Leclercia adecarboxylata isolation: case reports and review

Leclercia adecarboxylata in a Patient With Newly Diagnosed Chronic Lymphocytic Leukemia

Leclercia adecarboxylata is a Gram-negative bacillus commonly seen in immunocompromised individuals and often misdiagnosed as Escherichia coli. L. adecarboxylata is an opportunistic pathogen found in aquatic environments. It is a nonfatal infection that has low virulence and endorses susceptibility to many common antibiotics. We report a case of a 53-year-old immunocompromised male who was managed for L. adecarboxylata bacteremia.

Resistance phenotype and virulence potential of Leclercia adecarboxylata strains isolated from different sources

Introduction. Leclercia adecarboxylata is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted L. adecarboxylata as an emerging pathogen harbouring virulence and resistance determinants.Gap statement. Little information exists on virulence and resistance determinants in L. adecarboxylata strains isolated from environmental, food, and clinical samples.Aim. To determine the presence of resistance and virulence determinants and plasmid features in L. adecarboxylata strains isolated from environmental, food, and clinical samples, as well as their phylogenetic relationship.Results. All strains tested showed resistance to β-lactams and quinolones but were sensitive to aminoglycosides and nitrofurans. However, even though fosfomycin resistance is considered a characteristic trait of L. adecarboxylata, the resistance phenotype was only observed in 50 % of the strains; bla TEM was the most prevalent BLEE gene (70 %), while the quinolone qnrB gene was observed in 60 % of the strains. Virulence genes were differentially observed in the strains, with adhesion-related genes being the most abundant, followed by toxin genes. Finally, all strains carried one to seven plasmid bands ranging from 7 to 125 kbps and harboured several plasmid addiction systems, such as ParDE, VagCD, and CcdAB in 80 % of the strains.Conclusions. L. adecarboxylata is an important emerging pathogen that may harbour resistance and virulence genes. Additionally, it has mobilizable genetic elements that may contribute to the dissemination of genetic determinants to other bacterial genera.

Genomic insights of Leclercia adecarboxylata strains linked to an outbreak in public hospitals in Mexico

BACKGROUND

Leclercia adecarboxylata is a bacteria closely related to Escherichia coli according to its biochemical characteristics and is commonly considered non-pathogenic although a growing number of publications classify it as an emerging pathogen. Fosfomycin resistance is a common trait for L. adecarboxylata encoded by fosA^LA gene.

OBJECTIVE

To analyze genomic traits of sixteen L. adecarboxylata strains isolated from blood culture and a bottle of total parenteral nutrition.

METHODS

Twenty-eight L. adecarboxylata strains isolated from blood culture and a bottle of total parenteral nutrition were identified biochemically with a Vitek ® automated system. The strains were phenotyped by their growth on Eosin Methylene Blue agar or MacConkey agar plates. Additionally, Pulsed field gel electrophoresis (PFGE) was performed to establish the clonal relationship. The genomic DNA of sixteen strains was obtained using a Qubit ® dsDNA HS Assay Kit and sequenced on an Illumina ® MiSeq instrument. Draft genomes were assembled using PROKKA and Rast. Assemblies were submitted to Resfinder and PathogenFinder from the Center for Genomic Epidemiology in order to find resistance genes and pathogenic potential. IslandViewer4 was also used to find Pathogenicity and Phage Islands. For identification of the fosA gene, manual curation and Clustal analysis was performed. A novel FosA variant was identified. Finally, phylogenetic analysis was performed using VAMPhyRE software and Mega X.

RESULTS

In this paper, we report the genomes of sixteen strains of Leclercia adecarboxylata causing an outbreak associated with parenteral nutrition in public hospitals in Mexico. The genomes were analyzed for genetic determinants of virulence and resistance. A high pathogenic potential (pathogenicity index 0.82) as well as multiple resistance genes including carbapenemics, colistin and efflux pumps were determined. Based on sequence analysis, a new variant of the fosA^LA gene was described. Finally, the outbreak was confirmed by establishing the clonal relationship among the sixteen genomes obtained.

CONCLUSIONS

Commensal strains of L. adecarboxylata may acquire genetic determinants that provide mechanisms of host damage and go unnoticed in clinical diagnosis. L. adecarboxylata can evolve in a variety of ways including the acquisition of resistance and virulence genes representing a therapeutic challenge in patient care.

Leclercia pneumoniae sp. nov., a bacterium isolated from clinical specimen in Leipzig, Germany

Strain 49125T was isolated from an infant with pneumonia and septicaemia at the Leipzig University Hospital. Phenotypic and genomic traits were investigated. The strain's biochemical profile and its MALDI-TOF spectrogram did not differ from comparative samples of Leclercia adecarboxylata , thus far the sole member of the Leclercia species. A circular genome with a size of 4.4 Mbp and a G+C content of 55.0 mol% was reconstructed using hybrid Illumina and Nanopore sequencing. Phylogenetic analysis was based on 172 marker genes and validated using a k-mer-based search against a large genome collection including subsequent in silico DNA–DNA hybridization. Whole genome average nucleotide identity to any described species was below 95%, suggesting that strain 49125T represents a new species, for which we propose the name Leclercia pneumoniae sp. nov. with the type strain 49125T (=LMG 32245T=DSM 112336T).

Leclercia adecarboxylata as Emerging Pathogen in Human Infections: Clinical Features and Antimicrobial Susceptibility Testing

(1) Background: Leclercia adecarboxylata (L. adecarboxylata) is a gram-negative bacillus of the Enterobacteriaceae family, which is uncommonly isolated from clinical specimens. L. adecarboxylata is considered as an aquatic opportunistic pathogen and most of the human infections are polymicrobial and usually occur in immunocompromised hosts. (2) Methods: In this retrospective study, we included all L. adecarboxylata strains since the introduction of MALDI-TOF MS in the Microbiology Department of Nord Franche-Comté Hospital, France (from 1 March 2015 to 31 July 2019). We studied demographic characteristics, comorbidities, characteristics of the current infection and outcome as well as antimicrobial susceptibility testing in all isolates. (3) Results: A total of 8 samples were identified (in 6 patients (4M/2F), with a recurrent L. adecarboxylata infection in 2 patients). The patients’ mean age was 66.2 years (range: 19–84). All patients were considered as immunocompetent, except a peritoneal dialysis patient with kidney transplantation. An exposition to an aquatic environment was identified in one patient. The most prevalent clinical feature was catheter-associated male urinary tract infection (in 3 cases) followed by ventilator-associated pneumonia (in 2 cases). One of 6 patients presented L. adecarboxylata bacteremia. L. adecarboxylata was part of a polymicrobial infection in 4 patients. The isolates showed a high susceptibility to all tested antibiotics, except one strain, which was resistant to fosfomycin. All patients with L. adecarboxylata infection were treated with antibiotics with a favorable outcome. (4) Conclusion: This study confirms the pathogenicity of L. adecarboxylata, even in immunocompetent patients, with a high susceptibility to antibiotics.

[Rare superinfection in a COVID-19 patient-A chronology]

Bei einem 55-jährigen Mann, der sich zur elektiven Ablation bei Vorhofflimmern in der Klinik befand, wurde nach einer Reanimationssituation auf der peripheren Station ein SARS-CoV-2-Abstrich positiv getestet. Anamnestisch gab es im Vorwege gesicherten Kontakt zu einem COVID-19-positiven Patienten. Im Verlauf entwickelte sich das Vollbild einer COVID-19-Pneumonie mit umfangreicher intensivmedizinischer Behandlung. Nach rund 2‑wöchiger Therapie musste das Weaning bei erneuter Verschlechterung abgebrochen werden, und es ergaben sich bei dem wiederholt hochseptischen Patienten mikrobiologische Nachweise einer Superinfektion mit Cryptococcus neoformans und später Leclercia adecarboxylata. Der Patient wurde erfolgreich behandelt und überlebte die Erkrankung.

A case of Leclercia adecarboxylata endocarditis in a 62-year-old man

Leclercia adecarboxylata is a motile, gram negative bacillus in the Enterobacteriaceae family that is a rarely isolated cause of disease, despite being ubiquitous in nature. A 2019 review article identified only 74 reported cases, most often in immunocompromised patients [1]. The organism is generally susceptible to most antibiotics although multiantibiotic resistant strains have been reported. We report a case of a 62-year-old Caucasian man with multiple co-morbidities treated for L. adecarboxylata endocarditis with intravenous ceftriaxone.

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.

Genome sequencing and analysis of plant growth-promoting attributes from Leclercia adecarboxylata

Plant growth-promoting bacteria are ecological alternatives for fertilization, mainly for gramineous. Since plant x bacteria interaction is genotype and strain dependent, searching for new strains may contribute to the development of new biofertilizers. We aim to characterize plant growth-promoting capacity of Leclercia adecarboxylata strain Palotina, formerly isolated by our group in corn. A single isolated colony was taken and its genome was sequenced using Illumina technology. The whole genome was compared to other Leclercia adecarboxylata strains, and their biological and growth-promoting traits, such as P solubilization and auxin production, were tested. Following that, a 4.8 Mb genome of L. adecarboxylata strain Palotina was assembled and the functional annotation was carried out. This paper is the first to report the genes associated with plant growth promotion demonstrating in vitro indole acid production by this strain. These results project the endophyte as a potential biofertilizer for further commercial exploitation.

Leclercia adecarboxylata Causing Spontaneous Bacterial Peritonitis in a Child with Nephrotic Syndrome: A Case Report and Review of Literature

Infection is an important complication of childhood nephrotic syndrome (NS) and spontaneous bacterial peritonitis (SBP) is a frequently encountered one. We present a 7-year-old boy with NS who had decreased urine output, generalized body swelling, and abdominal pain. Urine analysis showed proteinuria of 50 mg/m ² /d. Ascitic tap showed total leukocyte count of 100 cells/mm ³ , sugar of 67 mg/dL, and protein of 1.1 g/dL. Gram stain revealed gram-negative bacilli with pus cells and culture grown Leclercia adecarboxylata (LAD). LAD was identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) with an identification score of 2.0. The organism showed good susceptibility to common antibiotics. The boy had no direct contact with livestock and the source of infection remains speculative. Devitalized skin because of massive edema seems to be the most plausible site of entry for the organism. Our patient was started on ceftriaxone and improved. LAD is a rare opportunistic pathogen, which belongs to Enterobacteriaceae and usually causes soft tissue infections. As far as we know, this is the first case where it has caused peritonitis in a child with NS. We also reviewed other pediatric cases.

Leclercia adecarboxylata: An Emerging Pathogen Among Pediatric Infections

Leclercia adecarboxylata is a gram-negative bacillus of the Enterobacteriaceae family. It is a rare human pathogen that is often acquired via wound and/or contact with aquatic environment. Although multiple cases of L. adecarboxylata infections are described in the adult population, few have been documented in pediatrics. We will present two cases of L. adecarboxylata infections in the pediatric population. The first is a case of cellulitis in an 11-year-old male patient after a penetrating wound. The second is a first-documented urinary tract infection in a 16-year-old male patient with chronic kidney disease. Both patients were successfully treated with antibiotics and surgical intervention, if necessary. These cases highlight the growing emergence of this bacterium in the pediatric population and the need to become more aware of its threat even in patients who are immunocompetent.

First Report of Coexistence of Three Different MDR Plasmids, and That of Occurrence of IMP-Encoding Plasmid in Leclercia adecarboxylata

Three different MDR plasmids p16005813A, p16005813B, and p16005813C, which carried a total of 18 non-redundant resistance genes or gene loci, were identified in a single clinical isolate of Leclercia adecarboxylata. The p16005813A backbone showed very low levels of identity to all DNA sequences available in public databases and carried a repA gene that could not assigned into any of known incompatibility groups. The IncFII-family p16005813B and pECAZ161_KPC had essentially identical backbones. p16005813C belonged to an IncR single-replicon plasmid. p16005813A, p16005813B, and p16005813C harbored three different novel MDR regions as their sole accessory modules. The MDR region of p16005813B manifested as Tn6505, which was generated from insertion of bla_IMP–8-carrying In655 instead of In4 into the Tn1696 backbone. Other key antibiotic resistance elements included Tn2, IS26–mph(A)–mrx–mphR(A)–IS6100 unit, chrA region, In27, and aacC2–tmrB region in the MDR region of p16005813A, and ΔTn9 carrying catA1, In609, and IS26–tetA(C)–tetR(C)–IS26 unit in the MDR region of p16005813C. This was the first report of coexistence of three different MDR plasmids, and that of occurrence of IMP-encoding plasmid and bla_IMP–8 gene in L. adecarboxylata.

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.

Peritonitis from Leclercia adecarboxylata: An emerging pathogen

Leclercia adecarboxylata can be misidentified as Escherichia coli, due to similar biochemical properties. Automated identification systems and mass spectrometry play a very critical role in isolating atypical organisms like L adecarboxylata. General guidelines recommend treating L adecarboxylata peritonitis for 3 weeks without removal of peritoneal dialysis catheter.

Genomic Analysis of Hospital Plumbing Reveals Diverse Reservoir of Bacterial Plasmids Conferring Carbapenem Resistance

The hospital environment is a potential reservoir of bacteria with plasmids conferring carbapenem resistance. Our Hospital Epidemiology Service routinely performs extensive sampling of high-touch surfaces, sinks, and other locations in the hospital. Over a 2-year period, additional sampling was conducted at a broader range of locations, including housekeeping closets, wastewater from hospital internal pipes, and external manholes. We compared these data with previously collected information from 5 years of patient clinical and surveillance isolates. Whole-genome sequencing and analysis of 108 isolates provided comprehensive characterization of bla_KPC/bla_NDM-positive isolates, enabling an in-depth genetic comparison. Strikingly, despite a very low prevalence of patient infections with bla_KPC-positive organisms, all samples from the intensive care unit pipe wastewater and external manholes contained carbapenemase-producing organisms (CPOs), suggesting a vast, resilient reservoir. We observed a diverse set of species and plasmids, and we noted species and susceptibility profile differences between environmental and patient populations of CPOs. However, there were plasmid backbones common to both populations, highlighting a potential environmental reservoir of mobile elements that may contribute to the spread of resistance genes. Clear associations between patient and environmental isolates were uncommon based on sequence analysis and epidemiology, suggesting reasonable infection control compliance at our institution. Nonetheless, a probable nosocomial transmission of Leclercia sp. from the housekeeping environment to a patient was detected by this extensive surveillance. These data and analyses further our understanding of CPOs in the hospital environment and are broadly relevant to the design of infection control strategies in many infrastructure settings.

Carbapenemase-producing organisms (CPOs) are a global concern because of the morbidity and mortality associated with these resistant Gram-negative bacteria. Horizontal plasmid transfer spreads the resistance mechanism to new bacteria, and understanding the plasmid ecology of the hospital environment can assist in the design of control strategies to prevent nosocomial infections. A 5-year genomic and epidemiological survey was undertaken to study the CPOs in the patient-accessible environment, as well as in the plumbing system removed from the patient. This comprehensive survey revealed a vast, unappreciated reservoir of CPOs in wastewater, which was in contrast to the low positivity rate in both the patient population and the patient-accessible environment. While there were few patient-environmental isolate associations, there were plasmid backbones common to both populations. These results are relevant to all hospitals for which CPO colonization may not yet be defined through extensive surveillance.

Genetic characterization of two fully sequenced multi-drug resistant plasmids pP10164-2 and pP10164-3 from Leclercia adecarboxylata

We previously reported the complete sequence of the resistance plasmid pP10164-NDM, harboring bla_NDM (conferring carbapenem resistance) and ble_MBL (conferring bleomycin resistance), which is recovered from a clinical Leclercia adecarboxylata isolate P10164 from China. This follow-up work disclosed that there were still two multidrug-resistant (MDR) plasmids pP10164-2 and pP10164-3 coexisting in this strain. pP10164-2 and pP10164-3 were completely sequenced and shown to carry a wealth of resistance genes, which encoded the resistance to at least 10 classes of antibiotics (β-lactams. macrolides, quinolones, aminoglycosides, tetracyclines, amphenicols, quaternary ammonium compounds, sulphonamides, trimethoprim, and rifampicin) and 7 kinds of heavy mental (mercury, silver, copper, nickel, chromate, arsenic, and tellurium). All of these antibiotic resistance genes are associated with mobile elements such as transposons, integrons, and insertion sequence-based transposable units, constituting a total of three novel MDR regions, two in pP10164-2 and the other one in pP10164-3. Coexistence of three resistance plasmids pP10164-NDM, pP10164-2 and pP10164-3 makes L. adecarboxylata P10164 tend to become extensively drug-resistant.