Klebsiella oxytoca Complex: Update on Taxonomy, Antimicrobial Resistance, and Virulence

Klebsiella oxytoca is actually a complex of nine species— Klebsiella grimontii , Klebsiella huaxiensis , Klebsiella michiganensis , K. oxytoca , Klebsiella pasteurii , Klebsiella spallanzanii , and three unnamed novel species. Phenotypic tests can assign isolates to the complex, but precise species identification requires genome-based analysis.

Ready-to-Eat Sandwiches as Source of Pathogens Endowed with Antibiotic Resistance and Other Virulence Factors

The aim of this study was to evaluate and characterize the bacterial load present in twenty-four Ready-To-Eat (RTE) sandwiches, purchased at refrigerated vending machines and supermarkets in the province of Modena (Italy). We isolated 54 bacterial strains, including pathogens of interest in food safety, such as Listeria, Staphylococcus, Enterococcus, Yersinia, Aeromonas and Acinetobacter spp. Phenotypic tests have been performed on these pathogens to detect the presence of virulence factors, such as gelatinase production and hemolytic capability. To test their antibiotic resistance features, the minimum inhibitory concentration (MIC) against eight commonly used antibiotics (Amikacin, Ciprofloxacin, Ampicillin, Oxacillin, Imipenem, Tetracycline, Erythromycin and Vancomycin) was also evaluated. The results showed that among the 54 isolates, fifty percent (50%) belonged to harmless microorganisms (Leuconostoc and Lactococcus), whereas the remaining fifty percent (50%) included pathogenic bacteria (Listeria ivanovii, Listeria monocytogenes, Staphylococcus aureus, Yersinia, and Citrobacter spp.), species responsible for pathologies often difficult to treat due to the presence of antibiotic resistance features. This study demonstrates the importance of thorough controls, both during the production and marketing of RTE food like sandwiches, to avoid reaching the infectious load and the onset of pathologies, particularly dangerous for old and immunocompromised patients.

A short report on the tumor suppressor role of BIRC7 in pancreatic cancer

<p>Pancreatic cancer (PC) is accepted to be an aggressive malignancy among all type of cancers due to its poor prognosis and high cancer-led mortality ratio mostly affecting male community in older age. Multiple genes are involved in PC initiation, progression and metastasis including K-RAS, CDKN2A, p53, SMAD4. Baculoviral IAP repeat containing 7 (BIRC7) commonly known as Livin, an inhibitor of apoptosis protein (IAP) involved in the inhibition of cell death via apoptosis by preventing caspase activity through various approaches. The biological role of BIRC7 was previously identified in multiple cancers but ill investigated in PC. In this study, we investigate the function role of BIRC7 in PC. Multiple phenotypic tests including wound healing assay, CCK8 assay, trans-well assay and colony formation assay was run to rule out BIRC7 gene effect on PC genesis. We for the first time indicated that, overexpression of BIRC7 significantly reduced the proliferation, development, progression and metastasis of PANC-1 cell <em>in vitro</em>. Therefore, we anticipated that BIRC7 gene is a suppressor gene and might be a suitable candidate gene for therapeutic purposes in PC.</p>

Molecular, phenotypical, and host-range characterization of Robbsia andropogonis strains isolated from Bougainvillea spp. in Mexico.

Characteristic leaf spot and blight symptoms caused by Robbsia andropogonis on bougainvillea plants were found in three locations in different provinces of Mexico from 2019 to 2020. Eleven bacterial isolates with morphology similar to R. andropogonis were obtained from the diseased bougainvillea leaves. The isolates were confirmed as R. andropogonis by phenotypic tests and 16S rRNA, rpoD and gyrB gene sequencing. In addition to bougainvillea, the strains were pathogenic to multiple agriculturally significant crops, including maize (Zea mays), sorghum (Sorghum bicolor), barley (Hordeum vulgare), coffee (Coffea arabiga), carnation (Dianthus caryophilus), Mexican lime (Citrus x aurantifolia), common bean (Phaseolus vulgaris), broadbeans (Vicia faba) and pea (Pisum sativum), but not runner bean (Phaseolus coccineus). The presence of this bacterium represents a challenge for plant protection strategies in Mexico.

Comparison of Different Phenotypic Tests versus PCR in the Detection of Carbapenemase-Producing Pseudomonas aeruginosa Isolates in Hamadan, Iran

In recent years, the prevalence of carbapenem-resistant Pseudomonas aeruginosa isolates has become a worldwide concern. Rapid and accurate detection of carbapenemase-producing P. aeruginosa isolates is so important. The aim of this study was to evaluate the performance of the phenotypic methods such as Modified Hodge test (MHT), CarbaNP (CNPt), combined double-disk synergy test (CDDT), and carbapenem inactivation method (CIM) for rapid and accurate detection of clinical carbapenemase production of P. aeruginosa isolates. This study was performed on 97 P. aeruginosa strains, which were isolated from clinical samples in Hamadan hospitals, western Iran in 2017-2018. Antibiotic susceptibility testing was performed using disk diffusion and minimum inhibitory concentration (MIC) by E-test method. We evaluated the performance of MHT, CarbaNP, CDDT, and CIM tests in comparison to polymerase chain reaction (PCR) for the detection of carbapenemase-producing isolates. Additionally, the presence of carbapenem-resistant genes was investigated using the PCR method. Our findings showed that the highest resistance was to cefoxitin (94.8%). Moreover, among the carbapenem antibiotics, the highest resistance was to imipenem (49.4%). Among the 49 carbapenem-resistant isolates, 42 (85.7%) isolates were MIC positive. The results of phenotypic tests showed that CarbaNP, CIM, CDDT, and MHT tests were positive in (48/49, 97.95%), (46/49, 93.87%), (27/49, 57.44%), and (25/49, 53.19%) of isolates, respectively. CarbaNP and CIM tests showed high sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) compared to PCR in P. aeruginosa isolates. CarbaNP and CIM tests are highly sensitive and specific tests for identifying carbapenemase-producing P. aeruginosa isolates.

Identification and Antimicrobial Resistance of Dermatophilus congolensis from Cattle in Saint Kitts and Nevis

Dermatophilosis is a form of dermatitis caused by the bacterium Dermatophilus congolensis. The disease usually presents as localized purulent dermatitis, crusty hair masses or widespread matting of the hair. This condition is most common in domestic ruminants; but it can also affect other wild animals and humans. Antimicrobial therapy is used in many regions to treat clinical dermatophilosis with varying results. In this study, we aimed to assess the antimicrobial susceptibility of D. congolensis isolates. Fifty-two isolates were obtained from animals showing clinical signs of the disease at farms in St. Kitts. The isolates were then confirmed as D. congolensis by phenotypic tests, PCR and MALDI-TOF Mass Spectrometry. Furthermore, minimum inhibitory concentrations (MIC) of 16 antimicrobial agents were determined, using the broth microdilution method. Although most antimicrobials showed MICs in line with published values, the tetracycline results displayed a clear bimodal distribution over the tested range, with most isolates showing low MICs and 6 isolates much higher values (+/− 100-fold increase). These results indicate the presence of acquired tetracycline resistance in D. congolensis on the island of St. Kitts. Whether the current observation has implications for efficacy of treating the disease must be confirmed in further research.

Extended-Spectrum Β-Lactamases in E. coli Isolates From Hospitalized Patients: A Single-Center Snapshot From Croatia

Background: A significant increasing trend in the prevalence of Escherichia coli strains that produce extended-spectrum β-lactamases (ESBLs) has been observed in recent years, both in the community setting and in the healthcare arena. We aimed to provide a snapshot of the current situation with E. coli β-lactamase–producing strains in a single general hospital by appraising their β-lactamase content and plasmid types, which will inform further clinical and research efforts. Methods: Our study population consisted of all hospitalized patients in different clinical units of the General Hospital in Slavonski Brod during a 1-year period: internal medicine, infectious disease, surgery, urology and ICU. Phenotypic tests for the detection of ESBLs and plasmid-mediated AmpC β-lactamases were initially pursued, followed by the molecular detection (polymerase chain reaction, PCR) of resistance genes using primers for blaTEM, blaCTX-M, and blaSHV. PCR-based replicon typing (PBRT) was conducted to type resistance plasmids carrying ESBL genes. Results: During the study period, 30 E. coli isolates with reduced susceptibility to third-generation cephalosporins (ie, ceftazidime, cefotaxime, and ceftriaxone) were detected in hospitalized patients. These isolates stemmed from blood culture (66.7%), wound swabs (13.3%), urine (13.3%), and drainage content (6.7%). Alongside complete resistance to β-lactam antimicrobial agents, they were also characterized by high resistance to gentamicin (93.3%) and ciprofloxacin (96.7%), whereas 23.3% of isolates were also resistant to ertapenem. Most isolates harbored both blaCTX-M and blaTEM genes concurrently (46.7%), while solitary blaTEM and blaCTX-M genes were found in 33.3% and 20% of these isolates, respectively. The presence of SHV β-lactamases was not found in any of the isolates. PBRT revealed a wide array of diverse plasmid groups, with most of the isolates harboring different combinations; however, 80% of isolates were characterized by plasmid incompatibility group B/O (IncB/O). Conclusions: We detected increased frequency of both TEM and CTX-M type β-lactamases in E. coli isolates from a single-hospital setting, with significant consequences for further treatment approaches. The high prevalence of broad- and extended-spectrum β-lactamase producers tends to prompt an increased carbapenem use (potentially resulting in increased resistance to carbapenems); thus, this type of analytical work should become a standard approach (where possible) in hospital centers in our country and worldwide.Funding: NoDisclosures: None

Cohnella terricola sp. nov., isolated from soil

A Gram-positive, aerobic, flagellated, endospore-forming, rod-shaped strain, designated as G13T, was isolated from soil. The results of 16S rRNA gene sequence analysis led to the conclusion that strain G13T was phylogenetically related to Cohnella boryungensis BR29T (97.5 %) and Cohnella phaseoli CECT 7287T (96.9 %) with digital DNA–DNA hybridization values of 21.0 and 21.4 %, and distantly related to Cohnella thermotolerans CCUG 47242T (94.8 %), type species of the genus Cohnella , at 19.0 %. The genome size of strain G13T was 5 387 258 bp, with 51.3 mol% G+C content. The predominant fatty acids were summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl), anteiso-C17 : 0, iso-C17 : 0 and iso-C15 : 0. The predominant quinone was menaquinone-7 and the major polar lipids were diphosphatidyglycerol, phosphatidylethanolamine, phosphatidylglycerol, lysylphosphatidylglycerol, three aminophospholipids, two phosphoglycolipids, three aminolipids and two unidentified lipids. Based on the data from phenotypic tests and the genotypic differences between strain G13T and its close phylogenetic relatives, strain G13T represents a new species belonging to the genus Cohnella , for which the name Cohnella terricola sp. nov. (=KACC 19905T=NBRC 113748T) is proposed.

Molecular Characterization and Survive Abilities of Salmonella Heidelberg Strains of Poultry Origin in Brazil

The aim of the study was to evaluate the genotypic and phenotypic characteristics of 20 strains of S. Heidelberg (SH) isolated from broilers produced in southern Brazil. The similarity and presence of genetic determinants linked to virulence, antimicrobial resistance, biofilm formation, and in silico-predicted metabolic interactions revealed this serovar as a threat to public health. The presence of the ompC, invA, sodC, avrA, lpfA, and agfA genes was detected in 100% of the strains and the luxS gene in 70% of them. None of the strains carries the blaSHV, mcr-1, qnrA, qnrB, and qnrS genes. All strains showed a multidrug-resistant profile to at least three non-β-lactam drugs, which include colistin, sulfamethoxazole, and tetracycline. Resistance to penicillin, ceftriaxone (90%), meropenem (25%), and cefoxitin (25%) were associated with the presence of blaCTX–M and blaCMY–2 genes. Biofilm formation reached a mature stage at 25 and 37°C, especially with chicken juice (CJ) addition. The sodium hypochlorite 1% was the least efficient in controlling the sessile cells. Genomic analysis of two strains identified more than 100 virulence genes and the presence of resistance to 24 classes of antibiotics correlated to phenotypic tests. Protein-protein interaction (PPI) prediction shows two metabolic pathways correlation with biofilm formation. Virulence, resistance, and biofilm determinants must be constant monitoring in SH, due to the possibility of occurring infections extremely difficult to cure and due risk of the maintenance of the bacterium in production environments.