbitol, allowed definitive separation of L. adecarboxylata from E. coli. The results of this study form a database that can be applied to validate forthcoming antibiotic susceptibility tests of L. adecarboxylata, and might contribute to its reliable identification. Susceptibility patterns did not indicate obvious therapeutic difficulties for treatment of Leclercia infections. Special attention should be paid to biochemically aberrant leclerciae. Apart from biochemical features, fosfomycin susceptibility might be useful to differentiate between L. adecarboxylata and E. coli.

Degradation of polycyclic aromatic hydrocarbons by a newly discovered enteric bacterium, Leclercia adecarboxylata

A bacterial strain, PS4040, capable of degrading polycyclic aromatic hydrocarbons for use as the sole carbon source was isolated from oily-sludge-contaminated soil. The 16S rRNA gene showed 98.8% homology to that of Leclercia adecarboxylata. Comparative molecular typing with the clinical strain of L. adecarboxylata revealed that there were few comigrating and few distinct amplimers among them.

Isolation from blood culture of a Leclercia adecarboxylata strain producing an SHV-12 extended-spectrum beta-lactamase

We report on the first isolation of an extended-spectrum beta-lactamase-producing Leclercia adecarboxylata strain from the bloodstream in a 58-year-old man with acute myeloid leukemia. The strain, resistant to ceftazidime, cefotaxime, and aztreonam, produces the SHV-12 beta-lactamase, one of the most common variants found in Italian nosocomial isolates of Enterobacteriaceae.