Gut microbial ecology of the Critically Endangered Fijian crested iguana (Brachylophus vitiensis): Effects of captivity status and host reintroduction on endogenous microbiomes.

Animals often exhibit distinct microbial communities when maintained in captivity as compared to when in the wild. Such differentiation may be significant in headstart and reintroduction programs where individuals spend some time in captivity before release into native habitats. Using 16S rRNA gene sequencing, we (i) assessed differences in gut microbial communities between captive and wild Fijian crested iguanas (Brachylophus vitiensis) and (ii) resampled gut microbiota in captive iguanas released onto a native island to monitor microbiome restructuring in the wild. We used both cloacal swabs and fecal samples to further increase our understanding of gut microbial ecology in this IUCN Critically Endangered species. We found significant differentiation in gut microbial community composition and structure between captive and wild iguanas in both sampling schemes. Approximately two months postrelease, microbial communities in cloacal samples from formerly captive iguanas closely resembled wild counterparts. Interestingly, microbial communities in fecal samples from these individuals remained significantly distinct from wild conspecifics. Our results indicate that captive upbringings can lead to differences in microbial assemblages in headstart iguanas as compared to wild individuals even after host reintroduction into native conditions. This investigation highlights the necessity of continuous monitoring of reintroduced animals in the wild to ensure successful acclimatization and release.

Dynamics of toxigenic Clostridium perfringens colonisation in a cohort of prematurely born neonatal infants.

BACKGROUND: Clostridium perfringens forms part of the human gut microbiota and has been associated with life-threatening necrotising enterocolitis (NEC) in premature infants. Whether specific toxigenic strains are responsible is unknown, as is the extent of diversity of strains in healthy premature babies. We investigated the C. perfringens carrier status of premature infants in the neonatal intensive care unit, factors influence this status, and the toxic potential of the strains. METHODS: C. perfringens was isolated by culture from faecal samples from 333 infants and their toxin gene profiles analysed by PCR. A survival analysis was used to identify factors affecting probability of carriage. Competitive growth experiments were used to explore the results of the survival analysis. RESULTS: 29.4% of infants were colonized with C. perfringens before they left hospital. Three factors were inversely associated with probability of carriage: increased duration of maternal milk feeds, CPAP oxygen treatment and antibiotic treatment. C. perfringens grew poorly in breast milk and was significantly outperformed by Bifidobacterium infantis, whether grown together or separately. Toxin gene screening revealed that infants carried isolates positive for collagenase, perfringolysin O, beta 2, beta, becA/B, netB and enterotoxin toxin genes, yet none were observed to be associated with the development of NEC. CONCLUSIONS: Approximately a third of preterm infants are colonised 3 weeks after birth with toxin gene-carrying C. perfringens. We speculate that increased maternal breast milk, oxygen and antibiotic treatment creates an environment in the gut hostile to growth of C. perfringens. Whilst potentially toxigenic C. perfringens isolates were frequent, no toxin type was associated with NEC. TRIAL REGISTRATION: clinicaltrials.gov NCT01102738, registered 13th April 2010.

Antibacterial effects of grape extracts on Helicobacter pylori.

Anti-Helicobacter pylori activities were determined by agar dilution, confocal laser scanning microscopy, and cell proliferation assays following treatment with various grape extracts. Muscadine grape skin possessed the strongest activity, followed by grape synergy (skin and seed) and seed, suggesting that higher phenolic levels do not necessarily determine overall anti-H. pylori efficacy.

Prevalence of antibiotic-resistant bacteria in herbal products.

The objective of this study was to determine the prevalence of antibiotic-resistant bacteria in various herbal products. Twenty-nine herbal supplements (18 traditional and 11 organic products) were purchased from stores and analyzed microbiologically. Total bacterial counts were determined by pour plate and surface spreading on tryptic soy agar (TSA). Antibiotic-resistant bacteria were enumerated on TSA supplemented with ceftriaxone (64 microg/ml) or tetracycline (16 microg/ml). Total bacterial counts ranged from <5 to 2.9 x 10(5) CFU/g. Ceftriaxone- and tetracycline-resistant bacteria were detected in ground garlic samples at 1.1 x 10(2) CFU/g and 3.0 x 102 CFU/g, respectively. Traditional and organic onion powder samples contained tetracycline-resistant bacteria at 17 and 28 CFU/g and ceftriaxone-resistant bacteria at 35 and 2.0 x 10(3) CFU/g, respectively. Other products such as ginger, rosemary, mustard, and goldenseal contained low levels of resistant bacteria. Fifty-two isolates were further evaluated against nine antibiotics, and the prevalence of antibiotic resistance was in the following order: ampicillin, nalidixic acid, trimethoprim, ceftriaxone, and streptomycin. Resistant bacteria were identified as Bacillus spp., Erwinia spp., and Ewingella americana. Staphylococcus spp., Enterobacter cloacae, and Stenotrophomonas maltophilia also were isolated. The presence of antibiotic-resistant bacteria and pathogens in these herbal products suggests that production and use of these products may need further evaluation.