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result(s) for
"Ghosh, Anuradha"
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Insects in confined swine operations carry a large antibiotic resistant and potentially virulent enterococcal community
2011
Background
Extensive use of antibiotics as growth promoters in the livestock industry constitutes strong selection pressure for evolution and selection of antibiotic resistant bacterial strains. Unfortunately, the microbial ecology and spread of these bacteria in the agricultural, urban, and suburban environments are poorly understood. Insects such as house flies (
Musca domestica
) and German cockroaches (
Blattella germanica
) can move freely between animal waste and food and may play a significant role in the dissemination of antibiotic resistant bacteria within and between animal production farms and from farms to residential settings.
Results
Enterococci from the digestive tract of house flies (
n
= 162), and feces of German cockroaches (
n
= 83) and pigs (
n
= 119), collected from two commercial swine farms were isolated, quantified, identified, and screened for antibiotic resistance and virulence. The majority of samples (93.7%) were positive for enterococci with concentrations 4.2 ± 0.7 × 10
4
CFU/house fly, 5.5 ± 1.1 × 10
6
CFU/g of cockroach feces, and 3.2 ± 0.8 × 10
5
CFU/g of pig feces. Among all the identified isolates (n = 639)
Enterococcus faecalis
was the most common (55.5%), followed by
E. hirae
(24.9%),
E. faecium
(12.8%), and
E. casseliflavus
(6.7%).
E. faecalis
was most prevalent in house flies and cockroaches, and
E. hirae
was most common in pig feces. Our data showed that multi-drug (mainly tetracycline and erythromycin) resistant enterococci were common from all three sources and frequently carried antibiotic resistance genes including
tet
(M) and
erm
(B) and Tn
916
/
1545
transposon family.
E. faecalis
frequently harbored virulence factors
gelE, esp,
and
asa1
. PFGE analysis of selected
E. faecalis
and
E. faecium
isolates demonstrated that cockroaches and house flies shared some of the same enterococcal clones that were detected in the swine manure indicating that insects acquired enterococci from swine manure.
Conclusions
This study shows that house flies and German cockroaches in the confined swine production environment likely serve as vectors and/or reservoirs of antibiotic resistant and potentially virulent enterococci and consequently may play an important role in animal and public health.
Journal Article
Modeling spatiotemporal dynamics of Amblyomma americanum questing activity in the central Great Plains
by
Little, Susan E.
,
Ghosh, Anuradha
,
Xiao, Xiangming
in
Amblyomma - physiology
,
Amblyomma americanum
,
Animals
2024
Ticks represent important vectors of a number of bacterial and viral disease agents, owing to their hematophagous nature and their questing behavior (the process in which they seek new hosts). Questing activity is notably seasonal with spatiotemporal dynamics that needs to be understood in detail as part of mediating and mitigating tick-borne disease risk. Models of the geography of tick questing activity developed to date, however, have ignored the temporal dimensions of that behavior; more fundamentally, they have often not considered the sampling underlying available occurrence data. Here, we have addressed these shortfalls for Amblyomma americanum , the most commonly encountered tick in the central Great Plains, via (1) detailed, longitudinal sampling to characterize the spatiotemporal dimensions of tick questing activity; (2) randomization tests to establish in which environmental dimensions a species is manifesting selective use; and (3) modeling methods that include both presence data and absence data, taking fullest advantage of the information available in the data resource. The outcome was a detailed picture of geographic and temporal variation in suitability for the species through the two-year course of this study. Such models that take full advantage of available information will be crucial in understanding the risk of tick-borne disease into the future.
Journal Article
Phenology of five tick species in the central Great Plains
by
Ghosh, Anuradha
,
Little, Susan
,
Ng’eno, Eric
in
Activity patterns
,
Amblyomma - growth & development
,
Amblyomma - physiology
2024
The states of Kansas and Oklahoma, in the central Great Plains, lie at the western periphery of the geographic distributions of several tick species. As the focus of most research on ticks and tick-borne diseases has been on Lyme disease which commonly occurs in areas to the north and east, the ticks of this region have seen little research attention. Here, we report on the phenology and activity patterns shown by tick species observed at 10 sites across the two states and explore factors associated with abundance of all and life specific individuals of the dominant species. Ticks were collected in 2020–2022 using dragging, flagging and carbon-dioxide trapping techniques, designed to detect questing ticks. The dominant species was A . americanum (24098, 97%) followed by Dermacentor variabilis (370, 2%), D . albipictus (271, 1%), Ixodes scapularis (91, <1%) and A . maculatum (38, <1%). Amblyomma americanum , A . maculatum and D . variabilis were active in Spring and Summer, while D . albipictus and I . scapularis were active in Fall and Winter. Factors associated with numbers of individuals of A . americanum included day of year, habitat, and latitude. Similar associations were observed when abundance was examined by life-stage. Overall, the picture is one of broadly distributed tick species that shows seasonal limitations in the timing of their questing activity.
Journal Article
High levels of alpha-gal with large variation in the salivary glands of lone star ticks fed on human blood
by
Ghosh, Anuradha
,
Park, Yoonseong
,
Maldonado-Ruiz, L. Paulina
in
631/601
,
631/601/1466
,
Allergies
2023
Tick bites, associated with the secretion of tick saliva containing the xenoglycan galactose-alpha-1, 3-galactose (alpha-gal or aGal), are recognized as the causal factors of alpha-Gal syndrome (AGS; or red meat allergy) in humans. AGS occurs after the increased production of IgE antibodies against aGal, which is found in most mammalian cells, except for the Old World monkey and humans. The aGal sensitization event has been linked to an initial tick bite, followed by consumption of red meat containing the aGal glycan, which triggers the onset of the allergic response resulting in urticaria, anaphylaxis, or even death. In North America, the lone star tick,
Amblyomma americanum
, has been identified as the main culprit for AGS. However, only a subset of the human population exposed to lone star tick bites develops AGS. This suggests the presence of unidentified variables associated with the sensitization event. To evaluate the quantitative variations of the aGal in ticks, we evaluated the differences in aGal levels in different strains of
A. americanum
ticks partially fed on different blood sources using an artificial feeding system and animal hosts. We found significantly higher aGal levels in the female ticks fed on human blood than those fed on the blood of other mammals with large variations among different tick populations and individuals. We propose that host-specific genetic components in the
A. americanum
ticks are involved in the production of high aGal epitope in the tick saliva, which provides a part of the explanation for the variables associated with the AGS sensitization event of the tick bite.
Journal Article
Dogs Leaving the ICU Carry a Very Large Multi-Drug Resistant Enterococcal Population with Capacity for Biofilm Formation and Horizontal Gene Transfer
2011
The enterococcal community from feces of seven dogs treated with antibiotics for 2-9 days in the veterinary intensive care unit (ICU) was characterized. Both, culture-based approach and culture-independent 16S rDNA amplicon 454 pyrosequencing, revealed an abnormally large enterococcal community: 1.4±0.8×10(8) CFU gram(-1) of feces and 48.9±11.5% of the total 16,228 sequences, respectively. The diversity of the overall microbial community was very low which likely reflects a high selective antibiotic pressure. The enterococcal diversity based on 210 isolates was also low as represented by Enterococcus faecium (54.6%) and Enterococcus faecalis (45.4%). E. faecium was frequently resistant to enrofloxacin (97.3%), ampicillin (96.5%), tetracycline (84.1%), doxycycline (60.2%), erythromycin (53.1%), gentamicin (48.7%), streptomycin (42.5%), and nitrofurantoin (26.5%). In E. faecalis, resistance was common to tetracycline (59.6%), erythromycin (56.4%), doxycycline (53.2%), and enrofloxacin (31.9%). No resistance was detected to vancomycin, tigecycline, linezolid, and quinupristin/dalfopristin in either species. Many isolates carried virulence traits including gelatinase, aggregation substance, cytolysin, and enterococcal surface protein. All E. faecalis strains were biofilm formers in vitro and this phenotype correlated with the presence of gelE and/or esp. In vitro intra-species conjugation assays demonstrated that E. faecium were capable of transferring tetracycline, doxycycline, streptomycin, gentamicin, and erythromycin resistance traits to human clinical strains. Multi-locus variable number tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE) of E. faecium strains showed very low genotypic diversity. Interestingly, three E. faecium clones were shared among four dogs suggesting their nosocomial origin. Furthermore, multi-locus sequence typing (MLST) of nine representative MLVA types revealed that six sequence types (STs) originating from five dogs were identical or closely related to STs of human clinical isolates and isolates from hospital outbreaks. It is recommended to restrict close physical contact between pets released from the ICU and their owners to avoid potential health risks.
Journal Article
Unraveling Protein-Metabolite Interactions in Precision Nutrition: A Case Study of Blueberry-Derived Metabolites Using Advanced Computational Methods
by
Ghosh, Anuradha
,
Bhandari, Dipendra
,
Chintapalli, Sree V.
in
Acid-base regulation
,
Acids
,
Algorithms
2024
Metabolomics, the study of small-molecule metabolites within biological systems, has become a potent instrument for understanding cellular processes. Despite its profound insights into health, disease, and drug development, identifying the protein partners for metabolites, especially dietary phytochemicals, remains challenging. In the present study, we introduced an innovative in silico, structure-based target prediction approach to efficiently predict protein targets for metabolites. We analyzed 27 blood serum metabolites from nutrition intervention studies’ blueberry-rich diets, known for their health benefits, yet with elusive mechanisms of action. Our findings reveal that blueberry-derived metabolites predominantly interact with Carbonic Anhydrase (CA) family proteins, which are crucial in acid-base regulation, respiration, fluid balance, bone metabolism, neurotransmission, and specific aspects of cellular metabolism. Molecular docking showed that these metabolites bind to a common pocket on CA proteins, with binding energies ranging from −5.0 kcal/mol to −9.0 kcal/mol. Further molecular dynamics (MD) simulations confirmed the stable binding of metabolites near the Zn binding site, consistent with known compound interactions. These results highlight the potential health benefits of blueberry metabolites through interaction with CA proteins.
Journal Article
The Need to Legalize and Regulate Insider Trading - An Analysis
2021
Insider trading is perceived as a problem across capital mar-kets. The Securities Exchange Board of India (SEBI) created the SEBI (Prohibition of Insider Trading) Regulations, 2015, which criminalizes insider trading. However, insider trading laws have faced several problems at the implementation and enforcement stage. This article considers these problems from the viewpoint of the economic rationale that insider trading should be permitted in capital markets and thus le-galized. These economic arguments have largely been ig-nored by regulators who have continued to come down hard upon insider trading, despite limited success. Moreover, due to concerns related to privacy, insider trading investigations may face greater hurdles in the future. This article takes these factors and economic arguments into consideration and balances them against the regulators' concerns to suggest that insider trading be not only prima facie legalized, but also regulated when there is a breach of fiduciary duties or when there is a dissemination of positive information.
Journal Article
Chemotaxis of Burkholderia sp. Strain SJ98 towards chloronitroaromatic compounds that it can metabolise
by
Jain, Rakesh K
,
Ghosh, Anuradha
,
Sharma, Narinder K
in
Ammonia
,
Bacteria
,
Biological Microscopy
2012
Background
Burkholderia
sp. strain SJ98 is known for its chemotaxis towards nitroaromatic compounds (NACs) that are either utilized as sole sources of carbon and energy or co-metabolized in the presence of alternative carbon sources. Here we test for the chemotaxis of this strain towards six chloro-nitroaromatic compounds (CNACs), namely 2-chloro-4-nitrophenol (2C4NP), 2-chloro-3-nitrophenol (2C3NP), 4-chloro-2-nitrophenol (4C2NP), 2-chloro-4-nitrobenzoate (2C4NB), 4-chloro-2-nitrobenzoate (4C2NB) and 5-chloro-2-nitrobenzoate (5C2NB), and examine its relationship to the degradation of such compounds.
Results
Strain SJ98 could mineralize 2C4NP, 4C2NB and 5C2NB, and co-metabolically transform 2C3NP and 2C4NB in the presence of an alternative carbon source, but was unable to transform 4C2NP under these conditions. Positive chemotaxis was only observed towards the five metabolically transformed CNACs. Moreover, the chemotaxis was induced by growth in the presence of the metabolisable CNAC. It was also competitively inhibited by the presence of nitroaromatic compounds (NACs) that it could metabolise but not by succinate or aspartate.
Conclusions
Burkholderia
sp. strain SJ98 exhibits metabolic transformation of, and inducible chemotaxis towards CNACs. Its chemotactic responses towards these compounds are related to its previously demonstrated chemotaxis towards NACs that it can metabolise, but it is independently inducible from its chemotaxis towards succinate or aspartate.
Journal Article
Fresh Steam-Flaked Corn in Cattle Feedlots Is an Important Site for Fecal Coliform Contamination by House Flies
2015
House flies are a common pest at food animal facilities, including cattle feedlots. Previously, house flies were shown to play an important role in the ecology of Escherichia coli O157:H7; house flies in cattle feedlots carried this zoonotic pathogen and were able to contaminate cattle through direct contact and/or by contamination of drinking water and feed. Because house flies aggregate in large numbers on fresh ( # 6 h) steam-flaked corn (FSFC) used in cattle feed, the aim of this study was to assess FSFC in a cattle feedlot as a potentially important site of fecal coliform contamination by house flies. House flies and FSFC samples were collected, homogenized, and processed for culturing of fecal coliforms on membrane fecal coliform agar. Selected isolates were identified by 16S rRNA gene sequencing, and representative isolates from each phylogenetic group were genotyped by pulsed-field gel electrophoresis. Fecal coliforms were undetectable in FSFC shortly (0 h) after flaking; however, in summer, after 4 to 6 h, the concentrations of fecal coliforms ranged from 1.9 × 10(3) to 3.7 × 10(4) CFU/g FSFC (mean, 1.1 ± 3.0 × 10(4) CFU/g). House flies from FSFC carried between 7.6 × 10(2) and 4.1 × 10(6) CFU of fecal coliforms per fly (mean, 6.0 ± 2.3 × 10(5) CFU per fly). Fecal coliforms were represented by E. coli (85.1%), Klebsiella spp. (10.6%), and Citrobacter spp. (4.3%). Pulsed-field gel electrophoresis demonstrated clonal matches of E. coli and Klebsiella spp. between house flies and FSFC. In contrast, in winter and in the absence of house flies, the contamination of corn by fecal coliforms was significantly (∼10-fold) lower. These results indicate that FSFC is an important site for bacterial contamination by flies and possible exchange of E. coli and other bacteria among house flies. Further research is needed to evaluate the potential use of screens or blowers to limit the access of house flies to FSFC and therefore their effectiveness in preventing bacterial contamination.
Journal Article
Study of methanol-induced phenotypic changes in a novel strain of Acinetobacter lwoffii
by
Jain, Rakesh K
,
Ghosh, Anuradha
,
Goyal, Abhineet
in
Acinetobacter
,
Acinetobacter - classification
,
Acinetobacter - genetics
2007
A Gram-negative bacterial strain designated LS2 isolated from Lahaul-Spiti valley of North India was shown to produce pink pigment while utilizing methanol as sole source of carbon and energy. Interestingly, pigment production was inducible in nature since the organism did not produce any pigment when grown on other carbon sources. Based on phenotypic and phylogenetic characterization the non-pigmented methylotroph was identified as a novel strain of Acinetobacter lwoffii MTCC 8288 (DQ144736). By means of spectral and mass analyses the pigment was characterized as bacterioruberin-like carotenoid molecule. Here, the carotenoid pigment may form an important part of the antioxidant defense mechanism against oxidative stress imparted by methanol. The methanol utilization pathway in strain LS2 was deciphered by showing the presence of functional methanol dehydrogenase and formaldehyde dehydrogenase genes. In addition, to investigate methanol induced physiological changes, comparative fatty acid profile was analysed and distinctive qualitative as well as quantitative differences in fatty acid content were observed. Therefore, we suggest that strain LS2 exhibiting such unique phenotypic property should be assigned a taxonomic position other than the pigmented and non-pigmented methylotrophs.
Journal Article