Antibiotic usage and the incidence of resistance

Microbial Isolates and Association with Disease Severity and Quality of Life in Individuals with Hidradenitis Suppurativa: An Observational Study

Introduction

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by recurrent nodules, abscesses, and sinus tracts, resulting in scarring. Patients suffer significantly impacted quality of life (QoL), manifested by anxiety and depression. We describe microbial isolates identified from active sites in adults with HS, and explore associations between organisms isolated, disease severity, and QoL.

Methods

Observational study over 2 years. Assessment was made of disease severity using the Hurley staging score and of QoL scores, and subjective assessment. Wound swab samples were obtained from sites of active disease. Descriptive summary statistics and tests of significance were used to analyse the data.

Results

Two hundred and twelve patients participated, resulting in 352 episodes, and 501 lesion swab samples. 54% were female and 59% were obese, median age of 37 years. A lower proportion of Gram-negative organisms and more staphylococcal and streptococcal organisms were isolated from sites of disease in individuals with stage 3 disease compared to those with stage 1-2 disease (p = 0.001). We found no association between microbial isolation and QoL.

Discussion/Conclusions

Hurley stage 3 disease is associated with more infected lesions than Hurley stage 1-2 disease, but the QoL experienced by patients with HS is determined by factors other than infection.

Prevalence and Characterization of Integrons in Multidrug Resistant Acinetobacter baumannii in Eastern China: A Multiple-Hospital Study

Objective: The aim of this multiple-hospital study was to investigate the prevalence of integrons in multidrug-resistant Acinetobacter baumannii (MDRAB) in Eastern China, and characterize the integron-integrase genes, so as to provide evidence for the management and appropriate antibiotic use of MDRAB infections. Methods: A total of 425 clinical isolates of A. baumannii were collected from 16 tertiary hospitals in 11 cities of four provinces (Fujian, Jiangsu, Zhejiang and Shandong) from January 2009 to June 2012. The susceptibility of A. baumannii isolates to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, sulfamethoxazole/trimenthoprim, minocycline and imipenem was tested, and integrons and their gene cassettes were characterized in these isolates using PCR assay. In addition, integron-positive A. baumannii isolates were genotyped using pulsed-field gel electrophoresis (PFGE) assay, and intI1 gene cassette was sequenced. Results: intI1 gene was carried in 69.6% of total A. baumannii isolates, while intI2 and intI3 genes were not detected. The prevalence of resistance to ampicillin/sulbactam, piperacillin/tazobactam, ceftazidime, ceftriaxone, cefepime, aztreonam, imipenem, meropenem, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin and sulfamethoxazole/trimenthoprim was significantly higher in integron-positive A. baumannii isolates than in negative isolates (all p values <0.05), while no significant difference was observed in the prevalence of minocycline resistance (p > 0.05). PFGE assay revealed 27 PFGE genotypes and 4 predominant genotypes, P1, P4, P7 and P19. The PFGE genotype P1 contained 13 extensive-drug resistant and 89 non-extensive-drug resistant A. baumannii isolates, while the genotype P4 contained 34 extensive-drug resistant and 67 non-extensive-drug resistant isolates, appearing a significant antimicrobial resistance pattern (both p values <0.05). Sequencing analysis revealed two gene cassette assays of aacA4-catB8-aadA1 and dfrXII-orfF-aadA2 in MDRAB isolates. Conclusions: The results of this study demonstrate a high prevalence of class 1 integrons in MDRAB in Eastern China, and a greater prevalence of antimicrobial resistance in intI1 gene-positive MDRAB isolates than in negative isolates. Four predominant PFGE genotypes are identified in intI1 gene-positive MDRAB isolates, in which P4 is an epidemic PFGE genotype in Fujian Province, and it has a high proportion of extensive drug resistant A. baumannii. The gene cassette dfrXII-orfF-aadA2 is reported, for the first time, in A. baumannii strains isolated from Fujian Province, Eastern China.

The prevalence of antibiotic resistance in bacterial respiratory pathogens from Norway is low

OBJECTIVES

To determine the degree of bacterial susceptibility to the most commonly used drugs for respiratory infections in Norway, and to find if bacterial resistance is emerging.

METHODS

Clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae and group A streptococci from respiratory tract specimens and from the eye were collected from different parts of Norway during two study periods. During the first period (1993-1994), three laboratories, covering 15% of the Norwegian population, participated. During the second study period in 1997, five laboratories, covering 27% of the population, collected respiratory isolates. In total, 494 isolates of S. pneumoniae, 696 isolates of H. influenzae and 694 isolates of group A streptococci were included in the study. The study population comprised children and adults attending hospital and general practice. Bacterial susceptibility was determined by the E test, and breakpoints were according to the National Committee for Clinical Laboratory Standards (NCCLS).

RESULTS

The prevalence of bacterial resistance was low, and we observed no significant increase in bacterial resistance between the two study periods. In 1997, only 0.6% of pneumococci had decreased susceptibility to penicillin, 1.6% of group A streptococci were resistant to erythromycin, and 6.7% of all isolates of H. influenzae produced beta-lactamase.

CONCLUSIONS

The prevalence of antibiotic resistance in respiratory pathogens in Norway is low.

Minimizing potential resistance: a population dynamics view

I examine the results of studies that used mathematical models of the epidemiology and population genetics of antibiotic treatment and resistance in open communities and in hospitals to explore the following issues: the relationship between antibiotic consumption and the frequency of antibiotic resistance in bacterial populations in communities and in hospitals; methods of controlling the growth, dissemination, and persistence of antibiotic resistance in these settings; the extent to which resistance can be controlled; and the speed with which the effects of control measures will be realized. In open communities, it will take years or even decades to see substantial reductions in the frequency of antibiotic resistance solely as a result of more prudent (reduced) use of antibiotics. However, if we can restrict the input of resistant bacteria into hospitals, through the application of infection control and other measures, it should be possible to reduce the frequency of resistance and even eliminate resistant bacteria from these institutions in short order.