Quinolone Resistance in Non-typhoidal Salmonella

Non‐typhoidal Salmonella is the primary foodborne zoonotic agent of salmonellosis in many countries. Non‐typhoidal Salmonella infections are transmitted to humans primarily through consumption of contaminated foods from animal origin, whereas S. Typhi and Paratyphi infections are spread directly or indirectly by contact with an infected person. Quinolones exhibit potent antibacterial activity against Salmonella and are usually the first choice of treatment for life‐threatening salmonellosis due to multidrug‐resistant strains. However, by the early 1990s, quinolones have been approved for use in food‐producing animals. The increased use of this group of antimicrobials in animal has led to the concomitant emergence of quinolone‐resistant non‐typhoidal Salmonella strains. However, in some countries, there are no legal provisions, which apply to veterinary drugs. This situation provides favorable conditions for spread and persistence of quinolone‐resistant bacteria in food‐producing animals. The objective of this chapter is to review the current regulatory controls for the use of quinolones in food‐producing animals, its effect on development of quinolone resistance, and the potential impact on human and animal health. Moreover, this chapter reviews the current knowledge of quinolone resistance mechanisms and the future directions of research with particular attention to the strategies to control the emergence of quinolone‐resistant Salmonella

Rainbow Kaposi's Sarcoma-Associated Herpesvirus Revealed Heterogenic Replication with Dynamic Gene Expression.

Molecular mechanisms of Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation have been studied primarily by measuring the total or average activity of an infected cell population, which often consists of a mixture of both nonresponding and reactivating cells that in turn contain KSHVs at various stages of replication. Studies on KSHV gene regulation at the individual cell level would allow us to better understand the basis for this heterogeneity, and new preventive measures could be developed based on findings from nonresponding cells exposed to reactivation stimuli. Here, we generated a recombinant reporter virus, which we named "Rainbow-KSHV," that encodes three fluorescence-tagged KSHV proteins (mBFP2-ORF6, mCardinal-ORF52, and mCherry-LANA). Rainbow-KSHV replicated similarly to a prototype reporter-KSHV, KSHVr.219, and wild-type BAC16 virus. Live imaging revealed unsynchronized initiation of reactivation and KSHV replication with diverse kinetics between individual cells. Cell fractionation revealed temporal gene regulation, in which early lytic gene expression was terminated in late protein-expressing cells. Finally, isolation of fluorescence-positive cells from nonresponders increased dynamic ranges of downstream experiments 10-fold. Thus, this study demonstrates a tool to examine heterogenic responses of KSHV reactivation for a deeper understanding of KSHV replication.IMPORTANCE Sensitivity and resolution of molecular analysis are often compromised by the use of techniques that measure the ensemble average of large cell populations. Having a research tool to nondestructively identify the KSHV replication stage in an infected cell would not only allow us to effectively isolate cells of interest from cell populations but also enable more precise sample selection for advanced single-cell analysis. We prepared a recombinant KSHV that can report on its replication stage in host cells by differential fluorescence emission. Consistent with previous host gene expression studies, our experiments reveal the highly heterogenic nature of KSHV replication/gene expression at individual cell levels. The utilization of a newly developed reporter-KSHV and initial characterization of KSHV replication in single cells are presented

Variable Stars in the Magellanic Clouds: Results from OGLE and SIRIUS

We have performed a cross-identification between OGLE-II data and single-epoch SIRIUS JHK survey data in the LMC and SMC. After eliminating obvious spurious variables, we determined the pulsation periods for 9,681 and 2,927 variables in the LMC and SMC, respectively. Based on these homogeneous data, we studied the pulsation properties and metallicity effects on period-K magnitude (PK) relations by comparing the variable stars in the LMC and SMC. The sample analyzed here is much larger, and we found the following new features: (1) variable red giants in the SMC form parallel sequences on the PK plane, just like those found by Wood (2000) in the LMC; (2) both of the sequences A and B of Wood (2000) have discontinuities, and they occur at the K-band luminosity of the TRGB; (3) the sequence B of Wood (2000) separates into three independent sequences B+- and C'; (4) comparison between the theoretical pulsation models (Wood et al. 1996) and observational data suggests that the variable red giants on sequences C and newly discovered C' are pulsating in the fundamental and first overtone mode, respectively; (5) the theory can not explain the pulsation mode of sequences A+- and B+-, and they are unlikely to be the sequences for the first and second overtone pulsators, as was previously suggested; (6) the zero points of PK relations of Cepheids in the metal deficient SMC are fainter than those of LMC ones by ~0.1 mag but those of SMC Miras are brighter than those of LMC ones by ~0.13 mag, which are probably due to metallicity effects.Comment: 9 pages, 10 figures, accepted for publication in MNRAS. High resolution version is available at: http://www.ioa.s.u-tokyo.ac.jp/~yita/scr/astro/papers/RefereedPaper/yitaMD250 .pd

Emerging Infectious Diseases in Water Buffalo: An Economic and Public Health Concern

Water buffalo is an indispensable livestock in Asia and other countries due to its high meat and milk quality, aside from draft power source. It adapts well to tropical climate and has significant contribution to the livestock industry, provided with improved breeding and good animal husbandry practices. Infectious diseases are hindrance to good reproductive performance of livestock, resulting in huge economic loss. In addition, most of these diseases are zoonotic, posing serious threats on human health. However, its degree of severity varies in each region and is often overlooked. This chapter reviews the common and current updates on emerging bacterial, viral, protozoal, fungal and endoparasitic pathogens that infect water buffaloes worldwide. All of the diseases directly affect the animals’ health condition except for schistosomiasis where water buffalo played an important role as shedder of infection to humans. Leptospirosis, brucellosis, Bovine Tb, BVDV and fasciolosis have projected economic impact to water buffalo industry as well as its effect as zoonoses. However, the data seem underquantified since most are neglected diseases and are highly prevalent in developing countries. Further studies are needed particularly in countries where water buffalo is the major livestock than cattle to fully utilize the potential of the animal

The performance of an in-house loop-mediated isothermal amplification for the rapid detection of Mycobacterium tuberculosis in sputum samples in comparison with Xpert MTB/RIF, microscopy and culture

Simple, low-cost and effective diagnostic tests for tuberculosis (TB) are needed especially in TB-high burden settings. The present study evaluated the performance of an in-house loop-mediated isothermal amplification (LAMP) for diagnosing TB by comparing it to Xpert MTB/RIF, microscopy and culture. In Thailand, a total of 204 excess sputum samples volume after the processing of cultures were used for Mycobacterium tuberculosis (MTB) detection by Xpert MTB/RIF and LAMP. Based on culture results as the gold standard, the overall sensitivity of LAMP and Xpert MTB/RIF were 82.1% (126/153; 95% confidential interval [CI]: 75.4-88.98%) and 86.9 % (133/153; 95% CI: 80.5-90.8%) respectively, and the specificity of both tests was 100% (51/51; 95% CI: 93.0-100.0%). In comparison with Xpert MTB/RIF, the sensitivity and specificity of LAMP were 94.7% (126/133; 95% CI: 89.5-97.9%), and 100.0% (73/73; 95% CI: 94.9-100.0%), respectively. The average threshold cycle (Ct) of Xpert MTB/RIF detection for positive and negative LAMP results was statistically different, of 18.4 and 27.0, respectively (p < 0.05). In comparison with the acid-fast staining technique, and analyzing LAMP and Xpert MTB/RIF in smear-negative/ culture-positive specimens, there was an increase of the detection rate by 47.7% (21/44) and 54.6% (24/44). The diagnostic sensitivity and specificity of LAMP appeared to be comparable to those of Xpert MTB/RIF. We claim that this LAMP has potential to provide a sensitive diagnostic test for the rapid TB diagnosis. It allowed a fast detection of MTB before the cultures and it could be used in resource-limited laboratory settings