The bacterial genus Bartonella is distributed worldwide and poses a public health risk. Cat-scratch disease caused by B. henselae in Croatia was first described in 1957. It is present throughout the ...country: a survey of serum samples from 268 Croatian patients with lymphadenopathy showed that 37.7% had IgG antibodies. Despite this prevalence, we are unaware of reports of Bartonella culturing from infected humans or cats in Croatia or elsewhere in southeast Europe.
Here we describe the diagnosis of a 12-year-old child with lymphadenopathy in Croatia with cat-scratch disease based on antibody detection and clinical signs, and the subsequent culturing and genotyping of B.henselae from the cat's blood. The B. henselae isolate was grown on different blood agar plates and its identity was confirmed based on polymerase chain reaction (PCR) amplification of 16S ribosomal deoxyribonucleic acid (16S rDNA) and sequencing. Multi-locus sequence typing (MLST) identified the strain genotype as sequence type 5, commonly found zoonotic B. henselae strain in cats. The child recovered after azithromycin therapy, and B. henselae in the cat was eliminated within three months after doxycycline treatment.
This is, to our knowledge, the first report of B. henselae culturing and MLST-based genotyping from cat's blood in southeast Europe. Our ability to detect B. henselae in blood through culturing but not PCR suggests that the prevalence of infected cats with low bacteremia is very high, suggesting the need to develop faster, more sensitive detection assays.
Cats are the primary reservoirs of the bacterium Bartonella henselae, the main cause of cat-scratch disease in humans. The main vector of the bacterium is the cat flea, Ctenocephalides felis. In ...southeastern Europe, data are lacking on the prevalence of B. henselae infection in cats, the strains of B. henselae involved and the risk factors associated with the infection.
Blood samples collected in ethylenediaminetetraacetic acid-containing tubes from 189 domestic cats (156 pet cats and 33 stray cats) from Zagreb, the capital city of Croatia, and 10 counties throughout Croatia were cultured for Bartonella spp. Following culture, bacterial isolates were genotyped at eight loci after using PCR to amplify 16S ribosomal RNA (rRNA) and the internal transcribed spacer region between the 16S and 23S rRNA sequences. Univariate and multivariate logistic regression were used to identify risk factors for B. henselae infection in cats.
Bartonella spp. was detected in 31 cats (16.4%), and subsequent genotyping at the eight loci revealed B. henselae in all cases. Thirty complete multilocus sequence typing profiles were obtained, and the strains were identified as four sequence types that had been previously reported, namely ST5 (56.7%), ST6 (23.3%), ST1 (13.3%) and ST24 (3.3%), as well as a novel sequence type, ST33 (3.3%). The univariate analysis revealed a significantly higher risk of B. henselae infection in cats residing in coastal areas of Croatia (odds ratio OR 2.592, 95% confidence interval CI 1.150-5.838; P = 0.0191) and in cats with intestinal parasites (OR 3.207, 95% CI 1.088-9.457; P = 0.0279); a significantly lower risk was identified in cats aged > 1 year (OR 0.356, 95% CI 0.161-0.787; P = 0.0247) and in cats sampled between April and September (OR 0.325, 95% CI 0.147-0.715; P = 0.005). The multivariate analysis that controlled for age showed a positive association with the presence of intestinal parasites (OR 4.241, 95% CI 1.243-14.470; P = 0.0119) and coastal residence (OR 2.567, 95% CI 1.114-5.915; P = 0.0216) implying increased risk of infection, and a negative association with sampling between April and September (OR 0.379, 95% CI 0.169-0.848; P = 0.018) implying a decreased risk of infection. After controlling for the season, an increased risk of infection remained for the coastal region (OR 2.725, 95% CI 1.200-6.186; P = 0.012).
Bartonella henselae is prevalent throughout Croatia and is a public health threat. Environmental and host factors can significantly affect the risk of infection, and these should be explored in more detail. The presence of intestinal parasites highlights the need to eliminate the flea vector, Ctenocephalides felis, as the most effective approach to control infections in cats and humans.
In a recent lambing season (2012/2013), the seroprevalence of ovine chlamydiosis was monitored in small ruminant abortion cases in Croatia. Blood samples of 93 sheep and 69 goats were examined. In ...addition, 50 sheep and 61 goat samples were tested using molecular methods. Furthermore, 14 sheep blood samples, one goat blood sample and one sheep placenta sample from Bosnia and Herzegovina (BIH) were also tested as a part of inter-laboratory cooperation. Overall high seroprevalence was detected in sheep, 19.6% with the ELISA IDEXX kit and 20.5% with the ClVTEST kit. Seroprevalence in goats was 11.4%. In BIH, four sheep and one goat blood sample were seropositive for chlamydiosis. The disease causing agent, Chlamydia abortus (C. abortus) was confirmed using molecular methods in two sheep flocks in continental Croatia and in one sheep flock in BIH. In this study, C. abortus infection in sheep was identified for the first time in Croatia using species specific molecular methods. Ovine chlamydiosis is present in national sheep and goat flocks in Croatia and BIH. Thus should be subject to ongoing controls in the case of abortion. A combination of serological and molecular methods should be used for optimal laboratory diagnostics of C. abortus.
Maleus je kontagiozna bolest konja, magaraca i njihovih križanaca, a mogu oboljeti i mesojedi, uključujući i čovjeka. Obično je kronična, a očituje se tvorbom specifičnih čvorića u koži, potkožju, ...plućima i drugdje u organizmu. U Hrvatskoj je bolest zadnji puta zabilježena 1961. godine.
U Arhivi sojeva Laboratorija za bakterijske zoonoze, Hrvatskog veterinarskog instituta pronađen je liofilizat oznake B. mallei - Karlovac (5.2.1957.). Zbog iznimno rijetkog uzorka namjera je bila ponovno kultivirati soj te ga identificirati daljnjim standardnim i molekularnim testovima potvrditi radi li se zaista o vrsti Burkholderia (B.) mallei. Liofilizirani izolat B. mallei nismo uspjeli kultivirati opisanim bakteriološkim postupcima. Izvršili smo izolaciju DNK iz uzorka otopljenog liofilizata. Koncentracija izolirane DNK izmjerena je na DS-11 spektrofotometru (DeNovix, SAD). Umnožavanjem za vrstu B. mallei specifičnog fliP-IS407A odsječka veličine 989-bp za soj „B.mallei Karlovac 5.2.1957.“ 221. utvrđeno je da se radi o vrsti B. mallei. Prema trenutno dostupnim podatcima molekularne genotipizacije primjenom high resolution melting PCR metode na 15 filogenetski značajnih polimorfizama jedne baze vrste B. mallei, hrvatski soj izdvojen 1957. godine nalazi se u grupi filogenetski srodnih sojeva iz Italije, Mađarske, Turske i Irana iz istog vremenskog razdoblja. Maleus je klasična, reemergentna bakterijska zoonoza i bolest koja ne poznaje granice kako po klinički nespecifičnoj slici i kroničnim oblicima bolesti bez vidljivih simptoma tako i po činjenici da se slučajevi bolesti u konja dijagnosticiraju i danas u zemljama s višegodišnjim statusom bez bolesti. Kontrola konja u međunarodnom prometu je i dalje neophodna.
Halohydrin dehalogenase HheC has been studied in the presence of DMSO, the most commonly used co‐solvent. A combination of experimental and computational methods was applied to elucidate the ...behaviour of this homotetrameric enzyme with a focus on its interactions with DMSO molecules. Further details can be found in the Research Article by Z. Brkljača, M. Majerić Elenkov, and co‐workers (DOI: 10.1002/chem.202201923).
Green roof systems have become an important part in creating sustainable cities. They can provide a wide range of economic, environmental, and social benefits. The goal of this research was to ...quantify the thermal performance improvements from a green roof with mineral wool substrate installed on a school building in a humid subtropical climate. In-situ measurements during a summer period included heat fluxes through the green and reference roof, vertical temperature profile through both roofs, the local air temperature above roofs, and local meteorological parameters. Furthermore, the summer thermal performance of green and reference roof and the green roof cooling effect were evaluated concerning meteorological parameters using the Pearson correlation analysis. The results indicate that the green roof layers have improved thermal performance of the roof with respect to reduced conductive heat flow by 57% and delayed heat transfer. The maximum and averaged reference roof to green roof outdoor surface temperature difference was 27.5 °C and 5.5 °C, respectively. It was found that ambient temperature and relative humidity have a dominant role on the thermal performance of the green and reference roof, while solar radiation and ambient temperature present the key meteorological determinants of the green roof cooling effect.
•The summer thermal behavior of lightweight green roof was experimentally investigated.•The influence of meteorological parameters on the green roof cooling effect was explored.•The green roof with mineral wool substrate decreased heat flow through the roof by 57%.•Green roof reduces the temperature amplitude of outdoor roof surface by 83%.
Although the application of organic solvents in biocatalysis is well explored, in‐depth understanding of the interactions of solvent with proteins, in particular oligomeric ones, is still scant. ...Understanding these interactions is essential in tailoring enzymes for industrially relevant catalysis in nonaqueous media. In our study, the homotetrameric enzyme halohydrin dehalogenase (HHDH) from Agrobacterium radiobacter AD1 (HheC) was investigated, as a model system, in DMSO/water solvent mixtures. DMSO, the most commonly used co‐solvent for biocatalytic transformations, was found to act as a mixed‐type inhibitor with a prevalent competitive contribution. Even 5 % (v/v) DMSO inhibits the activity of HheC by half. Molecular dynamics (MD) simulations showed that DMSO keeps close to Ser‐Tyr catalytic residues forming alternate H‐bonds with them. Stability measurements paired with differential scanning calorimetry, dynamic light scattering methods and MD studies revealed that HheC maintains its structural integrity with as much as 30 % (v/v) DMSO.
Pros and cons considered: Halohydrin dehalogenases (HHDHs) are versatile enzymes employed in the synthesis of chiral building blocks. To increase substrate solubility, DMSO stands out as the most commonly used co‐solvent. Here we found that DMSO acts as an inhibitor of the enzyme HheC. To understand the observed phenomena at the molecular level, in‐depth experimental studies were performed in combination with molecular dynamics simulations.
Ten different fluorinated aromatic epoxides have been tested as potential substrates for halohydrin dehalogenase (HHDH) HheC. The majority of investigated epoxides are useful building blocks in ...synthetic chemistry applications, with a number of them being polysubstituted. Moderate to high enantioselectivities (
= 15 → 200) were observed in azidolysis, allowing the synthesis of enantioenriched (
)-azido alcohols containing fluorine in the molecule. In the case where a reaction runs over 50% conversion, enantiopure (
)-epoxides are also available. While
-F-styrene oxide was easily converted into a product, a sterically challenging
-CF
-derivative was not accepted by HheC.
probing of the binding site indicates that, in order to accommodate an
-CF
-derivative in the HheC active site, it is necessary to eliminate steric hindrance. Hence, we extended our research by probing several available HheC variants containing relevant modifications in the active site. The active mutant P84V/F86P/T134A/N176A (named HheC-M4) was identified, showing not only high activity towards
-CF
-styrene oxide, but also inverted enantioselectivity (
= 27). Since (
)-enantioselective HHDHs are rare and therefore valuable for their synthetic application, this enzyme was screened on the initial panel of substrates. The observed (
)-enantioselectivity (
= 1-111) is ascribed to the formation of the additional space by introduced mutations in HheC-M4, which is also confirmed by classical MD simulations. Successive molecular docking demonstrated that this newly formed tunnel located close to the protein surface is a critical feature of HheC-M4, representing a novel binding site.
Sets of 346 herbicides in use and 163 no longer in use were collected from open access online sources and compared in silico with cholinesterases inhibitors (ChI) and drugs in terms of ...physicochemical profile and estimated toxic effects on human health. The screening revealed at least one potential adverse consequence for each herbicide class assigned according to their mode of action on weeds. The classes with most toxic warnings were K1, K3/N, F1 and E. The selection of 11 commercial herbicides for in vitro biological tests on human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the enzymes involved in neurotoxicity and detoxification of various xenobiotics, respectively, was based mainly on the structural similarity with inhibitors of cholinesterases. Organophosphate anilofos and oxyacetanilide flufenacet were the most potent inhibitors of AChE (25 μM) and BChE (6.4 μM), respectively. Glyphosate, oxadiazon, tembotrione and terbuthylazine were poor inhibitors with an estimated IC50 above 100 μM, while for glyphosate the IC50 was above 1 mM. Generally, all of the selected herbicides inhibited with a slight preference towards BChE. Cytotoxicity assays showed that anilofos, bensulide, butamifos, piperophos and oxadiazon were cytotoxic for hepatocytes (HepG2) and neuroblastoma cell line (SH-SY5Y). Time-independent cytotoxicity accompanied with induction of reactive oxygen species indicated rapid cell death in few hours. Our results based on in silico and in vitro analyses give insight into the potential toxic outcome of herbicides in use and can be applied in the design of new molecules with a less impact on humans and the environment.
•Computational analysis of herbicides shows potential for neurotoxicity.•Chemical structure of herbicides affects their modes of action and toxicity.•Organophosphates anilofos, bensulide and piperophos inhibit both cholinesterases.•The inhibition is governed by non-covalent and covalent interactions.•Cytotoxicity toward neuronal and hepatic cells was observed for several herbicides.
Invited for the cover of this issue are Zlatko Brkljača, Maja Majerić Elenkov and co‐workers at the Ruđer Bošković Institute and University of Zagreb. The image depicts the enzyme halohydrin ...dehalogenase HheC, which is made up of four identical subunits, with marked catalytic residues and volumetric maps of water and DMSO in the active site. Read the full text of the article at 10.1002/chem.202201923.
“The first comprehensive study of the mechanisms by which DMSO, the most commonly used co‐solvent in the halohydrin dehalogenase‐catalysed reactions, influences the activity and stability of the enzyme HheC.” This and more about the story behind the front cover can be found in the article at 10.1002/chem.202201923).
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