Fecal Monitoring Research Articles

The many uses of non‐invasive faecal steroid monitoring in zoo and wildlife species

During the past two decades, techniques for faecal steroid analysis have been developed and have been used for research with mammalian, bird and, to a lesser extent, reptile, amphibian and fish species. Various techniques for the analysis of reproductive (oestrogen, androgen, progestagen) and adrenocortical (glucocorticoids) steroid hormones have been established and have been applied to a wide range of research questions studying captive and free‐ranging wildlife, as well as domestic and laboratory species. Because of species‐specific differences in steroid metabolism in even closely related species, careful validation of assay methods is necessary in order to generate meaningful and accurate results. For future research and management of free‐ranging and captive wildlife, the great potential of non‐invasive endocrine monitoring will be utilized more than ever. In light of this, captive wildlife species are ideal research subjects, as longitudinal sample collection is possible and studies connecting physiology, endocrinology, reproduction and stress with various social and/or environmental factors can be carried out and can be analysed to determine how they impact animal health.

Quo vadis source tracking? Towards a strategic framework for environmental monitoring of fecal pollution

Advances in microbial source tracking (MST) have largely been driven by the need to comply with water quality standards based on traditional indicator bacteria. Recently, a number of culture-independent, and library-independent methods based on polymerase chain reaction (PCR) have been gaining popularity among source trackers. However, only a limited number of these methods have been successfully used in field applications, primarily due to the fact that many of them are still being developed. In this critical outlook, we examine different viewpoints associated with the practical use of MST to identify critical research gaps, propose a priority-based timeline to address them, and outline emerging technologies that will likely impact the future of source tracking. We propose that it is necessary to consider each of these aspects in order to advance towards a unifying framework in source identification, so that fecal pollution monitoring can be reliably used for comprehensive environmental microbial monitoring, to develop risk assessment models, and to implement and validate adequate management practices.

Reproductive endocrinology of the largest dasyurids: Characterization of ovarian cycles by plasma and fecal steroid monitoring. Part I. The Tasmanian devil ( Sarcophilus harrisii)

There is a strong body of knowledge on the reproductive endocrinology of macropods, but little detailed information is available on the hormonal control of reproduction in other marsupials. This study used plasma and fecal sex steroid monitoring to characterize the estrous cycle of the largest extant dasyurid—the Tasmanian devil ( Sarcophilus harrisii). A pro-estrous pulse in plasma progesterone (1.33 ± 0.2 ng/ml) occurred several weeks prior to onset of the luteal phase (LP), resulting in a characteristic biphasic pattern during the estrous cycle. This brief, pro-estrous progesterone pulse was associated with a predominantly cornified vaginal smear, and copulation in females paired with males. Mean luteal progesterone concentrations (5.28 ± 0.8 ng/ml) were sustained and peaked around day 15 from luteal onset; thereafter, concentrations declined precipitously and returned to baseline around day 25. Females that did not produce young returned to estrus after 33.7 ± 5.9 days. Fecal 20α-OH-pregnanes analyzed in a pregnanediol assay (PgD) were excreted in consistently higher levels than 20-oxo-pregnanes, but the pattern was similar for the two metabolites, and significantly correlated with fluctuations in plasma progesterone. Fecal total estrogen concentrations were highest during the follicular phase (FP) and accompanied a pro-estrous pulse in fecal progestagens. The mean duration of the estrous cycle was ∼32 days, with a FP of around 14 days (range 8–23 days), and a luteal phase of around 18 days (range 12–25 days). There were no differences in the length of the LP between mated and non-mated cycles. Gestation length was 17.9 ± 1.0 days (range 14–22 days). Fecal steroid monitoring revealed significant differences between the pattern of progestagens and estrogen concentrations during the pregnant and non-mated estrous cycle, suggesting maternal endocrine recognition of pregnancy in the Tasmanian devil.

Reproductive endocrinology of the largest Dasyurids: Characterization of ovarian cycles by plasma and fecal steroid monitoring.: Part II. The spotted-tailed quoll ( Dasyurus maculatus)

Dasyurids exhibit a range of breeding patterns from semelparity through to an aseasonally polyestrous strategy, but detailed information on the reproductive endocrinology of many species is unavailable. This study aimed to extend our comparative understanding by characterizing the ovarian cycle of the spotted-tailed quoll ( Dasyurus maculatus) through measurement of plasma progesterone, and also to investigate fecal sex steroid monitoring as an alternative, non-invasive technique. Longitudinal profiles revealed a biphasic pattern of plasma progesterone, with a significant pro-estrous pulse (0.97 ± 0.3 ng/ml) up to several weeks prior to onset of the luteal phase (LP). This pro-estrous period was associated with a predominantly cornified vaginal smear, onset of estrus behaviors and copulation. Mean luteal values for plasma progesterone were several fold higher (2.18 ± 1.10 ng/ml) than during the follicular phase (FP) (0.75 ± 0.02 ng/ml), and were sustained for approximately one month. Fecal progestagens and plasma progesterone were significantly positively associated during the estrous cycle. During the breeding period average concentrations of fecal total estrogens and pregnanediol (PgD) were significantly elevated. Ovarian activity during the FP was marked by increases in fecal estrogens, and rises in PgD which were sustained during the LP. In non-mated females the mean duration of the FP was significantly extended, being approximately twice as long (19.4 ± 4.0 d) as for mated females (8.3 ± 1.9 d) indicating coitus has some role in timing of ovulation in this species. This study has provided important new information on the reproductive biology of the female spotted-tailed quoll, and further demonstrated the usefulness of non-invasive endocrine techniques for monitoring ovarian cycles in marsupials.

Fecal steroid monitoring for assessing gonadal and adrenal activity in the golden eagle and peregrine falcon

We examined the efficacy of noninvasive monitoring of endocrine function via fecal steroid immunoassays in the golden eagle and peregrine falcon. High-pressure liquid chromatography analyses of fecal glucocorticoid metabolites (fGCM) revealed that minor percentages of immunoreactive fGCM co-eluted with [(3)H]corticosterone in both sexes of the eagle (2.5-2.7%) and falcon (7.5-11.9%). In contrast, most fecal estrogen metabolites in eagle and falcon females co-eluted with radiolabeled estradiol-17beta ([(3)H]; 57.6, 64.6%, respectively) or estrone ([(3)H]; 26.9, 4.1%, respectively). Most fecal progestin metabolite immunoreactivity in the female eagle (24.8%) and falcon (21.7%) co-eluted with progesterone ([(14)C]). Most fecal androgen metabolite immunoreactivity in eagle (55.8%) and falcon (63.7%) males co-eluted with testosterone ([(14)C]). Exogenous adrenocorticotropin hormone induced increased fGCM excretion above pre-treatment in both species, but only significantly (P < 0.05) in the eagle. Both species showed increased fGCM after saline administration, suggesting the detection of 'handling stress.' Both species exhibited enterohepatic and renal recirculation of administered steroids as demonstrated by biphasic and triphasic excretion patterns. Thus, noninvasive fecal hormone monitoring is a valid and promising tool for assessing gonadal and adrenal status in rare and threatened birds-of-prey.

Novel detection of Escherichia coli β-d-glucuronidase activity using a microbially-modified glassy carbon electrode and its potential for faecal pollution monitoring

The electrochemical detection of Escherichia coli beta-D-glucuronidase activity as a means of monitoring water pollution by faecal material was investigated using separate Moraxella- and Pseudomonas putida-modified glassy carbon electrodes. The former was more sensitive and selective. The Moraxella-modified biosensor was 100 times more rapid and sensitive than the spectrophotometric detection of beta-D-glucuronidase activity. The experimental limit of detection of the biosensor was two c.f.u. per 100 ml polluted water sample within 20 min. The biosensor gave a linear response to commercial beta-D-glucuronidase concentration between 0.2 ng and 2 microg ml(-1). The biosensor detected activity of beta-D-glucuronidase from viable but non-culturable (VBNC) cells and can therefore serve as a presence or absence device for rapid water quality monitoring.

Applying Fecal Endocrine Monitoring to Conservation and Behavior Studies of Wild Mammals: Important Considerations and Preliminary Tests

The desire to apply fecal steroid metabolite monitoring to key questions in conservation biology and behavioral ecology has steadily increased over the past decade. In particular, the measurement of fecal glucocorticoid metabolites, which reflect changes in an individual's adrenal activity, and are thus a measure of the stress response, has become a sought-after tool for conservation biologists and behaviorists alike. The noninvasive nature of this method facilitates longitudinal physiological monitoring concomitant with behavioral observations and other noninvasive ecological and biological data collection, providing an increased level of insight and complexity that was previously impossible to obtain. While the method has huge potential, some doubt is beginning to emerge regarding its general applicability to field studies. This doubt may largely result from some misconceptions and lack of knowledge about the method itself. The perceived simplicity of this methodology has led some to believe that it is ...

Ovarian activity in Arabian leopards (Panthera pardus nimr): sexual behaviour and faecal steroid monitoring during the follicular cycle, mating and pregnancy

The Arabian leopard is a critically endangered subspecies endemic to the Arabian Peninsula. A fundamental understanding of the ovarian activity of the leopard is important to enhance the success with which it breeds in captivity. The objective of the present study was to characterise the endocrinology of the follicular cycle, ovulation and pregnancy in captive females using faecal steroid hormone analyses and observations of sexual behaviour. The follicular cycle of the leopard was shown to last 18-23 days based on the interval between consecutive peaks of faecal oestrogen conjugates, and the occurrence of silent heats was high. Puberty had commenced at 2 years of age, but faecal steroid profiles did not match those of the adult female until 3 years of age. No seasonal change in ovarian steroid excretion was observed, although behavioural oestrus was suppressed in summer. Significant rises in faecal progestagen concentrations were only recorded in mated leopards, indicating that these females were strictly induced ovulators. However, only 60% of these mating periods were ovulatory. Progestagen concentrations during pregnancy were significantly higher than those of the non-pregnant luteal phase. The average duration of the non-pregnant and pregnant luteal phases was 39 and 97 days, respectively. The basic features of the reproductive cycle of the Arabian leopard described here form an important foundation for further study into its reproduction.

Comparison of total and faecal coliforms as faecal indicator in eutrophicated surface water

The aim of this study was to evaluate the use of total coliforms (TC) and faecal coliforms (FC) using a membrane filtration method for precise monitoring of faecal pollution in Korean surface water. The samples were collected in Korea from both main rivers and their tributaries. Presumptive TC * FC were enumerated. The ratios of presumptive FC to TC were not constant, but varied widely, and TC were difficult to enumerate because of overgrowth by background colonies. For FC this was not the case. Seven hundred and three purified strains of presumptive TC * FC and their background colonies were biotyped using API 20E. Among 272 presumptive TC, non-faecal related species, Aeromonas hydrophila dominated (34.6%) and E. coli accounted for only 5.1%. In contrast, E. coli made up 89% of the 209 presumptive FC. Furthermore, of 164 background colonies on Endo Agar LES, 54.9% was A. hydrophila, while background colonies on m-FC Agar were few (58 strains), and despite their atypical colony appearance, most of them were biotyped as enteric bacteria. These results reveal that the detection of FC rather than TC using m-FC Agar is more appropriate for faecal pollution monitoring in eutrophicated surface water located in a temperate region.

THE EFFECT OF THE MALE BUSH DOG (SPEOTHOS VENATICUS) ON THE FEMALE REPRODUCTIVE CYCLE

Abstract In a 2-year study of the bush dog (Speothos venaticus), a small canid from Central and South America, we examined the reproductive physiology of mature females and the effect of male presence on the incidence and timing of ovulation. Fecal hormones, vulvar measurements, and mating behavior were used to characterize reproductive cycle dynamics. As described for all other canids, female bush dogs have an obligate pseudopregnancy after an infertile mating or ovulation without mating. However, the female cycle is not fixed to a single rigid breeding season each year, as in most canids. Unlike other canids, the presence of a male was associated with shortened interestrous intervals and increased number of estrous cycles. Examination of preliminary testosterone data from males showed a nonseasonal pattern suggesting that males have year-round, not seasonal, sperm production. The results from this study, including the validation of the noninvasive fecal hormone monitoring technique used, can provide man...

NONINVASIVE MONITORING OF STRESS HORMONE LEVELS IN A FEMALE STELLER SEA LION (EUMETOPIAS JUBATUS) PUP UNDERGOING REHABILITATION

Steller sea lions (Eumetopias jubatus) rarely strand in areas monitored by humans, and there is little published data on the diseases, parasites, nutritional state, and stress levels of Steller sea lions in the wild. In May 2002, a female Steller sea lion pup (EJS-02-01) was sighted separated from her mother after strong storms in Southeast Alaska. After 5 days of observations, EJS-02-01 was transferred to the Alaska SeaLife Center (ASLC) in Seward, Alaska. During 11 mo of rehabilitation at ASLC, body weight was monitored and opportunistic fecal samples (n = 86) were analyzed for corticosterone concentrations. Fecal corticosterone concentrations ranged from 15 to 3,805 ng/ g for EJS-02-01. Peak corticosterone values reflected responses to acute stressors during rehabilitation. EJS-02-01 was successfully released at Gran Point, Alaska, in April 2003. Fecal corticosterone assay monitoring provided a valuable tool to monitor various stressors and is useful in monitoring long-term situations like rehabilitation.

Dietary Inulin Intake and Age Can Affect Intestinal Absorption of Zinc and Copper in Rats

Nondigestible inulin-type fructan intake can stimulate intestinal mineral absorption in both humans and animals. However, this stimulatory effect may depend on experimental conditions such as the duration of the experience, mineral levels in the diet, and the animal's physiological status. The aim of this study was to determine the effect of inulin intake on Zn and Cu absorption in rats at different ages. Male Wistar rats (n = 80) of 4 different ages (2,5, 10, and 20 mo) were randomly assigned to a control group or a group administered 3.75% inulin in their diet for 4 d followed by 7.5% inulin for 26 d. Absorption of Zn67 and Cu65 was determined on d 21 of the experiment by fecal monitoring using Zn67 and Cu65 isotopes. Zn and Cu status was also assessed. Absorption of Zn67 and Cu65 was significantly lower in 11- and 21-mo-old rats than in 3- and 6 mo-old-rats. Moreover, inulin intake significantly increased Zn67 and Cu65 absorption. In conclusion, age and dietary inulin intake can significantly affect intestinal absorption of zinc and copper in rats. Further studies are required to explore this effect over longer periods of inulin intake and to test the effects of inulin in humans.

Fluorescent Antibody‐Viability Staining and β‐Glucuronidase Assay as Rapid Methods for Monitoring Escherichia coli Viability in Coastal Marine Waters

A faecal pollution monitoring of coastal Messina waters was performed by comparing three (microscopic, enzyme, and culture) methods. Evidence of Escherichia coli cells (29.99 to 96.79% of the total enteropathogenic serotypes) retaining their viability into the marine environment was shown. β‐Glucuronidase activity rates suggested that living cells were also metabolically active. Heavily polluted sites were detected, where improperly treated urban wastes were discharged. Significant relationships between microscopic and enzymatic data proved both methods to be suitable alternatives to the culture method for E. coli detection, improving environmental quality assessment.

Dysprosium as a nonabsorbable fecal marker in studies of zinc homeostasis

Dysprosium is a nonabsorbable rare earth element that has had successful application as a marker for fecal excretion of unabsorbed zinc. Our goals were 1) to evaluate the efficacy of administering dysprosium with all meals over several days as a method of determining the completeness of fecal collections, 2) to determine the similarity of gastrointestinal transit kinetics and excretion patterns of dysprosium and zinc tracer administered simultaneously over several days, and 3) to evaluate alternative methods of using the data for fecal excretion of orally administered zinc tracer and dysprosium to measure the fractional absorption of zinc. 70Zn and dysprosium were administered orally with all meals for 5 consecutive days to 7 healthy, free-living adults consuming a constant diet based on habitual intake. Additional tracers, 67Zn and 68Zn, were administered intravenously. Urine and fecal samples were collected during tracer administration and for 8 d after the last dose. Isotope ratios were measured in urine and feces, and total zinc and dysprosium were measured in fecal samples. The mean recovery of dysprosium was 101.3 +/- 2.4%. The zinc oral tracer and dysprosium had similar fecal excretory patterns; the correlation coefficient for 70Zn and dysprosium in fecal samples exceeded 0.99 (P < 0.0001) for each subject. Fractional zinc absorption measurements using various dysprosium methods correlated well (r > 0.95) with those from the fecal monitoring and dual-isotope-tracer ratio methods. Administration of dysprosium is a useful means of determining the completeness of fecal collections and of measuring zinc absorption.

Dietary inulin intake and age can significantly affect intestinal absorption of calcium and magnesium in rats: a stable isotope approach

Backgroundprevious studies have shown that non-digestible inulin-type fructan intake can increase intestinal mineral absorption in both humans and animals. However, this stimulatory effect on intestinal absorption may depend on experimental conditions such as duration of fermentable fiber intake, mineral diet levels and animals' physiological status, in particular their age.Objectivesthe aim of this study was to determine the effect of inulin intake on Ca and Mg absorption in rats at different age stages.Methodseighty male Wistar rats of four different ages (2, 5, 10 and 20 months) were randomized into either a control group or a group receiving 3.75% inulin in their diet for 4 days and then 7.5% inulin for three weeks. The animals were fed fresh food and water ad libitum for the duration of the experiment. Intestinal absorption of Ca and Mg was determined by fecal monitoring using stable isotopic tracers. Ca and Mg status was also assessed.Resultsabsorption of Ca and Mg was significantly lower in the aged rats (10 and 20 mo) than in the young and adult rat groups. As expected, inulin intake increased Ca and Mg absorption in all four rat groups. However, inulin had a numerically greater effect on Ca absorption in aged rats than in younger rats whereas its effect on Mg absorption remained similar across all four rat age groups.Conclusionthe extent of the stimulatory effect of inulin on absorption of Ca may differ according to animal ages. Further studies are required to explore this effect over longer inulin intake periods, and to confirm these results in humans.

Studies on zinc bioavailability from a representative diet in Chinese urban women of childbearing age using a double label stable isotope technique

The objectives of the study were to determine dietary zinc bioavailability by using a double label stable isotope technique, and to identify the zinc content and levels of some possible factors which may affect zinc utilization in a typical representative Chinese urban diet. Twenty urban women of childbearing age were fed a diet extrinsically labeled with 67Zn and received intravenous (i.v.) injections of 70Zn. Fecal monitoring, urine monitoring and chemical balance technique were used simultaneously for comparisons. Isotopic enrichment in feces and urine after oral and i.v. administration of stable zinc isotopes was measured to determine the ways of zinc absorption. The mean (±SD) zinc intake from the representative Chinese diet was 10.22±0.80 mg/day, which is lower than the reference nutrient intake (RNI) level (11.5 mg/day), and mainly came from the subsidiary foods (63%). The mean dietary Fe/Zn weight was 1.1±0.1. The phytate/zinc molar ratio in the diet was about 3:1. The phytic acid×Ca/zinc molar ratio in the diet was about 45:1. The apparent and true absorption rates of 67Zn were 36.2±9.7% and 38.2±10.1%, respectively, which were higher than the apparent absorption determined by balance technique (29.7±10.6%). The mean fractional absorption (FA) determined in urine was 35.7±13.3. In conclusion, the subsidiary food is the main source of dietary zinc in this typical diet. The extrinsic labeling technique by use of stable isotopes was more reliable and accurate to determine zinc absorption. Moreover, the double isotopic tracer ratio (DITR) technique applied to urine samples was a more practical and valuable way to evaluate zinc absorption than other methods. It can be speculated that iron and phytic acid might not be the main inhibitors in the representative Chinese diet.

Strongyliden beim Pferd. I. Resistenzentwicklung gegen Anthelminthika

Small strongyles (cyathostomes) that are resistant against anthelmintics have become a major problem in equine medicine in the recent years. In many European countries benzimidazole-resistant cyathostomes are widespread and are now present in well over 50% of equine populations investigated. In contrast, resistance against ivermectin has not been reported despite its widespread use in the recent years. Optimising the frequency of treatments based on quantitative faecal monitoring is of great importance to preserve remaining anthelmintic efficacy.

Absorption of Selenium from Wheat, Garlic, and Cod Intrinsically Labeled with Se-77 and Se-82 stable Isotopes

There is limited information on the absorption of selenium from different foods in humans because of technical difficulties associated with isotopic labeling of dietary selenium. Wheat, garlic, and cod fish were intrinsically labeled with Se-77 or Se-82 stable isotopes. Labeled meals were fed in random order to 14 adults, with a minimum washout period of six weeks between each test meal. Apparent absorption was measured as luminal loss using a fecal monitoring technique over an 8-day period. Plasma appearance of the isotope was measured at 7, 24, and 48 hours post-ingestion. Selenium absorption (+/- SD) was significantly higher (p < 0.001) from wheat (81.0 +/- 3.0%) and garlic (78.4 +/- 13.7%) than from fish (56.1 +/- 4.3%). Lowest plasma concentration was observed after the fish meal at all three time points, with a peak at 24 hours, whereas wheat produced the highest plasma concentration at all three time points and peaked at 7 hours. Selenium absorption from wheat and garlic was higher than from fish, and inter-individual variation was low. Form of selenium and food constituents appear to be key determinants of post-absorptive metabolism.

Use of mathematical modeling to study copper metabolism in humans

An improved understanding of copper metabolism is needed to derive more precise estimates of dietary requirements. The objectives were to validate a method for estimating endogenous losses of copper, test whether a simple model can predict true absorption from the plasma appearance of labeled copper, and develop a compartmental model for copper metabolism by using stable isotopes. A stable isotope of copper was intravenously administered to 6 men, and fecal samples were collected for 14 d. Four weeks later the study was repeated, but with an oral dose, and blood samples were collected for 7 d and fecal samples for 14 d. There was no significant difference (P = 0.48) in the estimated endogenous loss of copper calculated by using either the excreted intravenous dose (x +/- SD: 32 +/- 5%) or the absorbed and excreted oral dose (35 +/- 2%). A simple mathematical model fitted to plasma isotope appearance data estimated true absorption to be 8 +/- 2% compared with 48-49% measured by fecal monitoring. A more complicated compartmental model predicted that, when newly absorbed copper first enters the blood, 74% is removed by the liver and 99% is bound to ceruloplasmin in the plasma. The exchangeable pool of copper was estimated to be 43 +/- 30 mg. Daily endogenous losses were predicted to be 2.4 mg. The results showed that fecal monitoring is the only method that can reliably measure labeled copper absorption, and it is not necessary to administer an intravenous dose of copper to estimate endogenous losses. The compartmental model provides new insights into human copper metabolism.

Non-invasive faecal steroid monitoring of ovarian and adrenal activity in farmed blue fox ( Alopex lagopus) females during late pregnancy, parturition and lactation onset

In the semi-domesticated blue fox, handling stress may influence reproductive performance and increase perinatal pup loss. Ovarian and adrenal steroids were analysed in faecal samples collected from mid-gestation through the first week of lactation in 40 female blue foxes to characterize hormone patterns during this important reproductive period. Daily faecal samples were collected from 40 foxes during 30 pregnancies, one late abortion and nine bred-matched non-pregnancies. Mean concentrations of faecal progestagens over the 10 days before birth were significantly higher in pregnant compared to non-pregnant females (51 ± 1.50 μg/g versus 36 ± 3.72 μg/g, respectively; P < 0.01). From 10 to 3 days before whelping, total faecal oestrogen concentrations also were higher ( P < 0.01) in pregnant (1082 ± 41.69 ng/g) than non-pregnant (628 ± 72.43 ng/g) foxes, before declining to non-pregnant values (402 ± 24.88 ng/g) after parturition. Overall mean faecal corticoid concentrations from 3 to 20 days before whelping differed between pregnant and non-pregnant foxes (128 ± 3.11 ng/g versus 103 ± 5.86 ng/g, respectively; P < 0.01). Furthermore, in pregnant foxes, corticoid excretion increased further from 2 days before to 3 days after whelping (216 ± 13.71 ng/g; P < 0.01). Thereafter, corticoid concentrations were similar between pregnant and non-pregnant females ( P > 0.05). In sum, the faecal steroid hormone patterns for oestrogens and progestagens were similar to those previously obtained by analyses of fox serum hormones, with both steroids being higher in pregnant than non-pregnant foxes at the end of gestation. The elevation in corticoid concentrations in pregnant females suggests that adrenal activation is involved in the initiation of parturition in the blue fox. Thus, faecal steroid analyses can be used to monitor ovarian activity during pregnancy and pseudopregnancy in farmed blue fox females.