Folia Microbiologica

Avila-Calderón, Eric Daniel; Flores-Romo, Leopoldo; Sharon, Witonsky; Donis-Maturano, Luis; Becerril-García, Miguel Angel; Arreola, Ma. Guadalupe Aguilera; Reynoso, Beatriz Arellano; Güemes, Francisco Suarez; Contreras-Rodríguez, Araceli

doi: 10.1007/s12223-019-00691-6pmid: 30783994

As dendritic cells (DCs) are among the first cells to encounter antigens, these cells trigger both innate and T cell responses, and are the most potent antigen-presenting cells. Brucella spp., which is an intracellular facultative and stealthy pathogen, is able to evade the bactericidal activities of professional phagocytes. Several studies have demonstrated that Brucella can survive and replicate intracellularly, thereby provoking impaired maturation of DCs. Therefore, the interaction between DCs and Brucella becomes an interesting model to study the immune response. In this review, we first will describe the most common techniques for DCs differentiation in vitro as well as general features of brucellosis. Then, the interaction of DCs and Brucella, including pathogen recognition, molecular mechanisms of bacterial pathogenesis, and intracellular trafficking of Brucella to subvert innate response, will be reviewed. Finally, we will debate diversity in immunological DC response and the controversial role of DC activation against Brucella infection.

Kuzma, Jozef; Chmelař, Dittmar; Hájek, Michal; Lochmanová, Alexandra; Čižnár, Ivan; Rozložník, Miroslav; Klugar, Miloslav

doi: 10.1007/s12223-019-00706-2pmid: 31001762

The symbiotic relationship between intestinal microbiota and the host is a major mechanism of prevention against the development of chronic and metabolic diseases. The intestinal microbiota provides several physiological functions of the organism from the creation of a natural functional barrier with a subsequent immunostimulatory activity up to affecting the energy metabolism of the host. Disruption of physiological intestinal microbiota is reported as one of the major etiological factors of initiation and progression of colorectal carcinoma (CRC). Chronic low-grade inflammation is associated with the development of CRC, through the production of inflammatory cytokines and reactive oxygen species. CRC occurs in association with high-protein and high-fat diets in combination with low-fiber intake. The problem of intestinal dysbiosis and oncological diseases is a multidisciplinary problem and it is necessary to focus on several fields of medicine such as public health, clinical pharmacology, and internal medicine. The aim of this review is describing the role of gut dysbiosis in pathogenesis of colorectal carcinoma.

Sahoo, Kalpana; Sahoo, Rajesh Kumar; Gaur, Mahendra; Subudhi, Enketeswara

doi: 10.1007/s12223-019-00710-6pmid: 31102141

Enzymes of microbial origin are of immense importance for organic material decomposition leading to bioremediation of organic waste, bioenergy generation, large-scale industrial bioprocesses, etc. The market demand for microbial cellulase enzyme is growing more rapidly which ultimately becomes the driving force towards research on this biocatalyst, widely used in various industrial activities. The use of novel cellulase genes obtained from various thermophiles through metagenomics and genetic engineering as well as following metabolic engineering pathways would be able to enhance the production of thermophilic cellulase at industrial scale. The present review is mainly focused on thermophilic cellulolytic bacteria, discoveries on cellulase gene, genetically modified cellulase, metabolic engineering, and their various industrial applications. A lot of lacunae are yet to overcome for thermophiles such as metagenome analysis, metabolic pathway modification study, search of heterologous hosts in gene expression system, and improved recombinant strain for better cellulase yield as well as value-added product formation.

Behzadi, Payam

doi: 10.1007/s12223-019-00719-xpmid: 31165977

The presence of a diversity of virulence factors such as Chaperone-Usher (CU) fibers in uropathogenic Escherichia coli (UPEC) pathotypes virulome has offered these bacteria a unique opportunity to select the right factors in suitable condition. Understanding the structures and mechanisms of these infectious weapons enables us to prevent the occurrence of infections and/or to treat the urinary tract infections (UTIs) with effective methodologies. This review summarizes the current knowledge on the mechanisms of CU fimbriae (CUF) formation in UPEC. Several CU fibers including Auf, Dr, F1C, S, Type 9, Type 3, Type 1, and P fimbriae have been recognized in UPEC pathotypes. These fimbrial organelles may have cross-talk with each other in the presence of different environmental factors. In other words, the expression or the silence of their genes are associated with a wide range of items comprising environmental factors, genetical factors, physiological factors, etc. Recognition, detection, and identification of virulome and the related characteristics, properties, and mechanisms in UPEC enable us to create new methodologies to have a definite prevention and treatment for UTIs in this regard.

Rashid, Naeem; Aslam, Mehwish

doi: 10.1007/s12223-019-00730-2pmid: 31286382

Almost 25 years have passed since the discovery of a planktonic, heterotrophic, hyperthermophilic archaeon named Thermococcus kodakarensis KOD1, previously known as Pyrococcus sp. KOD1, by Imanaka and coworkers. T. kodakarensis is one of the most studied archaeon in terms of metabolic pathways, available genomic resources, established genetic engineering techniques, reporter constructs, in vitro transcription/translation machinery, and gene expression/gene knockout systems. In addition to all these, ease of growth using various carbon sources makes it a facile archaeal model organism. Here, in this review, an attempt is made to reflect what we have learnt from this hyperthermophilic archaeon.

Lauková, Andrea; Kandričáková, Anna; Bino, Eva; Tomáška, Martin; Kološta, Miroslav; Kmeť, Vladimír; Strompfová, Viola

doi: 10.1007/s12223-019-00703-5pmid: 31041600

In Slovakia, dairy products made from ewes’ milk have a long tradition. These products include the lactic acid product called “žinčica” which is a by-product occurring during the preparation of ewes’ lump cheese. There is no information in the literature regarding the special properties of the microbiota, especially lactic acid Firmicutes, which can survive in “žinčica.” From the safety aspect, enterococci are a controversial group of bacteria, and those from “žinčica” have never been tested for their properties. The “žinčica” used in our study was supplied by several different agrofarms producing ewes’ lump cheese in central Slovakia. The species Enterococcus faecium (strains EF30E1, EF32E1, EF34E1, EF34E5) and Enterococcus faecalis (strains EE30E4, EE35E1, E31E2, altogether 7) were detected in samples from “žinčica” identified using MALDI-TOF spectrometry with secure genus identification/probable species identification and then confirmed by means of PCR. Enterococci were hemolysis-negative and the genes of the typical enterococcal virulence factors were mostly absent; the gelE gene was found in two E. faecium strains (EF30E1 and EF32E1), the agg gene was detected in E. faecalis EE35E1, and the esp gene was found in two E. faecalis strains (EE30E4 and EE31E2). No strains harbored the cytolysin A gene. Biofilm formation was detected in four strains (EF30E1, EF32E1, EF34E1, and EF34E5), indicating highly positive and low-grade positive biofilm formation. Enterococci were mostly susceptible to antibiotics tested for their phenotype. This is the first study to analyze enterococci in “žinčica.”

Aguilar-Santelises, M.; Castillo-Vera, J.; Gonzalez-Molina, R.; Garcia del Valle, A.; Cruz Millan, M.; Aguilar-Santelises, L.

doi: 10.1007/s12223-019-00707-1pmid: 31001763

Antibiotic-resistant Escherichia coli are common causative agents of human urinary tract infections. Organotin compounds (OTCs) are man-made chemicals that may affect the renal function of exposed humans and rodents. OTCs are widely recognized as bactericides. However, many environmental and a few clinically relevant bacteria have been found resistant to high concentrations of some OTCs. We examined the susceptibility from 47 E. coli clinical isolates to 12 antibiotics and 5 OTCs. Minimum inhibitory concentrations were determined by the fully automated Sensititre™ ARIS™ 2X system, and E. coli strains were classified as resistant, intermediate resistant, or sensitive, according to the M07-A10 and M100-S26 criteria from the National Committee for Clinical Laboratory Standards. All 47 E. coli strains were susceptible to amikacin but resistant to imipenem and intermediate resistant to ampicillin, cefuroxime, and chloramphenicol. In addition, 26 strains were resistant and 21 intermediate resistant to aztreonam, 24 strains were resistant and 23 intermediate resistant to ceftazidime, 44 strains were intermediate resistant and 3 sensitive to cephalothin, and 43 strains were intermediate resistant and 4 sensitive to ciprofloxacin. Approximately half of the strains were susceptible to cefepime, cefotaxime, and gentamicin. E. coli strains were also found resistant to triphenyltin, tributyltin, dibutyltin, trimethyltin, or dimethyltin at final concentration between 10 μmol/L and 1 mmol/L, during 72-h in vitro culture. However, higher in vitro growth inhibition was induced by these OTCs in the presence of the efflux pump inhibitor carbonyl cyanide-m-chlorophenyl hydrazone, which suggests that efflux pumps contribute to making antibiotic-resistant E. coli also resistant to OTCs.

Kozlovsky, A. G.; Kochkina, G. A.; Zhelifonova, V. P.; Antipova, Т. V.; Ivanushkina, N. E.; Ozerskaya, S. M.

doi: 10.1007/s12223-019-00708-0pmid: 30982204

From undisturbed Antarctic habitats (permafrost sediments 30–150 thousand years of age, water of Radok Lake) and superficial deposits contaminated with petroleum products, we isolated 14 and 9 strains of Penicillium fungi, respectively. Comparison of the fungal complexes showed them to differ by species composition; only two species—P. palitans and P. solitum—were in the species lists of both groups. The identified secondary metabolites in the investigated strains belonged to diketopiperazine (group of roquefortines, rugulosuvin B), benzodiazepine (anacin, cyclopenins), quinoline alkaloids (viridicatins), clavine ergot alkaloids (α-cyclopiazonic acid, festuclavine, fumigaclavines), polycyclic indole alkaloids (communesin B, chaetoglobosin A), amino acid derivatives (N-acetyltryptamine, chrysogins, penicillin G), polyketides (citreoviridin A, mycophenolic acid), and terpenes (andrastins, phomenone). Strains isolated from anthropogenically altered habitats produced a more complete and characteristic profile of exometabolites, as compared with strains isolated from undisturbed habitats. It is only from contaminated soils there were isolated fungi that produced more structurally diverse secondary metabolites pertaining to polycyclic indole alkaloids and terpenoids. The fungi isolated from contaminated samples can be used in biodegradation of oil spills and bioremediation of the environment, and also as producers of promising biologically active compounds.

Baite, Mathew S.; Upadhyay, Balendu K.; Dubey, Sunil C.

doi: 10.1007/s12223-019-00711-5pmid: 31049801

Ascochyta blight of chickpea is caused by Ascochyta rabiei (Pass.) Labr. which is primarily seedborne. For rapid detection and precise identification of A. rabiei, a sequence-characterized amplified region (SCAR) marker was developed for detection of genomic DNA and infected plant DNA. An SSR primer amplified monomorphic band was cloned in pGEM®-T easy vector and sequenced. The best primer pair was selected and validated on A. rabiei. The specificity and sensitivity of the SCAR-based marker designated as MBAR was evaluated using conventional PCR and real-time PCR. The marker produced consistently an amplicon size of 196 bp in all A. rabiei isolates tested. The sensitivity of the marker was 0.1 ng of genomic fungal DNA and 0.5 ng of plant DNA by conventional PCR and 0.5 pg of A. rabiei DNA and 1.0 pg of plant DNA by real-time PCR. This is the first SCAR marker having high specificity and sensitivity towards A. rabiei. The marker may be useful in detecting the pathogen before the disease appearance and in plant quarantine program to detect the pathogen in seed lots.

Zak, P.; Vejrazkova, E.; Zavrelova, A.; Pliskova, L.; Ryskova, L.; Hubacek, P.; Stepanova, V.; Kostal, M.; Koblizek, V.; Paterova, P.; Radocha, Jakub

doi: 10.1007/s12223-019-00712-4pmid: 31073843