Antimicrobial resistance tendency and collateral sensitivity of Staphylococcus aureus adapted to antibiotics or extracts of medicinal plants grown in Viet Nam.

Antimicrobial resistance has silently turned into one of the biggest threats to global health, marking the fall of the Golden age of antibiotics. In the search for antibiotic replacement or enhancement, plant-derived natural compounds have attracted lots of interest. Even though firmly believed, the low-resistance tendency of pathogenic bacteria against plant extracts has been scarcely demonstrated. In this study, we investigated the antibacterial activities of diethyl ether extracts from six medicinal plants grown in Viet Nam against Staphylococcus aureus and its variants, which were in vitro adapted to the same extracts. After 30 passages of S. aureus growing under sub-lethal concentrations of plant extracts or antibiotics, the bacteria slowly adapted to the extracts while rapidly resisting the antibiotics. Most of the resulting strains obtained from the adaptation to plant extracts were collaterally sensitive to antibiotics. In contrast, antibiotic-adapted strains showed cross-resistance to both antibiotics and extracts. The findings provided evidence of the low-resistance tendency of S. aureus to antimicrobial plant extracts. It is the first time a collateral antibiotic sensitivity of S. aureus adapted to natural compounds has been observed, suggesting an alternative approach to fight antibiotic resistance.

Effects of sea-level rise on physiological ecology of populations of a ground-dwelling ant.

INTRODUCTION: Sea-level rise is a consequence of climate change that can impact the ecological and physiological changes of coastal, ground-dwelling species. Sea-level rise has a potential to inundate birds, rodents, spiders, and insects that live on the ground in coastal areas. Yet, there is still much to be learned concerning the specifics of these impacts. The red imported fire ant Solenopsis invicta (Buren) excavates soil for its home and is capable of surviving flooding. Because of their ground-dwelling life history and rapid reproduction, fire ants make an ideal model for discovery and prediction of changes that may be due to sea-level rise. There are up to 500,000 individuals in a colony, and these invasive ants naturally have a painful sting. However, observations suggest that colonies of fire ants that dwell in tidally-influenced areas are more aggressive with more frequent stings and more venom injected per sting (behavioral and physiological changes) than those located inland. This may be an adaption to sea-level rise. Therefore, the objective of this study is to elucidate differences in inland and coastal defensiveness via micro-dissection and comparison of head width, head length, stinger length, and venom sac volume. But first because fire ants' ability to raft on brackish tidal water is unknown, it had to be determined if fire ants could indeed raft in brackish water and examine the behavior differences between those flooded with freshwater vs. saltwater. METHODS: To test the coastal-aggression hypothesis, inland colonies and coastal colonies, which experience relatively greater amounts of flooding, specifically regular tidal and windblown water and oscillations (i.e. El Nino Southern Oscillation) from the Gulf of Mexico, were collected. To mimic sea-level rise, the colonies were flooded in salinities that correspond to both their collection site and conditions found in a variety of locales and situations (such as storm surge from a tropical storm). Individual ants were immediately taken from each colony for dissection before flooding, 1-hour into flooding, and 24-hours into flooding. RESULTS AND DISCUSSION: Fire ants use their venom to defend themselves and to communicate alarm or aggression. Dissections and measurement of heads, venom sacs, and stingers revealed both coastal and inland colonies experience an increase in venom sac volume after 24 hours; in fact coastal colonies increased their venom volume by 75% after 24 h of flooding Whether this venom sac enlargement is due to diffusion of water or venom sac production is unknown. These ground-dwelling ants exhibit physiological and behavioral adaptations to ongoing sea-level rise possibly indicating that they are responding to increased flooding. Fire ants will raft on high-salinity water; and sea-level rise may cause stings by flooded ants to be more severe because of increased venom volume.

Laparoscopic living donor right nephrectomy: Assessment of outcome and association of BMI to length of right renal vein. / Nefrectomía laparoscópica derecha de donante vivo: evaluación del resultado y asociación del IMC con la longitud de la vena renal derecha.

AIMS: The aim of this study was to describe outcomes of laparoscopic living donor right nephrectomy (LLDRN) and study factors affecting the length of right renal vein from the donors. MATERIAL AND METHODS: This study was conducted in 60 donors (48 males and 12 females) from January 2016 to December 2017. We performed a retrospective review of consecutive patients who underwent transperitoneal right laparoscopic living donor nephrectomy at our unit. RESULTS: LLDRN was successfully performed in all subjects by the same surgeons. Among 60 cases, 47 donors had single renal artery and vein, 2 cases had one artery and 2 veins, and 5 donors had 2 arteries and one vein, and the rest had 2-3 arteries with 1-3 veins. Operative time was 142.60±33.73min. Warm ischemic time was 2.64±0.76min. The mean hospital stay was 6.69±0.63 days. The median length of right renal vein was 1.92±0.41cm. All transplanted kidneys showed immediate function. No graft losses were recorded. Almost no gender differences were found in study variables except BMI and warm ischemic time, that was higher BMI but shorter warm ischemic time in female versus male donors. Further analysis showed a negative correlation between BMI and right renal vein (r=-0.282, P<0.05), but a positive correlation between operative time and estimate blood loss (r=0.37, P<0.01). CONCLUSIONS: LLDRN is a feasible safe procedure, less traumatic approach, and provides good outcomes kidney for recipients. Notably, in the study group the higher BMI was associated with resulting more difficult LLDRN and kidney transplantation.

Insecticide Transfer Efficiency and Lethal Load in Argentine Ants.

Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/µg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/µg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/µg ant) than did live workers (208.5 amol/µg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/µg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.

Efficacy of bifenthrin treatment zones against red imported fire ant.

Exclusion of ants, particularly red imported fire ant, Solenopsis invicta (Buren), from homes, nursing facilities, hospitals, and electrical housings is an important strategy in urban and rural pest control. We conducted a laboratory bioassay to determine the repellency of granular bifenthrin (Talstar: rate 2.087 kg of formulated product/92.88 m2 or 4.6 lb formulated product/1000 feet2 or 4.2 g active ingredient/92.88 m2) to S. invicta foragers. In the field, we compared the efficacy of three widths (0.3, 2.0, and 3.0 m) of granular bifenthrin-treated zones at the rate 2.087 kg of formulated product/92.88 m2 and investigated the survival of individual ants successfully crossing the respective zones. Granular bifenthrin was nonrepellent to fire ant foragers in the laboratory. The 2.0- and 3.0-m treatment zones provided 100% protection for 7 wk after treatment and provided a reduction in the number of ants breaching the treated zone compared with the control for the remaining 9 wk of the study. This level of control may be tolerable for homeowners and is, therefore, considered an effective treatment for 15 wk after treatment. Hospitals, nursing homes, and electrical boxes would have to be treated on a monthly or bimonthly to remain ant free.

An oral bioassay for the toxicity of hydramethylnon to individual workers and queens of Argentine ants, Linepithema humile.

We have developed an oral bioassay to determine the toxicity of hydramethylnon to individual workers and queens of the Argentine ant, Linepithema humile. We fed seven concentrations of hydramethylnon in suspension to individual workers or queens, determined the amount of hydramethylnon ingested and evaluated the individual ants for mortality 14 days later. At concentrations > or = 0.37 g liter-1, the amount of liquid the queens ingested decreased dramatically, indicating that Argentine ant queens may detect hydramethylnon. Significantly larger volumes of the two highest concentrations of the hydramethylnon suspension were ingested by the workers, compared to the lower concentrations, suggesting that hydramethylnon may act as a feeding stimulant for the workers. Worker mortality was higher than queen mortality at the highest concentrations tested. The highest worker mortality resulted when the ants ingested 1.03 micrograms of hydramethylnon per mg of ant tissue. At the highest concentration (1.0 g liter-1) tested, workers ingested almost 12 times as much active ingredient per mg of body weight as did queens, suggesting that, in order to increase mortality of queens, multiple feedings must occur.

Influence of green lipped mussels (Perna canaliculus) in alleviating signs of arthritis in dogs.

This study evaluated the efficacy of green lipped mussel (GLM), added to a complete dry diet, for alleviating clinical signs of arthritis in dogs. A double-blind longitudinal study design was used with 31 mixed-breed dogs exhibiting varying degrees of arthritis. Each dog was evaluated by a veterinarian and joints were individually scored for degree of pain, swelling, crepitus, and reduction in range of movement. Summation of all scores for an individual dog comprised its total arthritis score. At baseline, dogs were randomly allocated to control and test groups. Both groups were fed the same base dry diet, to which 0.3% GLM powder was added for dogs in the test group. The change in total arthritis score by the end of 6 weeks showed there was significant improvement (P < .05) in the test group versus the control group. Significant improvements were also observed in joint pain and swelling scores in the test group. Changes in joint crepitus and range of joint movement were not significantly different between the test and control groups. These findings provide strong evidence that GLM incorporated into a complete dry diet can help alleviate arthritis symptoms in dogs.

Oral toxicity of abamectin, boric acid, fipronil, and hydramethylnon to laboratory colonies of Argentine ants (Hymenoptera: Formicidae).

Comprehensive laboratory baiting studies with the 4 insecticides abamectin, boric acid, fipronil, and hydramethylnon were conducted against Argentine ant, Linepithema humile (Mayr). Serial dilutions of each insecticide prepared in a 25% sucrose solution were provided for 24 h or 14 d to groups of workers and queens. Sucrose-water baits containing 1 x 10(-5)% fipronil and 0.1% hydramethylnon provided complete mortality of L. humile workers baited for 24 h. Baits containing 1 x 10(-4) and 1 x 10(-5)% fipronil provided 100% kill of queens. In the continuous baiting, 0.5% boric acid, 1 x 10(-6)% fipronil, and 0.025% hydramethylnon provided 100% mortality of workers. The queens and workers provided baits containing 1 x 10(-5)% fipronil and 0.5% boric acid all died within 14 d. Low concentrations of fipronil and boric acid in sucrose may be promising candidates for Argentine ant control.

Altered zinc metabolism contributes to the developmental toxicity of 2-ethylhexanoic acid, 2-ethylhexanol and valproic acid.

It has been hypothesized that the developmental toxicity of certain compounds is, in part, due to maternal toxicity resulting in alterations in zinc (Zn) metabolism that affects the developing conceptus. In the present work the effects of developmentally toxic doses of 2-ethylhexanoic acid (EHXA), 2-ethylhexanol (EHXO), and valproic acid (VPA) on Zn metabolism were investigated in the pregnant rat. In experiment 1, dams were intubated with EHXA (3.13, 6.25, 9.38 or 12.5 mmol/kg), EHXO (6.25, 9.38 or 12.5 mmol/kg), VPA (1.56, 3.13, 6.25 or 9.38 mmol/kg), or corn oil (control; 1.0 ml/kg) at 14:00 h on gestation day (GD) 11.5, intubated with 32 microCi 65Zn at 22:00 h, and then killed at 08:00 h on GD 12.5. At the higher dose levels of EHXA and EHXO, and at all dosages of VPA, the percentage of 65Zn retained in maternal liver was higher, while that in the embryos was lower, than in controls. Chemical-associated changes in 65Zn distribution were associated with increased maternal liver metallothionein (MT) concentrations. In experiment 2, dams were fed diets containing 1, 25 or 97 microg Zn/g from GD 0-16 and intubated with 3.5 mmol EHXA or 1.0 ml corn oil/kg/d from GD 8-15. Dams were killed on GD 16 or 19. High incidences of encephalocele and tail defects were noted in the GD 16 fetuses of EHXA-treated dams fed either the low or adequate Zn diet, the highest incidences being in the low Zn group. On GD 19 the incidence of tail defects tended to be higher in the EHXA groups than in oil-treated controls, the highest incidence occurring in the low Zn EHXA group. Encephalocele was only observed in the low Zn EHXA-treated group. Fetal weight and crown-rump lengths were decreased by EHXA treatment and low dietary Zn. The incidence of rib anomalies was higher in the EHXA-exposed groups than in their respective oil controls. In experiment 3, GD 10.5 embryos collected from control dams were cultured for 48 h in serum from control or EHXA-treated male rats fed 4.5 or 25.0 microg Zn/g diets. Embryos cultured in either EHXA or low Zn sera exhibited delayed development; the addition of Zn to these sera eliminated their developmental toxicity. These results support the hypothesis that certain chemicals which induce maternal toxicity act, in part, to influence embryonic Zn metabolism and trigger abnormal development. Importantly, the teratogenic effects of these chemicals can be modulated by dietary Zn intake.

Drinking water source and reproductive outcomes in Sprague-Dawley rats.

As part of our work on the influence of water source on reproductive outcome, Sprague-Dawley rats were randomized to tap water, bottled water, or deionized water treatment groups, utilizing 160 animals per treatment; animals received the water prior to and during pregnancy. Rats were shipped in four batches (A-D). Batch effects were seen for several reproductive parameters. Because the tap water supply was interrupted by an earthquake resulting in an unbalanced design, primary analyses utilized only batches C and D, which included most of the tap water-treated rats. A treatment effect with respect to resorption frequency was seen that was marginally significant using a fixed-effects analysis of variance (P = 0.053), but not when batch was entered as a random effect (P = 0.36). The data were modeled by logistic regression, controlling for batch, litter size, and batch-treatment interaction. The odds ratio comparing tap to bottled water was 1.8 (95% CI 1.0 to 3.3, P = 0.05), which was similar to the epidemiologic result that prompted this study. The magnitude of this association varied by batch, and the difference in resorption frequency was within the range of variation seen for control animals. Although these findings do not justify public health action at this time, further investigation is warranted.

Comparative effects of 6-week nicotine treatment on blood pressure and components of the antioxidant system in male spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rats.

Hypertension, cigarette smoking, and nicotine augment the clinical significance of other risk factors associated with cardiovascular diseases by mechanisms which are poorly understood. Since altered trace element metabolism and antioxidant status have also been implicated in these diseases, the present study investigated the interaction of nicotine treatment and hypertension on tissue trace element concentrations and select indices of antioxidant status. Spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rats were treated with nicotine, via a time release tablet at an average rate of 75 micrograms/h for 6 weeks. Systolic blood pressure in nicotine-treated SHRs was significantly higher at weeks 3 and 6 of treatment than in the SHR-controls. Blood pressure in WKY rats was not affected by nicotine. Plasma and liver iron concentrations in the nicotine-treated SHR were higher than the SHR-controls and the WKY groups. Nicotine treatment did not affect plasma and liver zinc and copper concentrations or liver manganese (Mn) concentrations. Plasma ceruloplasmin activity was increased by nicotine treatment in the SHRs. Liver Mn superoxide dismutase (MnSOD) activities and glutathione concentrations, and liver and heart glutathione reductase activities, were higher in both groups of SHRs than in the WKY groups. Red cell SOD activity in the nicotine-treated SHR was lower than in the SHR-controls. In summary, blood pressure increased more rapidly in the nicotine-treated SHRs compared to the controls. The marked effects on antioxidant status observed were attributable more to hypertension than to the nicotine treatment.

Influence of 12-week nicotine treatment and dietary copper on blood pressure and indices of the antioxidant system in male spontaneous hypertensive rats.

Nicotine treatment and copper (Cu) deficiency have been associated with an increased production of reactive oxygen species that may contribute to the development and/or progression of cardiovascular diseases (CVD). The present study investigated the influence of dietary Cu intake on the response to chronic nicotine treatment in spontaneous hypertensive rats (SHR) with respect to tissue trace mineral levels, several components of the oxidant defense system, and lipid peroxidation rates. SHR weighing 100-110 g were fed a Cu deficient diet (-Cu) (0.5 microgram Cu/g) for 14 d prior to nicotine treatment. SHR were inserted with tablets that released nicotine at a rate of 75 micrograms/h or placebo (control). Following tablet insertion, rats were fed a control diet (+Cu) (12.0 micrograms Cu/g) or the -Cu diet. Nicotine treatment lasted for 12 wk. Blood pressure (BP) was higher in nicotine-treated SHR than in control SHR at wk 3; BP was unaffected by diet. BP was higher in +Cu nicotine-treated SHR at wk 6 compared to -Cu nicotine and control rats. BP was not affected by nicotine or diet at wk 2. Liver, heart, and brain Cu levels and liver, heart, and red cell CuZn superoxide dismutase and plasma ceruloplasmin oxidase activities were lower in the -Cu SHR than in the +Cu SHR. Liver Fe levels were higher and plasma Fe levels were lower in the -Cu rats than in the +Cu rats. Liver selenium-dependent-glutathione peroxidase (Se-GSH-Px) activity was lower in the -Cu rats than in the +Cu rats; heart and thoracic aorta Se-GSH-Px activity was unaffected by -Cu diet. Thoracic aorta, liver, and heart GSH-reductase activities were unaffected by treatments. Plasma thiobarbituric acid reactive substances (TBARS) were higher in the -Cu than in the +Cu SHR. Liver and heart TBARS production was similar among the groups. These data show that nicotine can exacerbate the development of high BP in susceptible individuals; Cu deficiency did not exacerbate the effects of nicotine.

Zinc status and interleukin-1 beta-induced alterations in mineral metabolism in rats.

Changes in zinc (Zn) metabolism and interleukin-1 beta (IL-1 beta) release occur as part of the physiological response to tissue injury and trauma. In the present study, the influence of Zn status on the response to continuous low-dose IL-1 beta administration was evaluated. Rats were fed 50 micrograms Zn/g (adequate zinc; AZn) or 5 micrograms Zn/g (marginal zinc; MZn) diets for 14 days. On day 15, rats were infused via osmotic minipumps, with IL-1 beta (2.3 ng/hr) or saline (control, C) and euthanized 1, 3, or 7 days later. In the AZn rats, IL-1 beta infusion resulted in increased plasma copper (Cu) concentrations and ceruloplasmin (Cp) activity, and decreased iron (Fe) concentrations throughout the 7d period. These effects were most pronounced on d1 and d3. A similar trend was observed in the MZn rats, but IL-1 beta-induced increases in plasma Cu and Cp activity were less than in the AZn fed rats. In MZn and AZn IL-1 beta infused rats, plasma Zn was decreased on Day 1, and Day 3, respectively, compared with their respective controls. AZn IL-1 beta-infused rats were characterized by high liver Fe, Zn, and metallothionein (MT) concentrations on Day 1; by Day 7, only MT concentrations remained elevated. Liver MnSOD activity was 13%-29% higher in both the AZn- and MZn-IL-1 beta-infused rats than their respective controls on Day 3 and Day 7, with most significant increase observed on Day 7. These data show that Zn status can influence the response to low-dose IL-1 beta; this influence of Zn should be considered when IL-1 beta is given therapeutically.