Traumatic myiasis by Wohlfahrtia magnifica in sheep flocks from southeastern Spain: prevalence and risk factors

Wohlfahrtia magnifica (Diptera: Sarcophagidae) is an obligate myiasis-causing fly of livestock that is widely distributed throughout the Mediterranean basin. A total of 73 683 sheep from 122 flocks in Albacete Province (southeastern [SE] Spain) were examined to detect active traumatic myiasis. The influence of several individual and flock factors on the prevalence was also assessed. The overall flock prevalence of traumatic myiasis was 95.9%, with an individual prevalence of 7.1%. Wohlfahrtia magnifica was identified in all of the positive animals except one that was infested by Lucilia sericata (Diptera: Calliphoridae). Adults of both genders showed a higher risk of infestation than juveniles, whereas males of all ages displayed an increased risk of infestation than females of all ages; the existence of a lambing building on the farm, poor husbandry facilities and the location area were also identified as risk factors. Prevalence was highest in the summer, and the fly season lasted from March to November. Genitalia were the main location of infestation in males (94.4%) and females (76.3%). Our results reveal that traumatic myiasis by W. magnifica is widespread in southeastern Spain, hence preventive measures minimizing the attractiveness of sheep to gravid flies are necessary to avoid health and welfare problems and significant production losses in sheep flocks.

Effect of a Chlorhexidine Mouthwash on the Risk of Postextraction Bacteremia

Objective.

To investigate the prevalence, duration, and etiology of bacteremia following dental extractions performed after a single administration of Chlorhexidine mouthwash.

Design and Setting.

A randomized, controlled trial performed in a university hospital.

Methods.

A series of 106 patients with mental and behavioral disabilities who underwent dental extractions under general anesthesia were randomly assigned to a control group or Chlorhexidine group. The exclusion criteria applied were use of antibiotics in the previous 3 months, use of oral antiseptics, any type of congenital or acquired immunodeficiency, and disease that predisposes the patient to infections or bleeding. The Chlorhexidine group had 0.2% Chlorhexidine mouthwash administered for 30 seconds before any dental manipulation. Blood samples were collected at baseline, 30 seconds, 15 minutes, and 1 hour after the dental extractions. Subculture and further identification of the isolated bacteria were performed by conventional microbiological techniques.

Results.

The prevalence of bacteremia after dental extraction in the control and Chlorhexidine groups were 96% and 79%, respectively, at 30 seconds (P = .008), 64% and 30% at 15 minutes (P <.001), and 20% and 2% at 1 hour (P = .005). The most frequently identified bacteria were Streptococcus species in both the control and Chlorhexidine groups (64% and 68%, respectively), particularly viridans group streptococci.

Conclusion.

We recommend the routine use of a 0.2% Chlorhexidine mouthwash before dental extractions to reduce the risk of postextraction bacteremia.

Pharmacokinetics of enrofloxacin after single intravenous administration in sheep

The disposition of enrofloxacin in sheep was investigated after single-dose intravenous administration of 2.5 mg/kg body weight. Blood samples were drawn from the jugular vein at predetermined times after drug administration. Plasma concentrations of enrofloxacin and its active metabolite ciprofloxacin were simultaneously determined by reverse-phase high performance liquid chromatography. The data collected were subjected to non-compartmental and compartmental kinetic analysis. Statistical model theory was used to determine non-compartmental pharmacokinetic parameters. Disposition of enrofloxacin was described by a three-compartment open model with elimination from the central compartment following intravascular administration. The elimination half-life, the volume of distribution, and the area under the concentration vs time curve (AUC) were 4.31 h, 1.10 l/kg and 9.24 microg x h/ml, respectively. Enrofloxacin was metabolised to ciprofloxacin and the ratio between the AUCs of ciprofloxacin and enrofloxacin was 0.26 after intravenous administration. With predictive models of efficacy (maximum plasma concentrations/minimum inhibitory concentrations [Cmax/MIC] and AUC/MIC ratios in plasma) for most of the sheep pathogen microorganisms, enrofloxacin produced scores higher than 15 and 50, respectively. After intravenous administration atthe dose of 2.5 mg/kg, enrofloxacin achieved concentrations several times above the MIC for major pathogen bacteria in plasma, and it may prove useful in the treatment of infectious diseases caused by sensitive pathogens in sheep.

[Isolation, characterization and typing of Escherichia coil 0157:H7 strains from beef products and milk]

Shiga toxin (Stx)-producing Escherichia coli (STEC) is an emergent pathogen associated with foodborne diseases, especially foodstuffs of animal origin. A total of 250 beef samples (ground beef and hamburgers) obtained from retail outlets in Santa Fe and Santo Tomé cities, and 150 milk samples from bulk tank milk from dairy barns of the region were analyzed by selective enrichment and immunomagnetic separation. Escherichia coli O157:H7 stx2, eae and ehxA positive strains were isolated from three (1.2%) beef samples. The strains could be differentiated by pulsed-field gel electrophoresis, phagetyping and genotyping of stx. The milk samples were negative for STEC O157. These findings confirm the role of food of animal origin in the epidemiology of E. coli O157:H7 - associated diseases.

In vitro activity of moxifloxacin compared to other antimicrobials against streptococci isolated from iatrogenic oral bacteremia in Spain

BACKGROUND/AIMS

Systemic dissemination of oral bacteria to distant body sites may be the cause of focal infections. The unsuitable use and overexposure to antimicrobial therapy in clinical dental practice may contribute to the worldwide problem of antimicrobial resistance. The aim of this study was to determine the susceptibilities of streptococci isolated from the bloodstream after dental extractions against penicillin, ampicillin, amoxicillin, erythromycin, clindamycin, and a new fluoroquinolone, moxifloxacin.

PATIENTS AND METHODS

Eighty-four patients who required dental extractions were studied. Venous blood samples were collected from each patient at baseline (before dental manipulation) and 30 s after dental extractions. The samples were processed in the Bactec 9240. The isolated bacteria were identified by conventional microbiological techniques. The antimicrobial susceptibility of 81 streptococci was determined by the E-test method. The NCCLS performance standards were followed.

RESULTS

88.9-92.5% of the streptococci were sensitive to beta-lactam agents tested with a minimum inhibitory concentration (MIC)(90s) ranging from 0.094 to 0.19 mg/l. The resistance to erythromycin and clindamycin was 40.8% (MIC(90HR) = 256 mg/l) and 21% (MIC(90HR) = 256 mg/l), respectively. The MIC(90) to moxifloxacin was 0.125 mg/l.

CONCLUSION

Most of the streptococci isolated from the bloodstream after dental extractions were susceptible in vitro to penicillin, ampicillin, and amoxicillin. The high percentage of streptococci resistant to erythromycin and clindamycin could restrict their usefulness as prophylactic drugs. All the isolates showed a low MIC of moxifloxacin in vitro, making it a promising antimicrobial alternative for the prevention of streptococcal focal infections associated with certain dental manipulations, when the administration of beta-lactam agents is not indicated.

Isolation and characterisation of Shiga toxin-producing Escherichia coli O157:H7 from calves in Argentina

Four hundred and twenty-two calves were examined for intestinal carriage of Shiga toxin-producing Escherichia coli O157:H7 using conventional plating. Two (0.5%) E. coli O157 were recovered. They were compared with 96 Argentine strains of different origin by pulsed-field gel electrophoresis, phage typing and PCR-RFLP of stx2 genes. One strain isolated from a calf, was closely related with 18 strains of clinical origin.

Ocular echography in the prognosis of vitreous haemorrhage in type II diabetes mellitus

PURPOSE

In this study, we have attempted to demonstrate the presence of various echographic parameters which could be associated with a non-spontaneous resorption of vitreous haemorrhage in type II diabetes mellitus and correlate these parameters with clinical outcome.

SUBJECTS AND METHODS

We studied 297 eyes of 257 patients with diabetic retinopathy and vitreous haemorrhage without tractional macular retinal detachment ophthalmoscopically and echographically. Of the total eyes studied, a 3-month follow-up visit (including ultrasound) was available in 208 eyes. We retrospectively reviewed the medical records of each patient.

RESULTS

The echographic parameters associated with non-resorption of the vitreous haemorrhage were: extramacular tractional retinal detachment, fibrovascular membranes and location of the haemorrhage within the subhyaloidal space (in contrast to within the intragel space). In addition, the duration of the vitreous haemorrhage and the presence of panretinal laser photocoagulation at the time of presentation with a vitreous haemorrhage influenced the resolution of the vitreous haemorrhage. We were also able to construct a logarithmic function that could be used to predict the prognosis of a vitreous haemorrhage in type II diabetes mellitus.

CONCLUSIONS

When employed to evaluate vitreous haemorrhages in non-insulin-dependent diabetes mellitus, ocular ultrasound can provide useful prognostic information regarding the lack of resorption of vitreous haemorrhages in type II diabetics.