Yet Another Doctor Blog On The Internet



Rickettsial infections are re-emerging in the Indian subcontinent, especially among children. Understanding geographical and clinical epidemiology will facilitate early diagnosis and management.

The use of antimicrobials for the control of infectious disease has increased in recent decades. Understanding trends in antimicrobial resistance provides clues about the relationship between antimicrobial use and the emergence of resistance. We examined the resistance of 540 Escherichia coli isolates to 19 antimicrobials that represent 11 classes of antimicrobial agents. The isolates were collected from chickens between 1993 and 2013 in China. Overall, >96.7% of the isolates were resistant to at least one of the tested compounds, and 87.2% of them displayed multidrug resistance (MDR) representing five to six antimicrobial classes. A high proportion of E. coli isolates were resistant to tetracycline (90.6%), nalidixic acid (80.6%), ampicillin (77.2%), trimethoprim-sulfamethoxazole (76.9%), and streptomycin (72.8%). Only 3.0% of the isolates were resistant to nitrofurantoin, and none was resistant to meropenem. Resistance to amikacin, ampicillin, aztreonam, ceftazidime, cefotaxime, cephalothin, chloramphenicol, ciprofloxacin, fosfomycin, levofloxacin, norfloxacin, nalidixic acid, piperacillin, and trimethoprim-sulfamethoxazole significantly increased from 1993 to 2013 (P <0.01). There was an increasing trend in MDR over the 20 year period.

One hundred twenty-two patients were included: 14 received one drop of chloramphenicol suspension; 12 one application of chloramphenicol gel; 11 one drop of netilmicin suspension; 13 one drop of tobramycin suspension; 37 repeated instillations of chloramphenicol suspension every 10 min for a total of four drops; and 35 repeated instillations of chloramphenicol gel every 10 min for a total of four drops. Samples were taken immediately before surgery from the anterior chamber in order to determine the antibiotic by means of high-performance liquid chromatography. Samples were taken 45-190 min after the eye drops were instilled.

Aerococcus viridans, the causative agent of the disease gaffkemia, was a major cause of mortality in lobsters (Homarus americanus) held in tidal impoundments during the 1970s and 1980s. Despite reports of an increase in the mortality of lobsters during impoundment, and the widespread prophylactic use of oxytetracycline against A. viridans, this bacterium has not been detected in active disease surveillance of the Maine postcapture lobster population. However, Photobacterium indicum may be an emerging opportunistic pathogen of stressed lobsters. An acute toxicity trial was conducted as a rapid screening procedure for the potential future use of the antibiotic florfenicol. Based on the results of this experiment, florfenicol appears to be well tolerated in adult H. americanus by intrapericardial injection at the 10-100 mg/kg dose. Oxytetracycline dihydrate is contraindicated by intrapericardial injection at the 10-100 mg/kg dose.

A random sampling of slaughter animals was carried out.

The single-dose disposition kinetics of florfenicol was determined in healthy, non-lactating Egyptian goats, after its intravenous (i.v.) and intramuscular (i.m.) administration at 20 mg kg-1 b.wt. Drug concentrations in serum and urine were determined using microbiological assay method and data was subjected to a kinetic analysis. Florfenicol concentrations in serum decreased in a bi-exponential manner after intravenous administration with distribution (t1/2 alpha) and elimination (t1/2 beta) half-lives of 10.256 +/- 0.938 and 56.237 +/- 3.102 minute, respectively. The steady-state volume of distribution (Vdss) and total body clearance (Cltot) were 3.413 +/- 0.304 l kg-1 and 3.306 +/- 0.333 l kg h-1. After intramuscular administration, the peak serum concentration (Cmax) was 0.859 +/- 0.025 micrograms ml-1, achieved at (Tmax) 1.220 + 0.045 h. Florfenicol was detected in urine up to 24 and 96 hour after i.v. and i.m. administration, respectively. The extent of the protein binding and systemic bioavailability of florfenicol were 22.45 +/- 1.727% and 65.718 +/- 3.372%, respectively.

A total of 160 samples of poultry (80), pork (40), and beef (40) preparations (red sausages, white sausages, hamburgers, meatballs, nuggets, minced meat, escalope, and crepes) were tested in northwestern Spain to determine the prevalence of vancomycin-resistant enterococci (VRE). VRE were detected in 38 (23.8%) samples (37.5% of poultry, 15.0% of pork, and 5.0% of beef samples). One strain per food sample was further characterized. Isolates were identified as Enterococcus faecium (14 strains), E. durans (10), E. hirae (7), E. gallinarum (5), and E. casseliflavus-E. flavescens (2). All strains showed resistance or intermediate susceptibility to three or more antimicrobials of clinical significance, in addition to vancomycin. High rates of resistance or intermediate susceptibility were observed for teicoplanin (81.6% of isolates), chloramphenicol (81.6%), erythromycin (100%), quinupristin-dalfopristin (89.5%), and ciprofloxacin (81.6%). A moderate rate of resistance or intermediate susceptibility emerged for ampicillin (34.2%) and tetracycline (36.8%). Genes encoding antimicrobial resistance and virulence were studied by PCR. The vanA, vanB, vanC-1, and vanC-2/3 genes were identified in 27, 1, 5, and 2 isolates, respectively. Other resistance genes or transposon sequences found were tet(L), tet(M), Tn5397 (tetracycline), erm(A), erm(B) (erythromycin), vat(D), and vat(E) (quinupristin-dalfopristin). Most isolates were free of virulence determinants (agg, hyl, and efaAfm genes were detected in one, one, and five strains, respectively). Strains were classified as not biofilm producers (crystal violet assay; 4 isolates) or weak biofilm producers (34 isolates). Cluster analysis (EcoRI ribotyping) suggested a strong genetic relationship among isolates from different types of meat preparations, animal species, and retail outlets. Meat preparations might play a role in the spread through the food chain of VRE with several resistance and virulence genes.