Plant Species Over-Occupancy Indicates River Valleys Are Natural Corridors for Migration

River valleys are considered natural corridors for migration of plant species, however, there is a lack of studies confirming higher colonisation rates of plant species in these areas. We compare plant species-richness between ancient and recent forests, and those located in a river valley with those located in the surrounding landscape. We hypothesise that, close to a river, higher plant species-richness will be associated with recent forests thus indicating a higher colonisation rate. The study area includes part of the Elbe River Valley and its surrounding landscape in the Czech Republic. We sampled an equal number of recent and ancient forests but lying at different distances from the river. We used generalised linear models to test the effect of distance from the river in dependence upon forest continuity (recent/ancient forest) on two plant species-richness categories, i.e. richness of forest species and overall species richness. In the surrounding landscape, higher richness of forest species was associated with ancient forests, whereas overall species richness was comparable. In the river valley, richness of forest species as well as overall species richness was higher in the recent forests. Recent forests in the river valley were more saturated by plant species than those in the surrounding landscape, indicating that in the river valley the colonisation rate of plant species is higher. These results confirm the importance of river valleys as natural corridors for migration of plant species.

Conjunctival colonisation and antibiotic resistance of coagulase-negativeStaphylococcusafter cataract surgery: a 6-month longitudinal study at a medical centre in Taiwan

ObjectiveTo explored 6-month longitudinal changes in conjunctival colonisation and antibiotic resistance profiles of coagulase-negativeStaphylococcus(CNS) after cataract surgery with 1 month tobramycin treatment.DesignProspective cohort study between 1 August 2012, and 31 July 2013.SettingA single medical centre in Taiwan.ParticipantsA total of 128 Taiwanese patients with 46.9% of male participants.InterventionsSamples from the conjunctival sacs of both operation (OP) and non-OP eyes were obtained separately before cataract surgery and at 1, 3 and 6 months after surgery. Tobramycin (0.3%) treatment was applied four times daily for 1 month postoperatively.Main outcome measureIdentification of CNS isolates and their antibiotic susceptibility by using disk diffusion or E-test.ResultsCNS was detected in 24.2% of patients at baseline. During postoperative follow-up, the CNS colonisation rate did not decrease in either eye but showed an increasing trend in the OP eyes at 1 month (p=0.06). The colonisation rate showed no significant difference between the OP and non-OP eyes from baseline to a specific follow-up. We observed a significant increase (p<0.05) in resistance to tobramycin at 1 month and to ciprofloxacin at 3 months in the OP eyes and to trimethoprim/sulfamethoxazole at 1 month and 3 months and to oxacillin at 6 months in the non-OP eyes.ConclusionsDuring the 6-month postoperative follow-up, 0.3% tobramycin administration failed to reduce CNS colonisation but increased resistance to several antibiotics. Postoperative antibiotic treatment may be replaced by other evidence-endorsed prophylactic routines.

Effects of pre-farrowing sow vaccination against Mycoplasma hyopneumoniae on offspring colonisation and lung lesions

This study investigated Mycoplasma hyopneumoniae colonisation and lung lesions at slaughter in pigs from vaccinated (V) and non-vaccinated (NV) sows, in two herds (A and B). In each herd, two sow batches were V against M. hyopneumoniae with a commercial bacterin at six and three weeks before farrowing and two sow batches remained NV. From each sow batch, laryngeal swabs were collected from the litters of five primiparous sows at weaning and seven days post-weaning. All samples were tested for M. hyopneumoniae by nested PCR. In total, 488 piglets were sampled. At slaughter, the extent of Mycoplasma-like pneumonia lesions (lung lesion score (LLS)) was assessed. The colonisation rates with M. hyopneumoniae at weaning and seven days post-weaning were (V-A=14.2, NV-A=20.0 (P=0.225); V-B=0.9, NV-B=0.8 (P=0.948)) and (V-A=0.8, NV-A=7.0 (P=0.039); V-B=1.8, NV-B=2.5 (P=0.738)), respectively. The average LLS (in per cent) was V-A=15.5, NV-A=26.4 (P=0.021); V-B=9.7, NV-B=8.4 (P=0.541). In conclusion, in herd A, with a substantially higher level of piglet colonisation at weaning than herd B, offspring from V sows had a significantly lower colonisation rate seven days post-weaning and a significantly lower LLS at slaughter compared with the offspring of the NV sows. This implies that sow vaccination might be useful for control of M. hyopneumoniae infections, although significant results may not be achieved at all times (such as in herd B).

Group B streptococcus colonisation in pregnant women at Dr. George Mukhari Hospital, South Africa

The aim of the study was to estimate group B streptococcus (GBS) colonisation in pregnant mothers using selective enrichment broth and solid media for culturing GBS. Vaginal and rectal swabs were collected from 413 pregnant women for GBS culture at recruitment stage. Direct plating and enrichment broth culture methods were compared by using the same swab samples. The swabs were cultured on colistin nalidixic agar (CNA) plate and incubated at 37°C and examined after 18-24 h. The samples which were culture negative on a CNA agar plate were then inoculated into a Todd-Hewitt enrichment broth to recover any GBS present that was not recovered on the solid agar. With the CNA agar plate, the samples were cultured separately to enable identification of colonised sites such as vaginal sites or rectal sites. Rectal and vaginal swabs were inoculated into Todd-Hewitt enrichment broth at the same time in the same tube. The GBS colonisation rate in pregnant women was 30.9% (128/413). The CNA agar plate recovered 45.3% (58/128) of the GBS isolates, whereas 54.7% (70/128) isolates were recovered from Todd-Hewitt broth. Pregnant women of various ages were found to be at risk of GBS colonisation. The colonisation rate was however highest among women of 25–29 age groups as compared with other age groups. Detection of group B streptococcus improved when both rectal and vaginal swabs were collected for laboratory analysis. The simultaneous use of Todd-Hewitt broth and CNA plate also improved the yield of group B streptococcus.