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Research has been conducted on the ATP-dependent Clp protease complex. The physiological role of this complex in Salmonella enterica serovar Typhimurium has been investigated via the construction of the in-frame deletion of clpP gene and the details are reported.

Wild-animals can act as reservoirs for resistant bacteria and transfer of resistance genes in the environment. These genes can spread to livestock and human either directly by transmission of shared resistant bacteria, or by horizontal gene-transfer to environmental bacteria. To ascertain at what extent wild-animals carry resistance genes, eight faecal samples from buffalo, zebra and wildebeest from Ngorongoro Conservation Area (NCA) and Mikumi National Park (MNP), and four control samples from local zebu cattle grazing together with wildlife in NCA. The qPCR was carried on 14 antimicrobial resistance genes including tetracycline (tet(A), tet(B), 93 tet(C), tet(M), tet(O), tet(W), macrolide, lincosamide, streptogramin B (ermB, ermF), sulphonamide (sulI, sulII), beta-lactam (blaCTX-M-1 group, blaCMY-2, blaSHV) and glycopeptide (vanA). Samples from NCA, both wildlife and cattle were positive for 8 out of 14 resistance genes. The most prevalent genes were tet(W) and blaCMY-2 with the latter being of concern in encoding ESBL-type resistance. Three samples from Buffalo not interacting with cattle in MNP, were positive for tet(W) and blaCMY-2, and in addition for sulI. This suggests that wild ungulates on savannah, irrespective of contact with cattle, may constitute a reservoir for antimicrobial resistance determinants. Further studies are indicated to determine resistance gene-pool among wildlife animals. [ABSTRACT FROM AUTHOR]

Aims: To analyse and compare the effect of selection power for antimicrobial resistance (AMR) in coliforms of two kinds of β-lactams--aminopenicillins; ampicillin (Amp) and cephalosporins; cephalexin (Cpn) and ceftiofur (Cef)-- and tetracycline (Tet) using an approach based on a swine faecal microcosmos. Methods and Results: Sixteen faecal samples from 32 pigs (mixed two by two) were treated with Amp, Cpn, Cef and Tet for 6 h (T6h) at concentrations expected to reach the animals gut when using in vivo standard doses. Controls (no drug added) were also tested. Next, samples were 1 : 100 diluted and left under the same conditions (no antimicrobial added) for further 20 h (T20h). The proportion of resistant coliform bacteria (R coliforms) to each antimicrobial was analysed just before starting the treatment (T0), at T6h and at T20h. Coselection was also studied by replica plating. Treatment for 6 h yielded significant increase in proportion of R coliforms, regardless of the drug and lack of selection pressure showed different effects at T20h depending on the antimicrobial used. Selective pressure was associated with the type of the b-lactam with Amp selecting for significantly higher numbers of R coliforms than cephalosporins. Conclusions: AMR development was observed following short treatment, and for Amp and Tet treatment, resistance persisted 20 h beyond the interruption of treatment. An association between kind of b-lactam and power of selection was found. Significance and Impact of the Study: AMR represents a threat to human health globally and antimicrobial treatment of livestock has a direct impact on this problem. Through our approach based on a swine faecal microcosmos, we demonstrated the effect on AMR development of several drugs commonly used in livestock. Cephalosporins, representing last-line antimicrobials in human medicine, exerted lower selective pressure than Amp under the conditions used and yielded higher proportion of multidrug-R strains. [ABSTRACT FROM AUTHOR]

Presents information on a study which devised a modified internal reflection technique to permit the infrared spectroscopy of thin films of SiO[sub2] on silicon by eliminating the silicon substrate absorption and providing an optical amplification of three orders of magnitude. Experimental arrangement; Review of the theory of internal reflection; Evaluation of the effects of different oxide structures on the infrared spectra; Identification of the local bond configuration.

Abstract: Aim: The study aimed to isolate and characterize Enterococcus species from apparently healthy waste attendants, cattle and cattle waste in Tanzania. Emphasis was given to antimicrobial resistance and in particular occurrence of vancomycin (VA)‐resistant enterococci. Methods and Results: Faecal samples were collected from healthy cattle, cattle waste attendants and cattle house wastes, and isolation of Enterococcus species was performed using Slanetz Bartley agar. Isolates were characterized with regard to species, antimicrobial susceptibility and presence of VA resistance genes. Enterococcus faecalis was the most prevalent species from all sources of isolation (43·5%), followed by Enterococcus faecium (38·4%). Isolates of E. faecium showed a higher number of phenotypic antimicrobial resistance than isolates of E. faecalis. Fifty‐eight isolates, which showed resistance or intermediate resistance to VA by disc diffusion test, were analysed for VA‐resistant Enterococcus (VRE) by PCR. The vanA gene was detected in 14 isolates of E. faecium and 12 isolates of E. faecalis, while vanB was detected in three isolates. No isolates were found to carry vanC1‐gene. Conclusion: VRE was detected in both human and cattle samples, despite no known use of antimicrobial agents that can select for VRE in livestock in Tanzania. Enterococcus faecalis was the most commonly isolated species from cattle and humans. Significance and Impact of the Study: The study provides information on the prevalence of VRE in human and nonhuman samples in Tanzania calling for further studies on the origin of VRE in such isolates, since no selection mechanism in Tanzania are known. [ABSTRACT FROM AUTHOR]