Changes In Antibiotic Sensitivity Research Articles

Nutrient conditions affect antimicrobial pharmacodynamics in Pseudomonas aeruginosa.

The infectious microenvironment in chronic respiratory tract infections is characterized by substantial variability in nutrient conditions, which may impact colonization and treatment response of pathogens. Metabolic adaptation of the cystic fibrosis (CF)-associated pathogen Pseudomonas aeruginosa has been shown to lead to changes in antibiotic sensitivity. The impact of specific nutrients on the response to antibiotics is, however, poorly characterized. Here, we investigated how different carbon sources impact the antimicrobial pharmacodynamic responses in P. aeruginosa. We evaluated the effect of six antibiotics (aztreonam, ceftazidime, ciprofloxacin, colistin, imipenem, and tobramycin) on P. aeruginosa cultured in a basal medium enriched for seven different carbon sources (alanine, arginine, aspartate, glucose, glutamate, lactate, and proline). Pharmacodynamic responses were characterized by measuring time-kill profiles for a bioluminescent P. aeruginosa PAO1 Xen41 strain. We show that single-nutrient modifications minimally affected bacterial growth rate. For specific nutrient-antibiotic combinations, we find relevant alterations in antibiotic sensitivity (i.e., EC50) and the maximum drug effect (Emax), in particular for ciprofloxacin, colistin, imipenem, and tobramycin. The most pronounced effect was observed for tobramycin, where glucose was found to reduce the EC50 (0.5-fold), whereas lactate-enriched conditions led to a 4.3-fold increase in EC50. Using pharmacokinetic-pharmacodynamic simulations, we illustrate that the magnitude of the nutrient-driven pharmacodynamic changes impact treatment for clinical dosing strategies of tobramycin. In summary, this study underscores the impact of nutrient composition on antimicrobial pharmacodynamics, which could potentially contribute to observed variability of antimicrobial treatment responses in CF patients.IMPORTANCEChronic respiratory tract infections in cystic fibrosis patients present significant challenges for antibiotic treatment due to the complexity of the respiratory environment. This study investigated how variations in nutrient levels, altered during chronic infections, affect pathogen response to antibiotics in an experimental setting. By simulating different nutrient conditions, we aimed to uncover interactions between nutrient availability and antibiotic sensitivity. Our findings provide critical insights that could lead to more effective treatment strategies for managing chronic respiratory tract infections in cystic fibrosis patients while also guiding future research in improving treatment methodologies.

Skull Base Osteomyelitis- Marauders of the Skull.

Skull base osteomyelitis is a vicious infection of temporal bone associated with very high morbidity and mortality. But few studies have been undertaken recently for eliciting its increasing incidence. Hence this study aims to describe the clinical profile of skull base osteomyelitis and changes noted in the post-covid period, and encourage a uniform treatment policy globally. This descriptive study was conducted among 140 patients diagnosed with skull base osteomyelitis. Data was collected using semi-structured proforma, HRCT temporal bone findings, microbiological reports, histopathology of granulation tissue, ESR and House-Brackmann grading. Male patients in 61-70 age group were most commonly affected and all patients had uncontrolled diabetes mellitus, usually presenting with nocturnal otalgia, ear canal granulation and cranial nerve palsy. Pseudomonas aeruginosa was the most common isolate followed by Staphylococcus aureus. Among fungal pathogens, candida albicans were the most common. 29.3% patients had extensive disease according to Thakar et al. staging and on follow up, 43.75% patients showed a satisfactory response. Coronary artery disease and cerebrovascular accidents were the leading cause of death. More atypical organisms, extensive disease and changes in antibiotic sensitivity were noted in the post-covid period. Prolonged treatment with culture sensitive antibiotic is the main stay of treatment. A uniform treatment guideline is needed for proper management of such patients. Level of Evidence 4.

Exposure to a Manuka Honey Wound Gel Is Associated With Changes in Bacterial Virulence and Antimicrobial Susceptibility.

The use of manuka honey for the topical treatment of wounds has increased worldwide owing to its broad spectrum of activity towards bacteria in both planktonic and biofilm growth modes. Despite this, the potential consequences of bacterial exposure to manuka honey, as may occur during the treatment of chronic wounds, are not fully understood. Here, we describe changes in antimicrobial susceptibility and virulence in a panel of bacteria, including wound isolates, following repeated exposure (ten passages) to sub-inhibitory concentrations of a manuka honey based wound gel. Changes in antibiotic sensitivity above 4-fold were predominantly related to increased vancomycin sensitivity in the staphylococci. Interestingly, Staphylococcus epidermidis displayed phenotypic resistance to erythromycin following passaging, with susceptibility profiles returning to baseline in the absence of further honey exposure. Changes in susceptibility to the tested wound gel were moderate (≤ 1-fold) when compared to the respective parent strain. In sessile communities, increased biofilm eradication concentrations over 4-fold occurred in a wound isolate of Pseudomonas aeruginosa (WIBG 2.2) as evidenced by a 7-fold reduction in gentamicin sensitivity following passaging. With regards to pathogenesis, 4/8 bacteria exhibited enhanced virulence following honey wound gel exposure. In the pseudomonads and S. epidermidis, this occurred in conjunction with increased haemolysis and biofilm formation, whilst P. aeruginosa also exhibited increased pyocyanin production. Where virulence attenuation was noted in a passaged wound isolate of S. aureus (WIBG 1.6), this was concomitant to delayed coagulation and reduced haemolytic potential. Overall, passaging in the presence of a manuka honey wound gel led to changes in antimicrobial sensitivity and virulence that varied between test bacteria.

Bactericidal effects of in vitro 405 nm, 530 nm and 650 nm laser irradiation on methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Mycobacterium fortuitum

Laser irradiation (LI) is an emerging antimicrobial strategy that may reduce public health reliance on antibiotics but previous studies reported results based on one wavelength-duration LI, typically on one bacterial species using solid culture. This study aimed to evaluate the effect of increasing duration of 405 nm, 532 nm and 650 nm LI on methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Mycobacterium fortuitum in liquid culture. Bacterial cultures of 1000 CFU/ml irradiated with 405 nm, 532 nm and 650 nm (200 mW) laser at 1, 2, 5 and 10 min were subcultured on nutrient agar; colony counts pre/post-LI were recorded and survival calculated. Antimicrobial sensitivity and cell morphology pre/post-LI were compared using scanning electron microscopy (SEM) and disc diffusion, respectively. The 405 nm (blue) LI had the highest bactericidal effect (0–6% survival) on all test bacteria compared to 532 nm (green) (12–49% survival) and 650 nm (red) (33–94% survival) LI. An inverse relationship between LI duration and survival was observed, except in 650 nm LI of P. aeruginosa, whereby survival increased with increasing duration. No change in antibiotic sensitivity was observed for subcultured bacterial colonies post-10 min LI. Although SEM micrographs of bacteria 10 minutes post-405 nm LI showed appreciable cell morphological changes, no significant cellular damage was observed. These encouraging results confirm bactericidal effects of 405 nm LI on bacteria such as P. aeruginosa and further expand findings on 532 nm and 650 nm LI on bacterial survival, highlighting the potential of LI as novel antimicrobial strategies on opportunistic pathogens such as MRSA, P. aeruginosa and M. fortuitum.

Evaluation of Antibiotics Effectiveness Against Vibrio Cholerae under the Conditions of Complex Biofilm Formation

The effectiveness of 9 antibiotics against mono- and polymicrobial biofilms formed by Vibrio cholerae O1 strains was studied in vitro on fragments of chitinous exoskeleton of broad- fingered crayfish Astacus astacus in monoculture and together with oppor­tunistic bacteria Klebsiella spp. and non-O1/non-O139 V.cholerae. An increase in the antibiotic resistance of monomicrobial biofilms compared with planktonic bacteria was observed. Resistance of the polymicrobial biofilm bacteria to most antibacteri­al drugs corresponded to the resistance of the most stable strain in the monomicrobial biofilm. An increase in resistance to two and three drugs was observed in biofilms formed by classical toxigenic strains together with non-O1/non-O139 V.cholerae, while in biofilms formed together with Klebsiella spp. — to one antibacterial drug. Changes in antibiotic sensitivity during the interaction between bacteria in polymicrobial biofilm should be taken into account when developing tactics for prevention and treatment of infections.

Influence of antibiotics and silver nanoparticles on the change of sensitivity of <i>E. coli </i>to antibacterial drugs

Research has been conducted to evaluate the effect of antibiotics and silver nanoparticles in combination with antibiotics on the change in antibiotic sensitivity to antibacterial drugs of E. coli ATCC 25922 reference strain and its isolate. Nanoparticles obtained by electron beam treatment of aqueous solution containing water-soluble stabilizing polymer and water-soluble silver salt were used in the experiment. During the treatment a beam of accelerated electrons obtained on the installation of a linear accelerator of the ILU-10 type passed through a solution with a working dose of 5–30 kGy ranging in size from 20 to 60 nm. Sensitivity of microorganisms of E. coli ATCC 25922 reference strain and its isolate obtained from cow endometritis to antibacterial substances and their combinations was determined from dilution with a minimum bacteriostatic concentration. The dilution in the amount of 0.2 ml was added to meat-and-peptone agar and the antibiotic sensitivity of microorganisms was determined by the disk diffusion method. Sensitivity to 24 types of antibacterial drugs was tested. Cultivation of E. coli ATCC 25922 with AgNPs in combination with one of the antibiotics (azitronite, amoxicillin, enroflox, ceftiofur, tylosin, cobactan, oxytetracycline) contributed to an increase in the number of drugs (from 14.3 to 57.1%), to which the microorganism was sensitive. Cultivation of the E. coli isolate with 5 (62.5%) of the studied antibiotics led to an increase in resistance from 1 (5.5%) to 3 (16.7%) antibacterial agents. AgNPs in combination with antibiotics azitronite, amoxicillin, enroflox, ceftiofur, tylosin, cobactan, gentamicin, oxytetracycline contributed to a decrease in the resistance of E. coli ATCC 25922 (from 15.4 to 46.1%) and E. coli field isolate (from 16.7 to 37.7%) to antibacterial drugs. The pronounced ability of AgNPs to increase antibiotic sensitivity was established. This was confirmed by the joint cultivation of antibiotics and AgNPs with E. coli ATCC 25922 and field isolate of E. coli, causing an increase in sensitivity and high sensitivity to antibacterial drugs, which was previously absent. The study confirmed the results of research on the ability of nanoparticles of metals of the transition group to affect the sensitivity of microorganisms to antibacterial agents and to restore it.

Microbiological Isolates and Antibiotic Susceptibilities in Cases of Posttraumatic Endophthalmitis: A 15-Year Review.

Purpose The objective of this study was to evaluate the microbiological spectrum and antibiotic susceptibilities of isolates in posttraumatic endophthalmitis over a 15-year period. Methods A retrospective study of 3,163 posttraumatic endophthalmitis cases was conducted between July 2004 and July 2019. The outcome measures included the microbiological spectrum and antibiotic susceptibilities. Chi-squared tests were conducted to detect trends in changes in antibiotic sensitivity over the 15-year period. P values of <0.05 were considered statistically significant. Results Of the 3,163 cases of posttraumatic endophthalmitis, 1,003 culture-positive isolates were identified. Among these, there were 848 (84.5%) Gram-positive isolates, 109 (10.9%) Gram-negative isolates, and 46 (4.6%) fungal isolates. The most common isolates were Staphylococcal species. There was a significant increase in the percentage of fungal isolates over the 15-year period (P=0.02). Gram-positive organisms showed the greatest level of susceptibility to vancomycin (99.6%). The susceptibilities of the 109 Gram-negative isolated organisms were as follows: levofloxacin (95.8%), meropenem (95.7%), ciprofloxacin (93.5%), tobramycin (90.8%), imipenem (88.9%), trimethoprim-sulfamethoxazole (TMP-SMX) (87.7%), ertapenem (80%), and ceftazidime (79.1%). The susceptibility of Gram-positive organisms to several antibiotics, including levofloxacin (P=0.004), ciprofloxacin (P < 0.001), and chloramphenicol (P=0.001) decreased over time, whereas the susceptibility to TMP-SMX increased over time (P < 0.001). The susceptibility of Gram-negative bacilli to ceftazidime decreased over time (P=0.03). Conclusions Over the 15-year study period, most isolates were Gram-positive cocci, especially coagulase-negative staphylococci (CNS). Vancomycin seemed to be the most effective antibiotic for Gram-positive bacteria. Gram-negative bacteria appeared to be most susceptible to fluoroquinolones. A number of antibiotics showed an increasing trend of microbial resistance.

Evaluation of Short-Term Exposure to 2.4 GHz Radiofrequency Radiation Emitted from Wi-Fi Routers on the Antimicrobial Susceptibility of Pseudomonas aeruginosa and Staphylococcus aureus

Background: Overuse of antibiotics is a cause of bacterial resistance. It is known that electromagnetic waves emitted from electrical devices can cause changes in biological systems. This study aimed at evaluating the effects of short-term exposure to electromagnetic fields emitted from common Wi-Fi routers on changes in antibiotic sensitivity to opportunistic pathogenic bacteria. Materials and Methods: Standard strains of bacteria were prepared in this study. Antibiotic susceptibility test, based on the Kirby-Bauer disk diffusion method, was carried out in Mueller-Hinton agar plates. Two different antibiotic susceptibility tests for Staphylococcus aureus and Pseudomonas aeruginosa were conducted after exposure to 2.4-GHz radiofrequency radiation. The control group was not exposed to radiation. Results: Our findings revealed that by increasing the duration of exposure to electromagnetic waves at a frequency of 2.4 GHz, bacterial resistance increased against S. aureus and P. aeruginosa, especially after 24 hours (P&lt;0.05). Conclusion: The use of electromagnetic waves with a frequency of 2.4 GHz can be a suitable method for infection control and treatment. [GMJ.2020;9:e1580]

Evaluation of Short-Term Exposure to 2.4 GHz Radiofrequency Radiation Emitted from Wi-Fi Routers on the Antimicrobial Susceptibility of Pseudomonas aeruginosa and Staphylococcus aureus.

Background: Overuse of antibiotics is a cause of bacterial resistance. It is known that electromagnetic waves emitted from electrical devices can cause changes in biological systems. This study aimed at evaluating the effects of short-term exposure to electromagnetic fields emitted from common Wi-Fi routers on changes in antibiotic sensitivity to opportunistic pathogenic bacteria. Materials and Methods: Standard strains of bacteria were prepared in this study. Antibiotic susceptibility test, based on the Kirby-Bauer disk diffusion method, was carried out in Mueller-Hinton agar plates. Two different antibiotic susceptibility tests for Staphylococcus aureus and Pseudomonas aeruginosa were conducted after exposure to 2.4-GHz radiofrequency radiation. The control group was not exposed to radiation. Results: Our findings revealed that by increasing the duration of exposure to electromagnetic waves at a frequency of 2.4 GHz, bacterial resistance increased against S. aureus and P. aeruginosa, especially after 24 hours (P<0.05). Conclusion: The use of electromagnetic waves with a frequency of 2.4 GHz can be a suitable method for infection control and treatment.

The evolution of the microbiological landscape and antibiotic sensitivity in ICD patients

Purpose of work . Reducing antibiotic resistance by introducing the proposed complex of prevention and control of infection in ICU. Materials and research methods. The work includes an analysis of bacteriological studies of 1111 patients undergoing treatment at the ICU of the Ternopil University Hospital for the period from January to August 2015 (group I) and for the same period in 2018 (group II). The set of innovations included: measures to prevent the spread of antibiotic-resistant pathogens and the rational use of antibiotics. Results and discussion . The largest changes in antibiotic sensitivity were found for imipinem. The growth of the latter by 60% (p≤0.05) was revealed, which amounted to 100% sensitivity of clinical isolates of Ps. Aeruginosa to imipinem. The preservation of the multi-resistance of the clinical isolates of Klebsiella pneumoniae in patients of group I and II, and a decrease in the number of seeding by 39%, is of great prognostic value. Conclusions . The range of proposed measures included the distribution of patients into blocks depending on the risk of developing infectious complications, monitoring antibiotic prescribing, observance of sanitary and hygienic standards by ICD personnel, the use of sodium hypochlorite, and the number of pathogenic isolates and the level of antibiotic resistance to certain groups of antibacterial drugs.

Hallazgos recientes de helicobacter pylori resistente a antibióticos en la República Dominicana

Introducción: Helicobacter pylori ha sido designado como responsable de múltiples trastornos del tracto gastroin-testinal, por lo que el diagnóstico y erradicación de la mucosa gástrica constituye una prioridad en el cuidado del paciente ulceroso. La presencia de resistencia a los antibióticos utilizados en su erradicación representa un problema importante.&#x0D; Método: propusimos hacer una investigación, de carácter prospectivo y experimental, para determinar la sensibilidad in vitro de la Helicobacter pylori (H. pylori) a una selección de antibióticos utilizados en los esquemas de erradicación de bacterias.&#x0D; Resultados: ciprofloxacino, levofloxacino, fosfomicina, fueron los antibióticos más altamente sensibles in vitro, estadísticamente significativos para el H pylori. La amoxi-cilina y la claritromicina fueron los menos sensibles.&#x0D; Conclusión: estos resultados muestran cambios significa-tivos en el espectro de sensibilidad in vitro en relación con publicaciones anteriores en nuestro país. Los cambios en la sensibilidad a los antibióticos deben guiar el diseño de nuevas estrategias terapéuticas más eficaces y rentables.

Antibiotic Sensitivity Patterns in Children with Urinary Tract Infection: Retrospective Study Over 8 Years in a Single Center

Purpose We studied the pathogens and trends in antibiotic sensitivity pattern in children with urinary tract infection (UTI) over 8 years in order to evaluate adequate treatment. Methods We performed a retrospective review of medical records of children with UTI from January 2009 to December 2016 in Daegu Fatima Hospital. Uropathogens and antibiotic sensitivity patterns were selected. Only 1 bacterial species with a colony count of ≥105 CFU/mL was considered a positive result. We compared 2 periods group (A: 2009~2012, B: 2013~2016) to investigate trends of antibiotic sensitivity pattern. Results During the 8 year period, 589 cases are identified (E. coli was cultured in 509 cases, 86.4%). Among all patients, this study investigated the antibiotic sensitivity of E. coli . Antimicrobial susceptibility to ampicillin was steadily low for both periods (A: 32.6%, B: 40.1%, P=0.125), and to amikacin was consistently high for both periods (A: 99.4%, B: 99.3%, P=1.000). Antibiotic sensitivity to third-generation cephalosporin decreased from period A to B (A: 91.7%, B: 75.5%, P=0.000). Antibiotic sensitivity to quinolone significantly decreased from A to B (A: 88.4%, B: 78.2%, P=0.003). The prevalence of extended-spectrum β-lactamase-producing E. coli increased from period A to B (A: 6.1%, B: 17.1%, P=0.000). Conclusion This study showed that conventional antibiotic therapy for the treatment of pediatric UTI needs to be reevaluated. A careful choice of antibiotic is required due to the change in antibiotic sensitivity and the emergence of antibiotic-resistant bacteria. Key words: Urinary tract infection; antibiotic sensitivity; Extended-spectrum β-lactamase

Endogenous rRNA Sequence Variation Can Regulate Stress Response Gene Expression and Phenotype

SUMMARYPrevailing dogma holds that ribosomes are uniform in composition and function. Here, we show that nutrient limitation-induced stress in E. coli changes the relative expression of rDNA operons to alter the rRNA composition within the actively translating ribosome pool. The most upregulated operon encodes the unique 16S rRNA, rrsH, distinguished by conserved sequence variation within the small ribosomal subunit. rrsH-bearing ribosomes affect the expression of functionally coherent gene sets and alter the levels of the RpoS sigma factor, the master regulator of the general stress response. These impacts are associated with phenotypic changes in antibiotic sensitivity, biofilm formation, and cell motility and are regulated by stress response proteins, RelA and RelE, as well as the metabolic enzyme and virulence-associated protein, AdhE. These findings establish that endogenously encoded, naturally occurring rRNA sequence variation can modulate ribosome function, central aspects of gene expression regulation, and cellular physiology.

Ampicillin resistance in Haemophilus influenzae from COPD patients in the UK.

BackgroundHaemophilus influenzae is commonly isolated from the airways of COPD patients. Antibiotic treatment may cause the emergence of resistant H. influenzae strains, particularly ampicillin-resistant strains, including β-lactamase-negative ampicillin resistance (BLNAR) strains. Genetic identification using ftsI sequencing is the optimum method for identifying mutations within BLNAR strains. The prevalence of BLNAR in COPD patients during the stable state has not been reported. We investigated the antibiotic resistance patterns of H. influenzae present in the sputum of stable COPD patients, focusing on ampicillin resistance; the prevalence of enzyme and non-enzyme-mediated ampicillin resistance was determined. A subset of patients was followed up longitudinally to study H. influenzae strain switching and antibiotic sensitivity changes.Patients and methodsSputum sampling was performed in 61 COPD patients, with 42 samples obtained at baseline; H. influenzae was detected by polymerase chain reaction in 28 samples. In all, 45 patients completed the follow-up for 2 years; 24 H. influenzae isolates were obtained.ResultsDisk diffusion showed the highest antibiotic resistance in the penicillin antibiotic group (eg, 67% for ampicillin) and macrolides (eg, 46% for erythromycin), whereas all isolates were susceptible to quinolones. Of the 16 isolates resistant to ampicillin, 9 (56%) were β-lactamase positive. The β-lactamase-negative isolates were further investigated; none of these fulfilled the phenotypic BLNAR classification criteria of ampicillin minimum inhibitory concentration >1 µg/mL, and only one demonstrated an ftsI mutation. Frequent H. influenzae strain switching was confirmed using multilocus sequence typing and was associated with changes in the antibiotic sensitivity pattern.ConclusionWe observed an overidentification of ampicillin resistance by disk diffusion. The majority of ampicillin resistance was due to enzyme production. H. influenzae strain changes during the stable state may be associated with a change in antibiotic sensitivity; this has implications for empirical antibiotic prescribing.

Increased Sensitivity to Chloramphenicol by Inactivation of manB in Streptomyces coelicolor

Phosphomannomutase (ManB) is involved in the biosynthesis of GDP-mannose, which is vital for numerous processes such as synthesis of carbohydrates, production of alginates and ascorbic acid, and post-translational modification of proteins. Here, we discovered that a deletion mutant of manB (BG101) in Streptomyces coelicolor (S. coelicolor) showed higher sensitivity to bacteriostatic chloramphenicol (CM) than the wild-type strain (M145), along with decreased production of CM metabolites. Deletion of manB also decreased the mRNA expression level of drug efflux pumps (i.e., cmlR1 and cmlR2) in S. coelicolor, resulting in increased sensitivity to CM. This is the first report on changes in antibiotic sensitivity to CM by deletion of one glycolysis-related enzyme in S. coelicolor, and the results suggest different approaches for studying the antibiotic-resistant mechanism and its regulation.

Response to Pijl and Crama

Sir, We thank Drs Benjamin Pijl and Niels Crama1 for their instructive comments regarding our article.2 Benjamin Pijl and Niels Crama highlighted the following introductory statement: ‘The information of presenting and final visual acuity (VA) specified to the causative organisms and the choice of the intravitreal antibiotics.' The aim of our paper was to show the spectrum of bacterial isolates that caused endophthalmitis after cataract surgery at our tertiary referral centre in Northern Taiwan, and whether there were differences from findings in other regions. We found that Pseudomonas aeruginosa was the most commonly isolated organism (n=13, 38.2%), and that 12 of 13 patients (92.3%) achieved the final VA worse than 5/200. We agree that details on presenting and final VA of Staphylococcus aureus and other negative bacterial cultures might have provided more information in our study. As we focused our findings on P. aeruginosa and their VA outcome, we provided the data concisely. Using ceftazidime instead of amikacin led to a higher rate of antibiotic susceptibility in our study. Thus, concerns have emerged that ceftazidime may positively influence future treatment outcome in acute postoperative bacterial endophthalmitis after cataract surgery among the population in Northern Taiwan. We treated our patients with a regimen of intravitreal vancomycin and amikacin rather than vancomycin and ceftazidime. We thus concluded that the use of regimen (vancomycin and amikacin) still provides good coverage in our region. On the basis of the results of antibiotic susceptibility in our study, one might argue that ceftazidime is better than amikacin in Northern Taiwan. A change in antibiotic sensitivity has been reported over the past two decades.3 It definitely needed to be periodically surveyed. However, there was in fact not enough clinical evidence in our study for the claim by Drs Benjamin Pijl and Niels Crama. Obviously, further investigation should continue to provide information about post-cataract endophthalmitis. We appreciate Drs Benjamin Pijl and Niels Crama's interest and thank them for giving us an opportunity to consider an important point that we had not fully expressed.

Vicissitude of antibiotic sensitivity of Gram negative bacilli in patients with infection in emergency departments in Beijing during 2005 to 2007

To investigate changes in antibiotic sensitivity of Gram negative bacilli infections among emergency patients in large hospitals in Beijing during 2005 to 2007. Retrospective analysis of all the identified strains of Gram negative bacilli, and their sensitivity to antibiotic obtained in the emergency departments of 5 top first-class hospitals in Beijing for recent 3 years. Two thousand two hundred and eighty-five strains of Gram negative bacilli had taken 64.62% of all, the priority 5 of which were Pseudomonas aeruginosa (23.89%), Escherichia coli (19.91%), Acinetobacter baumanii (17.59%), Klebsiella pneumoniae (8.05%) and Staphylococcus maltophilia (3.94%). The sensitivity of commonly used antibiotics plummeted greatly in recent 3 years, especially carbapenems, cephalosporins and quinolones. The resistance of imipenem-resistant Pseudomonas aeruginosa was 17.30%, 22.53%, 31.92% respectively. The resistance of imipenem-resistant Acinetobacter baumanii was 13.87%, 12.09%, 23.56% respectively. Infectious bacteria in emergency departments in Beijing top first-class hospitals tend to show the characteristics of hospital infection. In recent years, the sensitivity of bacilli to antibiotic has dropped greatly. The situation of antibiotics resistance might be depressed.

Prevention of Group B Streptococcus early-onset disease: a toolkit by the California Perinatal Quality Care Collaborative

The California Perinatal Quality Care Collaborative (CPQCC) was organized in 1996 in an effort to improve perinatal outcomes in California. CPQCC has a robust infrastructure of quality improvement resources and expertise and uses a database of demographic and outcome data from neonatal intensive care units in California. In 2004, CPQCC developed a toolkit to provide an evidence-based framework and supporting documents for hospitals to use in systematically addressing persistent early-onset disease (EOD) because of Group B Streptococcus (GBS) in their centers. The CPQCC toolkit was based on the 2002 Centers for Disease Control guideline, 'Prevention of Perinatal Group B Streptococcal Disease.' This article presents an updated version of the CPQCC toolkit reflecting several population studies published since the 2002 guideline. Current epidemiological trends in incidence of EOD with GBS, changes in antibiotic sensitivity and the potential value of newer strategies are discussed.

Prevention of nosocomial lower respiratory tract infections in patients after intracranial artery aneurysm surgery with a short course of antimicrobials

Nosocomial infections at a department of neurosurgery were followed prospectively. In 1999, a high incidence of nosocomial lower respiratory tract infections (NLRTI) was observed in patients after intracranial artery aneurysm surgery (ICAAS). From February to December 2000, a short course of ciprofloxacin and co-trimoxazole was given prophylactically to all patients with ICAAS. The incidence of nosocomial infections in patients after ICAAS fell from 78.4 to 30.9% ( P<0.0001). The incidence of NLRTI fell from 43.3 to 13.6% ( P<0.0001) and the incidence of urinary tract infections from 12.4 to 2.5% ( P=0.015). No significant change in antibiotic sensitivity at the department was observed. Antibiotic use decreased from 100.4 defined daily doses (DDD) to 85.4 DDD per 100 bed-days.

Reviews and Original Articles

The recommendations provided in this document represent a distillation of various experiences, as well as data obtained from published studies in the setting of substantial changes in antibiotic sensitivity. It is hoped that this revised compilation will provide a basis upon which future developments and advances can be made in the therapeutic approach to infectious complications of peritoneal dialysis.