Clinical spectrum of ventilator-associated pneumonia caused by methicillin-sensitiveStaphylococcus aureus

The incidence of tracheal colonization and its association with ventilator-associated pneumonia caused by methicillin-sensitiveStaphylococcus aureus (MSSA) was studied prospectively in 530 consecutively admitted mechanically ventilated patients in a general intensive care unit. Furthermore, the clinical spectrum, outcome, and microbiological results of 27 cases of staphylococcal ventilator-associated pneumonia (SVAP) were examined. Ventilator-associated pneumonia was diagnosed by protected specimen brush and/or bronchoalveolar lavage. On admission, 7% of the patients were colonized with MSSA in the trachea. Acquired tracheal colonization was demonstrated in 10% of the patients and occurred less frequently in patients with a hospital stay of > 48 h before ICU admission compared to patients admitted directly to the ICU (6% vs. 15%, p<0.001). Moreover, colonization was acquired more frequently among trauma and neurological/neurosurgical patients (22%) as compared to surgical and medical patients (7%) (p<0.0001). Twenty-one patients (4%) developed SVAP, the incidence being higher in patients colonized in the trachea with MSSA than in those not colonized (21 % vs. 1 %, p<0.00001). Staphylococcal ventilator-associated pneumonia developed more often in trauma and neurological/neurosurgical patients as compared to surgical and medical patients (8% vs. 3%, p<0.05). Moreover, patients with a hospital stay of < 48 h before admission to the ICU had a higher incidence of SVAP as compared to those with a longer hospital stay before ICU admission (7% vs. 2%, p<0.01). Crude infection-related mortality was 26%. Preceding colonization with MSSA in the trachea appears to be an important risk factor for the development of SVAP, and patients with a short duration of hospitalization before intensive care unit admission have the highest incidence of ventilator-associated pneumonia caused by MSSA.     

Repetitive conundrums of centromere structure and function

In the last few years, a paradox has emerged regarding the relationship of centromere structure and its function. Most centromeric DNAs analyzed to date are composed of a remarkably complex array of repeat structures. In contrast, recent analyses of neocentromeric DNA reveal that repetitive DNA is not a prerequisite for centromere activity. The ubiquity of repetitive sequences among diverse species at sites of primary constriction argues that there is a strong evolutionary link between centromere structure and function. Dynamic mutational processes resulting in amplification, deletion and transposition of repetitive sequences appear to occur frequently in such regions, resulting in considerable interspecific diversity in structure and sequence. One possible solution to this conundrum may be that the rapid accumulation of repetitive sequences within centromeric and pericentromeric DNA is a consequence of functionally active centromeres. Emerging repetitive structures at centromeric sites may be an important byproduct of a functional centromere which ensures that site as an evolutionarily favored position in subsequent meiotic and mitotic lineages. The recent identification of large gene duplications in the vicinity of centromeres may be another example of the enhanced mutational lability of such regions of the genome.      

Probiotics versus antibiotic decontamination of the digestive tract: infection and mortality

Purpose  

Selective decontamination of the digestive tract (SDD) has been shown to decrease the infection rate and mortality in intensive care units (ICUs); Lactobacillus plantarum 299/299v plus fibre (LAB) has been used for infection prevention and does not harbour the potential disadvantages of antibiotics. The objective was to assess whether LAB is not inferior to SDD in infection prevention.     

Socio—cultural factors influencing insecticide treated bed net utilization in a malaria endemic city in north—central Nigeria

ObjectiveTo ascertain the socio-cultural factors influencing the rate of utilization of insecticide treated bed nets (ITNs) in a malaria endemic city of Makurdi, north central Nigeria.MethodsThe study was cross-sectional in nature using systematic sampling method to identify households. Both quantitative and qualitative data was generated from adult women using structured and semi structured questionnaires, and focused group discussions (FGDs) to obtain information on rate and patterns of utilization of ITNs. Information such as age, educational level, marital status, awareness or otherwise of the existence of malaria, and factors influencing rate of ownership and utilization of ITNs were obtained. FGDs were used to obtain qualitative information on rate of utilization of ITNs not captured in the questionnaires. Data obtained was analysed using Epi Info 6 statistical software.ResultsAmong the respondents interviewed, 97.0% (2 013/2 075) were aware of existence of malaria and 87.0% of these (1 751/2 013) would associate it with mosquitoes. The rate of ownership of any bed net, ITNs and untreated bed nets (UTNs) was 25.1%, 17.0% and 8.3%, respectively. Utilization of ITNs among children was 30.0% (112/373) and UTNs 12.9% (48/373). Positive contributors to ITNs utilization were literacy, enhanced economy, experience of marriage, and being gainfully employed (P<0.05); while negative contributors were ignorance, poverty and some cultural beliefs and values.ConclusionsA more synchronized advocacy should be carried out on the potential benefits of ITNs utilization and sustained. Also ITNs should be made available to the people of the community at minimal or no cost.     

A study of anemia in women with asymptomatic malaria parasitaemia at their first antenatal care visit at the General Hospital,Ikot Ekpene,Akwa Ibom State,Nigeria

ObjectiveTo assess the prevalence of anemia and asymptomatia malaria parasitemia and the effect of prior antimalarials therapy on the parasite density in pregnant women at their first antenatal visit at the secondary level health care facility in Nigeria.MethodsThis cross sectional observational study was carried out in the antenatal clinic of General Hospital, Ikot Ekpene, Akwa Ibom State, Nigeria for 3 months period (1^st June to 31^st August, 2009). Five hundred and fourteen women attending their first antenatal registration visits in the hospital were recruited in the study. Socio-demographic information was obtained using pre-tested questionnaires. The malaria parasite was obtained by examining thick and thin blood films prepared on 2 glass slides while the hematocrit was obtained through 2 capillary tubes read by a Hawksleys microhematocrit reader.ResultsA total of 514 pregnant women participated in the study with a mean maternal age of 21.4 years and a mean gestational age at booking of 18.3 weeks. The primigravid women booked at significantly lower gestational age than multigravidae (16.2 weeks vs 21.6 weeks). Most of the women (59.3%) were anemic, out of which 60.4% were primigravida. More than half of the women had moderate to high parasite density and only 6.8% had no malaria parasitemia. All patients with severe anemia were parasitemic. Out of the 479 (93.2%) women with parasitemia, a third had taken antimalarial drugs. A majority (60.3%) of those without prior antimalarial drugs had moderate to high density parasitemia.ConclusionsThis study shows high prevalence of anemia in women with asymptomatic malarial parasitemia, particularly the primigravida. The severity of anemia is directly related to the density of malaria parasitemia. Those with effective antimalarial therapy appear to have low density parasitemia and therefore mild anemia. Routine screening for anemia and malaria parasites at booking, prompt parasite clearance and correction of anemia would reduce the associated maternal and perinatal complications.     

Staphylococcus aureus carriage among GPs in the Netherlands

Background

The extent to which GPs serve as a reservoir for antibiotic-resistant Staphylococcus aureus is unknown and not well studied.

Aim

To determine the prevalence of nasal S. aureus carriage among GPs in the Netherlands, as well as the antimicrobial resistance and the genotypes of isolated S. aureus.

Design of study

Observational, point-prevalence, and cross-sectional study.

Setting

GPs attending the annual conference of the Dutch College of General Practitioners in 2006.

Method

Nasal swabs were randomly taken from 395 GPs and analysed for the presence of S. aureus. Antimicrobial susceptibility was determined by a microbroth dilution method and the genotypes by spa typing, which was associated with multilocus sequence typing.

Results

Of the GPs, 129/395 (33%; 95% confidence interval [CI] = 28 to 37%) were carriers of S. aureus. No meticillin-resistant S. aureus (MRSA) was found. Resistance was observed to penicillin (71%; 95% CI = 63 to 79%), fusidic acid (7%; 95% CI = 3 to 13%), and clarithromycin (6%; 95% CI = 3 to 12%). In 72% of the isolates, an MRSA-related genotype of S. aureus was found.

Conclusion

The low antibiotic resistance found among S. aureus of GPs suggests that GPs are not a reservoir of antibiotic-resistant S. aureus strains. The relatively high resistance to fusidic acid, which has not previously been described in the Netherlands and is mostly because of antibiotic use, suggests that patients infect GPs and not the other way round. GPs may be at risk for nasal carriage of S. aureus with an MRSA-related genotype.