Enterococcus faecium isolated from healthy dogs for potential use as probiotics

This study aimed to isolate and identify enterococci obtained from fresh faecal swabs of 16 healthy dogs. Following molecular identification, all isolates were screened against the most critical virulence factors as well as enterocin (bacteriocin) determinants to confirm that the isolated enterococcus was safe to be used as host-specific probiotic. Enterococcus faecium was isolated and confirmed in 8 out of the 16 samples. Regarding the assessment of the virulence determinants, E. faecium strains were negative for tested (gelE and esp) virulence genes. Furthermore, the genome was evaluated for the incidence of five known enterocin genes by specific PCR amplification. Four strains encoding entAS-48 gene were found, while only one strain harboured the entL50A/B gene. Based on these results, five of the E. faecium isolated in this study were considered as promising probiotic candidates for dogs.

Enhanced antibacterial activity of capped zinc oxide nanoparticles: A step towards the control of clinical bovine mastitis

BACKGROUND AND AIM

Bovine mastitis is the costliest prevalent disease in the dairy sector due to the limitations of conventional treatments. Zinc oxide nanoparticles (ZnO-NPs) have been regarded as safe and economical antibacterial candidates against several microorganisms, but the tendency of these particles to aggregate is a major barrier to their application. This study aimed to enhance the antibacterial efficiency of ZnO-NPs against some bacterial agents, causing bovine mastitis.

MATERIALS AND METHODS

A total of 24 milk samples out of 300 cases from Nubaria farm, Beheira Governorate, Egypt, were collected from cows with clinical mastitis. ZnO-NPs were fabricated by a sonochemical method using starch as a capping agent and by an auto-combustion reaction using glycine as a fuel. The two preparations of synthesized ZnO-NPs at different concentrations were assessed for their antimicrobial activities in vitro against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae isolated from milk of affected cows.

RESULTS

Sonochemically synthesized capped ZnO-NPs were dispersed and non-agglomerated in comparison with aggregated uncapped ZnO-NPs prepared by an auto-combustion reaction. Capped dispersed ZnO-NPs showed higher antibacterial activity against S. aureus, E. coli, and K. pneumoniae than particles synthesized by the auto-combustion reaction at same concentrations. However, the zone of inhibition for dispersed and agglomerated ZnO-NPs was concentration-dependent. In addition, Gram-positive S. aureus exhibited higher resistance to ZnO-NPs synthesized by both methods than Gram-negative E. coli and K. pneumoniae.

CONCLUSION

Dispersed, non-agglomerated ZnO-NPs fabricated using starch as a capping agent under sonochemical irradiation could potentially be regarded as highly effective and inexpensive antimicrobial agents against S. aureus, E. coli, and K. pneumoniae for the management of bovine mastitis.

Structuring Diabetes Mellitus Care in Long-Term Nursing Home Residents

Nursing home residents with diabetes have more complex care needs with higher levels of comorbidity, disability and cognitive impairment. We compared current practice in the 44 long-term residents in Peamount hospital with the standards recommended in the Diabetes UK "Good Clinical Practice Guidelines for Care Home Residents with Diabetes". Of 44 residents, 11 were diabetic. Residents did not have specific diabetes care plans. There were some elements of good practice with a low incidence of hypoglycaemia and in-house access to dietetics and chiropody. However, diabetes care was delivered on an ad-hoc basis without individualised care plans, documented glycaemic targets, or scheduled monitoring for complications and no formal screening for diabetes on admission. National and local policy to guide management of diabetes mellitus should be developed. There should be individualised diabetes care plans, clear policies for hypoglycaemia, hyperglycaemia and long-term diabetes complications, screening on admission and increased uptake of the national retinal screening and foot care programmes.

Tetracycline resistance phenotypes and genotypes of coagulase-negative staphylococcal isolates from bubaline mastitis in Egypt

Aim::

This study was devoted to elucidate the tetracycline resistance of coagulase-negative staphylococci (CNS) derived from normal and subclinical mastitic (SCM) buffaloes’ milk in Egypt.

Materials and Methods: ::

A total of 81 milk samples from 46 normal buffalo milk samples and 35 SCM buffalo milk samples at private dairy farms of Egypt were used in this study. CNS were identified using phenotypic and molecular methods (polymerase chain reaction [PCR]). CNS isolates were tested for tetracycline resistance using routine methods and multiplex PCR targeting tetracycline (tet) resistance genes followed by sequencing of positive PCR products and phylogenetic analysis.

Results::

Isolation and identification of 28 (34.5%) CNS from normal and SCM buffaloes’ milk, namely, Staphylococcus intermedius (39.2%), Staphylococcus xylosus (25.0%), Staphylococcus epidermidis (10.7%), Staphylococcus hominis (10.7%), and 3.5% to each of Staphylococcus sciuri, Staphylococcus hyicus, Staphylococcus lugdunensis, and Staphylococcus simulans. Using nested PCR, all the 28 CNS isolates revealed positive for 16srRNA gene specific for genus staphylococci and negative for thermonuclease (nuc) gene specific for Staphylococcus aureus species. The presence of tetracycline resistance-encoding genes (tetK, tetL, tetM, and tetO) was detected by multiplex PCR. All isolates were negative for tetL, M, and O genes while 14 (50%) CNS isolates were positive for tetK gene, namely, S. lugdunensis (100%), S. hominis (100%), S. epidermidis (66.6%), S. intermedius (45.4%), and S. xylosus (42.8%). Nucleotide sequencing of tetK gene followed by phylogenetic analysis showed the high homology between our CNS isolates genes of tetracycline resistance with S. aureus isolates including Egyptian ones. This proves the transfer of the tetracycline resistance encoding genes between coagulase-negative and coagulase positive Staphylococcus spp.

Conclusion::

CNS isolates have distinguishingly high resistance to tetracycline. Abundant tetracycline usage for mastitis treatment leads to the spread of genetic resistance mechanisms inside CNS strains and among all Staphylococcus spp. Consequently, tetracycline is not effective anymore.

Synthesis of chitotetraose and chitohexaose based on dimethylmaleoyl protection

tert-Butyldimethylsilyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranoside was readily transformed into the disaccharide glycosyl donor, 3,4,6-tri-O-acetyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-alpha/beta-D-glucopyranosyl trichloroacetimidate, and the disaccharide glycosyl acceptor, tert-butyldimethylsilyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranoside. A TMSOTf-catalysed coupling of the acceptor with the donor afforded the respective tetrasaccharide derivative, which can be transformed to chitotetraose. tert-Butyldimethylsilyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-4-O-phenoxyacetyl-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranoside was converted into donor 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-4-O-phenoxyacetyl-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranosyl trichloroacetimidate. Its coupling with benzyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranoside, followed by dephenoxyacetylation, gave benzyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta-D-glucopyranoside, whose glycosylation furnished, after replacement of the DMM-group by the acetyl moiety and subsequent deprotection, chitohexaose.

Effects of preparation conditions on the monodispersity of albumin microspheres

Monodisperse albumin microspheres were successfully prepared by both chemical or thermal hardening methods via membrane emulsification using microporous glass membranes with uniform pore sizes. The monodispersity of the microspheres was found to depend strongly on parameters such as albumin concentration, emulsifier concentration, and volume ratio of the internal aqueous phase (albumin solution) to the dispersion medium (organic solvent). The optimum conditions for obtaining monodisperse albumin microspheres are described.

Sugarhydrazones of 2-hydrazinoquinolines and their antimicrobial activity

Sugar hydrazones from 2-hydrazinoquinoline, 2-hydrazino-6-methyllepidine, 6-chloro-2-hydrazino lepidine, 7-chloro-2-hydrazinolepidine, and 7-chloro-2-hydrazino-3-nitroquinoline were prepared. Their acetylation, benzoylation, periodate oxidation, oxidation with lead tetraacetate and bromination have been investigated. The antimicrobial activities of the hydrazones were evaluated. Some compounds showed moderate activity.

Steroidal thiourea and thiazoline derivatives: synthesis and in vitro effects on bovine pancreatic ribonuclease activity

Two novel series of steroidal derivatives containing various thiourea and substituted thiazoline moieties attached to the 2- or 4-position of estrone were synthesized and examined for in vitro effect on bovine pancreatic ribonuclease activity. All compounds studied exhibited a catabolic activity. The steroidal thiazoline derivatives were more potent activators of ribonuclease than the steroidal thioureas.

Novel potential anticancer agents derived from benzimidazole

Two novel series of benzimidazole derivatives bearing structural modifications of certain drugs were prepared for evaluation for potential anticancer activity. The first series was a group of alkylating agents, and the second series was a variety of 4-substituted-1-thioacetyl-3-thiosemicarbazides. The tests of some representative products for antileukemic activity against P-388 lymphocytic leukemia indicated no significant effects.

Synthesis of novel hexestrol and diethylstilbestrol derivatives as potential anticancer and estrogenic agents

Two novel series of potential anticancer agents derived from hexestrol and diethylstilbestrol have been synthesized. The first includes several alkylating agents containing sulphonic esters and nitrogen mustard functions attached through various chains to only one phenolic group in hexestrol. The second contains the N1-acetyl-N4-substituted thiosemicarbazide moieties attached to one phenolic group hexestrol or to the two phenolic oxygens in diethylstilbestrol. The tests of some of the products for antileukemic activity in P 388 Lymphocytic Leukemia indicated no significant activity over the parent nuclei. The estrogenic activity of some representative examples of the thiosemicarbazides was found to be dependent on the nature of the N4-substituent in the thiosemicarbazide moiety.

Synthesis of 4-substituted aminobenzoate quaternary salts as potent antispasmodic agents

N-(Diethylaminoethyl)-4-substituted aminobenzoate quaternary salts, N-(diethylaminoethyl)-4-substituted aminobenzamide quaternary salts, 4-substituted acylaminobenzamide quaternary salts, and 4-substituted acylaminosalicylamide derivatives were prepared and tested for antispasmodic activity. Preliminary pharmacological tests on isolated guinea pig ileum revealed that the new compounds possess nonspecific inhibitory action on smooth muscles.

Synthesis of some dibenzazepines of possible therapeutic interest

Among the hypotensive drugs are the N-alkyldibenz[c,e]-azepines. A representative of this class is 6-allyl-6,7-dihydro-5H-dibenz[c,e]azepine (azapetine). The present investigation involved the preparation of a new series of N-[6,7-dihydro-5H-dibenz[c,e]azepin-6-yl] acid amides namely; acetamide, benzamide, phehyl acetamide, salicylamide and p-hydroxybenzamide derivatives. Another new series of N-[6,7-dihydro-5H-dibenz[c,e]azepin-6-yl]-N-alkyl (or aryl) thioureas was prepared namely ethyl, isopropyl, butyl, cyclohexyl, benzyl, phenyl and o-tolyl thiourea derivatives. IR spectra of the two series of compounds were investigated.

Synthesis of some quinoline derivatives of potential antiamebic activity

New compounds derived from cinchoninic acid esters and amides were prepared. The esters are those derived from p-hydroxy-N-methyldichloroacetanilide (diloxanide) whereas the amides are from piperazine whose hydrogen is substituted by a dichloroacetyl group. The dichloroacetamido group is responsible for the amebicidal activity in several related compounds.