Empirical Treatment Of Infections Research Articles

Identification of pathogenic bacteria isolated from wound infections, and effect of some antibiotics

In clinical practice, where empiric treatment of infections is common, wound infections are still a problem. Purpose: In this study, it was aimed to identification of pathogenic bacteria isolated from wound infections, and Effect of some antibiotics at Wasit, Iraq. Methods: Records of 102 patients' wound swabs taken with a suspicion of wound infections. Swabs from the wounds were used to inoculate and culture smears. Gram-stained bacterial colonies were studied under a microscope. To determine the types of pathogens, biochemical tests were conducted. For evaluating antibiotics, the Kirby-Bauer disk diffusion method was employed. Results: Infections in wounds were prevalent 81.4% (CI: 60.869).83 infected wounds yielded a total of 10 distinct species. Staphylococcus aureus (26.5%)was the most prevalent bacterial species found, followed by Pseudomonas aeruginosa(14.4%), Proteus mirabilis (12%), Escherichia coli (10.8%), and Enterobacter cloacae (8.4%). Two species made up the majority of the 25 (30.1%) polymicrobial infections that were discovered in the samples. The P. aeruginosa and P. mirabilis relationship was the most frequent. The studied antibiotic resistance levels among the bacterial isolates varied (8.3% to 100%) resistance. Amoxicillin-clavulanate resistance was present in all isolates.Age and sex had no bearing on the prevalence, type of agent, and pattern of antimicrobial resistance.

Epidemiology and Traits of Mobile Colistin Resistance (mcr) Gene-Bearing Organisms from Horses.

Mobile colistin resistance (mcr) genes (mcr-1 to mcr-10) threaten the efficacy of colistin (COL), a polymyxin antibiotic that is used as a last-line agent for the treatment of deadly infections caused by multidrug-resistant and extensively drug-resistant bacteria in humans and animals. COL has been used for more than 60 years for the prophylactic control and treatment of infections in livestock husbandry but not in horses. Polymyxin B is used for the prophylactic control and empirical treatment of infections in horses without conducting sensitivity tests. The lack of sensitivity testing exerts selection pressure for the acquisition of the mcr gene. By horizontal transfer, mcr-1, mcr-5, and mcr-9 have disseminated among horse populations globally and are harbored by Escherichia coli, Klebsiella, Enterobacter, Citrobacter, and Salmonella species. Conjugative plasmids, insertion sequences, and transposons are the backbone of mcr genes in the isolates, which co-express genes conferring multi- to extensive-drug resistance, including genes encoding extended-spectrum β-lactamase, ampicillinase C, fosfomycin, and fluoroquinolone resistance, and virulence genes. The transmission of mcr genes to/among bacterial strains of equine origin is non-clonal. Contact with horses, horse manure, feed/drinking water, farmers, farmers’ clothing/farm equipment, the consumption of contaminated horse meat and its associated products, and the trading of horses, horse meat, and their associated products are routes for the transmission of mcr-gene-bearing bacteria in, to, and from the equine industry.

700 Use of Antibiograms and Changes in Bacterial Resistance Patterns

IntroductionInfection is a leading cause of death in burn patients. With an increase in resistance patterns, management of these infections has become progressively difficult. Antibiograms, a summary of susceptibilities to bacteria in a given institution or area, are often used to guide empiric treatment of infections. However, inappropriate prescribing and use of empiric antimicrobials may greatly impact the incidence of resistance. Currently, we do not know the patterns of antibiotic use since the introduction of institutional antibiograms or associated changes in antibiotic resistance. The objective of this study is to describe trends in antibiotic susceptibilities in burn patients in Canada pre- (PrA) and post-introduction (PoA) of antibiograms.MethodsWe performed a retrospective review of patients admitted to an ABA-verified Burn Centre 2 years pre- (2013-2014) and post-introduction (2016-2017) of institutional antibiograms and started on broad-spectrum antibiotics (meropenem, piperacillin-tazobactam, and/or vancomycin).ResultsA total of 864 patients were admitted during the study period (n=420 PrA and n=444 PoA). Average age, % total body surface area (%TBSA), and length of stay were similar between cohorts. Administration of empiric meropenem increased (43.2% vs. 56.8%) and piperacillin-tazobactam decreased (60.6% vs. 39.4%), which was significant (p=0.002). The use of vancomycin was unchanged. There was a significant decrease in the overall use of empiric antibiotics (p=0.002) since the inception of antibiograms, with a significant improvement in culture and sensitivity (C&S) testing within 5 days of starting empiric antibiotics (p=0.002). There was no significant difference in use of targeted antibiotics pre- or post-antibiogram introduction.ConclusionsOur study demonstrates that since the inception of antibiograms, there has been a significant decrease in overall use of empiric antibiotics and improvement in acquiring C&S within 5 days. However, these antibiotics were not always targeted to the appropriate organism and therefore may contribute to multi-drug resistant organisms in a burn population.

The Path of More Resistance: a Comparison of National Healthcare Safety Network and Clinical Laboratory Standards Institute Criteria in Developing Cumulative Antimicrobial Susceptibility Test Reports and Institutional Antibiograms.

In the absence of antimicrobial susceptibility data, the institutional antibiogram is a valuable tool to guide clinicians in the empirical treatment of infections. However, there is a misunderstanding about how best to prepare cumulative antimicrobial susceptibility testing reports (CASTRs) to guide empirical therapy (e.g., routine antibiogram) versus monitoring antimicrobial resistance, with the former following guidance from the Clinical and Laboratory Standards Institute (CLSI) and the latter from the Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN). These criteria vary markedly in their exclusion or inclusion of isolates cultured repeatedly from the same patient. We compared rates of nonsusceptibility (NS) using annual data from a large teaching health care system subset to isolates eligible by either NHSN criteria or CLSI criteria. For a panel of the three most prevalent Gram-negative pathogens in combination with clinically relevant antimicrobial agents (or priority pathogen-agent combinations [PPACs]), we found that the inclusion of duplicate isolates by NHSN criteria yielded higher NS rates than when CLSI criteria (for which duplicate isolates are not included) were applied. Patients with duplicate isolates may not be representative of antimicrobial resistance within a population. For this reason, users of CASTR data should carefully consider that the criteria used to generate these reports can impact resulting NS rates and, therefore, maintain the distinction between CASTRs created for different purposes.

Проблеми лікування та профілактики пневмококової інфекції в дітей

Актуальність. Streptococcus pneumoniae — одна з головних причин інвазивних та неінвазивних захворювань різної локалізації у всіх вікових групах по всьому світі. Пневмокок — вбивця № 1 для дітей до 5 років: 40 % в структурі смертності, 500 000 життів на рік. Глобальне зростання стійкості до антибіотиків створює проблеми емпіричного лікування інфекції. Вакцинація проти пневмокока — найбільш дієвий засіб контролю над інфекцією. Вибір вакцини «повинен ґрунтуватись на наявній місцевій чи регіональній оцінці розподілу серотипів пневмокока в різних вікових групах» (ВООЗ). Мета: визначити у дітей серотиповий склад пневмококів при носійстві та при гнійному менінгіті, їх відповідність до вакцинальних штамів і чутливість до антибіотиків. Матеріали та методи. Було взято під спостереження 900 здорових дітей віком від 6 місяців до 5 років. Для дослідження бралися назофарингеальні мазки спеціально навченими медичними сестрами. Ідентифікація пневмококів проводилась класичним культуральним методом та ПЛР у реальному часі. Визначення чутливості до 13 антибіотиків виконувалося диско-дифузійним методом та методом серійних розведень. Серотипування пневмококів проводили з використанням мультиплексної ПЛР. Перевіряли носійство 15 серотипів пневмокока, 13 з яких входять до складу ПКВ 13. Результати. При використанні культурального методу було виділено пневмококи з носоглотки у 21,3 % дітей перших 5 років життя. При використанні ПЛР — у 53,8 % дітей. Бар’єр резистентності до 25 % пневмококів, при якому вже недоцільно застосовувати препарат, переступили такі антибіотики, як котримоксазол, еритроміцин та азитроміцин. До амоксициліну/клавуланату, який поки що є антибіотиком першої лінії для лікування позалікарняної пневмонії, 28,3 % пневмококів, що визначалися при назофарингеальному носійстві у дітей до 5 років, виробили часткову резистентність. Від здорових носіїв не було виділено жодного ізоляту пневмокока з високою резистентністю до цефалоспоринів ІІІ покоління. Мультирезистентні пневмококи із серотипами 14, 6А/В, 19F та НТ-штами разом становлять 52,2 % при носійстві у дітей та 69,1 % при менінгіті. Серотипи, що входять до складу ПКВ 13, збігаються в 65,53 % із серотипами, що виділялися при назофарингеальному носійстві, та в 87,5 % при гнійному менінгіті в дітей. Висновки. Основним джерелом пневмококів є фарингеальне носійство, яке зустрічається у здорових дітей перших п’яти років життя. Збудником пневмококових менінгітів є ті ж серотипи пневмококів, які колонізують носоглотку дітей. Селекція резистентних штамів пневмокока відбувається переважно в дітей при назофарингеальному носійстві. Результати визначення збігу вакцинальних серотипів ПКВ та серотипів пневмококів при носійстві та гнійному менінгіті дозволяють прогнозувати, що введення універсальної вакцинації проти пневмококової інфекції буде зменшувати носійство пневмококів майже на 66 % та захистить від пнемококових менінгітів більше ніж 87 % дітей.

1162. Engraftment fever (EF) in Pediatric stem cell transplantation (SCT): Risk Factors, Etiology and Outcomes

BackgroundEngraftment fever (EF) during stem cell transplantation (SCT) is likely due to non infectious causes like immune reconstitution syndrome (IRS) or engraftment syndrome (ES). Few studies have looked at the rate of infection causing fever during engraftment. There is no good evidence to guide the approach to evaluation and empiric treatment of infections during EF.MethodsRetrospective record review of pediatric SCT (autologous and allogenic) patients with a diagnosis of febrile neutropenia (FN) during engraftment period (days +7 to +30 post transplant). FN episodes classified as either EF or non-engraftment fever (NEF). EF = new onset fever in temporal relationship to neutrophil recovery (4 days before through 1 day after neutrophil engraftment (ANC >500/mm3). NEF = fever without signs of neutrophil recovery (ANC < 100/mm3 without significant rise ±4 days of fever onset). Only first FN during engraftment was included. Episodes meeting neither criteria were excluded.Results112 patients had 115 FN episodes (FNEs) identified: NEF 81 (71.5%); EF 34 (29.5%). In multivariable analysis: Neuroblastoma as underlying diagnosis (odds ratio [OR]=3.2, 95% CI 2.31-6.54, P< 0.01), G-CSF administration before day +7 (OR=2.8, 95% CI 1.92-4.65, P=0.03), absolute monocyte count (AMC) >100/mm3 at FN presentation (OR=2.9, 95% CI, 1.11 to 7.55, P=0.02), were associated with an increased risk of EF compared with NEF. Most EF episodes (26/34, 76%) had no specific infectious etiology identified; 8 had IFIs (24%) [3 proven, 2 probable, 3 possible). IFI rate was higher in EF than NEF group (24% vs 5%) (OR=4.5, 95% CI, 2.11 to 9.55, P< 0.01. EF episodes were more likely to be admitted to the intensive care unit (OR=2.3, 95% CI, 1.88 to 6.35) and had higher 30-day mortality (OR =4.52, 95% CI, 0.37 to 6.55) than NEF.Table 3 table 2 ConclusionEngraftment fever may have an infectious component. Work-up to exclude IFI and empirical antifungal therapy should be considered especially with prolonged fever and supportive clinical or radiological data. Large multi-center prospective studies are needed to further define infectious complications and determine the approach to engraftment fever. Early detection of IFI in this high-risk group may lead to improved morbidity and mortality.Disclosures All Authors: No reported disclosures

INFECTIOUS COMPLICATIONS CAUSED BY NON-SPOREFORMING ANAEROBIC BACTERIA IN CANCER PATIENTS. RELEVANCE OF THE PROBLEM

The purpose of the study : to identify the significance of anaerobic bacteria and analyze their role in the development of infectious complications in cancer patients. Material and Methods . The review includes data from clinical and in vitro studies published in Russian and international press for the period from 1989 to 2018. Results . Data analysis has shown that many aspects related to anaerobic non-sporeforming bacteria are insufficiently studied, although they can cause severe hospital infections. This is especially true for patients with immune system defects, including cancer patients. In this category of patients, anaerobic bacteria can cause infections of the maxillofacial region, intra-abdominal infections, lower respiratory tract infections, urinary infections, and blood flow infections. In cancer patients, infectious complications are more severe, and may adversely affect treatment outcomes. A long process of anaerobic cultivation dictates the need for empirical treatment of infection for an average of 6 to 7 days. Since the middle of the last century, metronidazole was the «gold standard» of therapy. However, today the situation has changed dramatically. More than 80 % of anaerobic strains are resistant to metronidazole. The problem of resistance of anaerobic bacteria to other antibacterial drugs has not been sufficiently studied. Conclusion . It is necessary to develop therapeutic approaches based on current data on the resistance mechanisms of non-sporeforming anaerobic bacteria.

АНТИБІОТИКИ В СТОМАТОЛОГІЇ

Стаття узагальнює аргументи та контраргументи в межах наукової дискусії з питання щодо використання антибіотиків в стоматології. Основною метою проведеного дослідження є аналіз різних клінічних ситуацій, які потребують застосування протимікробних препаратів. Метод дослідження ґрунтувався на вивченні наукових статей, опублікованих в період з 2005 по 2019 рр. індексованих в Україні та міжнародних базах даних, а також на порівнянні різних рекомендацій з призначення антибіотиків в стоматології, опублікованих у розвинених країнах світу. Систематизація літературних джерел та підходів до вирішення проблеми профілактики та лікування гнійно-запальних інфекцій у стоматології засвідчила, що антибіотики, які застосовуються в різних країнах світу, сходяться на раціональному і обґрунтованому застосуванні протимікробних препаратів. Переважна більшість дослідників вважають, що антибіотики слід використовувати тільки в рекомендованих ситуаціях для пацієнтів з ризиком розвитку гнійно-запальних інфекцій після стоматологічних процедур. Однак, питання щодо раціонального використання як для профілактики, так і для емпіричного лікування інфекцій за допомогою антибіотиків в стоматології, залишається невирішеними. Насамперед, це пов’язано з постійною зміною біологічних властивостей, зокрема стійкості до антибіотиків збудників гнійно-запальних інфекцій ротової порожнини. Цій темі присвячені лише поодинокі дослідження, а сучасних даних у доступній літературі немає. В Україні офіційно затверджених рекомендацій щодо використання антибіотиків в стоматології немає. Відсутній також на державному рівні епідеміологічний нагляд за резистентністю збудників інфекцій, зокрема ротової порожнини. Крім того, не вивчено питання щодо ефективності використання антибіотиків в стоматології. Необхідне проведення додаткових досліджень з вивчення появи та поширення мікроорганізмів, резистентних до дії протимікробних препаратів в закладах охорони здоров’я, зокрема в амбулаторних умовах застосування лікарями-стоматологами антибіотиків, які, згідно з деякими міжнародними рекомендаціями, здаються широко поширеними і не обмежуються ситуаціями, описаними в керівних принципах асоціацій стоматологів розвинених країн світу. Таким чином, лікарі-стоматологи повинні бути обережними у застосуванні антибіотиків, як для лікування, так і профілактики інфекцій, і призначати антибіотики тільки в тому випадку, якщо це рекомендовано керівними принципами, заснова-ними на результатах доказової медицини, а також ефективно і безпечно.

Spectrum of Aerobic Bacterial Pathogen isolated from Pus samples and their Antibiotic Sensitivity Pattern in a Tertiary Care Hospital

Background:Wound infection continues to be a significant problem in clinical practice where empirical treatment of infection is required while waiting for culture report to prevent emergence of resistance. Objectives:To study the spectrum of aerobic bacterial pathogen isolated from pus samples and to determine the antimicrobial sensitivity pattern of the bacteria isolated. Method: The samples of pusreceived in Clinical Microbiology Laboratory were processed during the study period to isolate and identify bacterial pathogens as per standard bacteriologicaltechniques. Antibiotic susceptibility testing was done by Kirby Bauer disc diffusion method as per CLSI guidelines 2017. Result:Out of the total of 1474pus samples processed, 21.98% samples were culture positive. Majority of culture positive samples were from IPD patients.Predominance of gram negative bacteria (77.4%) was seen as compared to gram positive bacteria (22.60%) both in IPD and OPD samples. High level of resistance to various antimicrobials was seen among the clinical isolates. Conclusion: Emergence of antibiotic resistant strains in pus sample is a matter of concern. Therefore, knowledge of the spectrum of microorganisms causing pus discharge and its susceptibility pattern is required and this data may contribute to an effective management of cases of wound infection

PREVALENCE OF BACTERIAL RESISTANCE IN HOSPITALIZED CIRRHOTIC PATIENTS IN SOUTHERN BRAZIL: A NEW CHALLENGE.

Background & Aims:An increased frequency of infections by multiresistant bacteria has been described in hospitalized patients. The aim of this study was to evaluate the bacterial resistance profile in cirrhotic patients. Methods:This is a retrospective observational study. We assessed the antimicrobial susceptibility of 5,839 bacterial isolates from patients with and without cirrhosis. Regarding the multidrug resistance, we evaluated 4,505 bacterial isolates from 2,180 patients. Results:Two hundred and fifty-one patients had cirrhosis (mean age 57.6 ± 11 years; 61.8% were male, 47.8% of cases associated with hepatitis C virus). Of the isolates of patients with and without cirrhosis, 174/464 (37.5%) and 1,783/4,041 (44.1%) were multiresistant, respectively (p = 0.007). E. coli was the most common multiresistant bacteria in both groups. Approximately 20% of E. coli and Klebsiella sp. isolates were ESBL-producers and 44% of S. aureus isolates were methicillin-resistant in cirrhotic patients. In cirrhotic patients admitted to the emergency department, hospital ward, and intensive care unit, 28.3%, 50% and 40% had multiresistant isolates, respectively. In patients with and without cirrhosis, 36.2% and 33.5% of isolates were resistant to third-generation cephalosporins, respectively. Conclusions: The empirical treatment of infections in hospitalized patients using broad-spectrum antibiotics should consider the observed pattern of bacterial resistance.

Making Antibiotic Choices: Formula Derivation and Usage in the Rational Selection of Antibiotics in the Empirical Treatment of Infections

Purpose: To develop mathematical formulae to aid the selection of antibiotics most appropriate in the empirical treatment of infections.Methods: Formulae quantifying the characteristics of antibiotics with regard to their cost and activity against associated bacterial isolates of given infections were derived from probability laws. Data from records of culture sensitivity test results were compiled and analysed to ascertain bacterial pathogen associations with infections and their sensitivities to prescribed antibiotics. Applicability of derived formulae was demonstrated in the rational selection of antibiotics most appropriate in the empirical treatment of urinary tract infections (UTIs) in selected hospitals in Lesotho.Results: Escherichia. coli, followed by Klebsiella spp, Proteus spp, non-haemolytic Streptococci, Streptococcus pyogenes and then, Pseudomonas spp were identified as the most common uropathogens at the hospitals studied. Two mathematical formulae were derived and used in quantifying activity and cost characteristics of prescribed antibiotics. Cefotaxime, followed by ciprofloxacin - were considered most appropriate for use in treating UTIs empirically among inpatients of the hospitals.Conclusion: Quantifying and using procedurally antibacterial activities and cost characteristics of antibiotics provides a suitable means of making antibiotic choices in the empirical treatment of infections.Keywords: Antibiotics, Derived formulae, Rational selection, Empiric treatment, Urinary tract infection, Lesotho.

A study of utilization pattern, efficacy and safety of drugs prescribed for opportunistic infections in Human Immunodeficiency Virus infected patients

Objectives: The aim was to evaluate the utilization pattern, efficacy and safety of drugs prescribed for opportunistic infections (OIs) in human immunodeficiency virus (HIV) positive patients. Materials and Methods: In this observational, prospective, single center study, HIV positive patients were followed-up for a period of 1 year to record the OIs; their clinical course and outcome. Utilization pattern, efficacy and safety of the drugs used were evaluated. Rationality of treatment was assessed using National AIDS Control Organization and Standard Treatment Guidelines. Results: A total of 222 OIs were detected in 134 patients. Majority of patients (90.2%) were adults. The commonest OIs included tuberculosis (TB) (89), oropharyngeal candidiasis (OPC) (37), bacterial infections (30) and chronic diarrhea (22). Use of supportive drugs and empirical treatment of certain OIs contributed to a higher number of drugs (average of 3.5 drugs) per prescription. Drugs, prescribed in accordance with the above mentioned guidelines, were effective in most cases. Drugs were well-tolerated with only two serious adverse drug reactions (ADRs) reported. Majority of ADRs were associated with anti TB drugs. Conclusion: Tuberculosis, oropharyngeal candidiasis, bacterial infections and chronic diarrhea are the commonest OIs. Overall, a rational approach to therapy and good tolerability and efficacy of drugs was observed. Empirical treatment of infections should be minimized.

Pharmacoeconomic evaluation of voriconazole vs. liposomal amphotericin B in empiric treatment of invasive fungal infections in Turkey

BackgroundInvasive fungal infections (IFI) are associated with considerable expense and mortality on healthcare systems. There is a need to provide evidence of both clinical efficacy and value for money with any health technology. The current pharmacoeconomic evaluation investigated the use of liposomal amphotericin B (LAmB) and voriconazole for the empiric treatment of IFI in the Turkish setting.MethodsDecision analytic modelling was used to create a pathway for patient treatment with a 5-point composite outcome measure. The data was obtained from a major non-inferiority multicentre randomised controlled study, with an expert panel of clinicians in Turkey providing transition probabilities and cost not available in the literature. Sensitivity analyses were performed on the inputs from the clinical trial and the expert panel.ResultsAs per the base case analysis, voriconazole was preferred by Turkish Lira (TL) 2,523 per patient treated and TL2,520 per surviving patient. LAmB was the preferred alternative by TL5,362 per successfully treated patient. Removing fever resolution as part of the composite outcome measure resulted in voriconazole being the preferred alternative per successfully treated patient. Univariate sensitivity analysis highlighted that increasing the duration of voriconazole by >1.2 days or decreasing LAmB by >1.0 days changes the result. Monte Carlo Simulation resulted in 69.4% of simulations favouring voriconazole per patient treated.ConclusionThere is a strong likelihood that voriconazole is economically more favourable than LAmB in the empiric treatment of IFI in Turkey.

Current Microbial Isolates from Wound Swabs, Their Culture and Sensitivity Pattern at the Niger Delta University Teaching Hospital, Okolobiri, Nigeria

Background: Wound infections continue to be problematic in clinical practice where empiric treatment of infections is routine. Objectives: A retrospective cross-sectional study to determine the current causative organisms of wound infections and their antibiotic susceptibility patterns in the Niger Delta University Teaching Hospital (NDUTH), Okolobiri, Bayelsa State of Nigeria. Methods: Records of wound swabs collected from 101 patients with high suspicion of wound infection were analysed. Smears from the wound swabs were inoculated on appropriate media and cultured. Bacterial colonies were Gram stained and microscopically examined. Biochemical tests were done to identify pathogen species. The Kirby-Bauer disk diffusion method was used for antibiotic testing. Results: Prevalence of wound infection was 86.13% (CI: 79.41–92.85). Most bacteria were Gram negative bacilli with Pseudomonas aeruginosa being the most prevalent pathogen isolated. The bacterial isolates exhibited a high degree of resistance to the antibiotics tested (42.8% to 100% resistance). All isolates were resistant to cloxacillin. Age group and sex did not exert any effect on prevalence, aetiological agent or antimicrobial resistance pattern. Conclusion: We suggest a multidisciplinary approach to wound management, routine microbiological surveillance of wounds, rational drug use and the institution of strong infection control policies.

Characterization of Neisseria meningitidis isolates from Egypt using multilocus sequence typing

To characterize Neisseria meningitidis isolates collected from cerebrospinal fluid of meningitis cases in Egypt (1998-2003) as part of surveillance studies, 67 isolates were serogrouped, tested for antibiotic sensitivity and analyzed using multilocus sequence typing (MLST). Results show that isolates expressing serogroup B (50.7%) and serogroup A (34.3%) antigens were predominant in Egypt during the surveillance period, possibly due to suppression of other serogroups by meningococcal vaccines in current use. Intermediate resistance to penicillin was observed in 71% of the isolates, suggesting a need for physicians to shift to third-generation cephalosporins during the empirical treatment of infection. Recurrent lineages of N. meningitidis in Egypt appear to originate from Europe and other Middle Eastern countries. Of 19 sequence types detected, five were unique to Africa and 10 were not observed previously in the MLST database. The information obtained illustrates the changing dynamics of meningitis after vaccine introduction in Egypt.

Prophylaxis and treatment of infections associated with penetrating traumatic injury

Accidents or violence can result in penetrating trauma in the adult population. Contaminated penetrating foreign bodies introduced at the time of wounding cause infection, especially high velocity projectiles, which result in cavitation. Surgical debridement reduces potential infection; however, perioperative antibiotics are usually indicated owing to studies demonstrating high rates of sepsis in the pre-antibiotic era. Trauma-associated pathogens include Gram-positive, Gram-negative and anaerobic pathogens. Antibiotic resistance is increasing, and several recent panels have sought to develop guidelines for perioperative prevention and empiric treatment of infection to limit usage and reduce selective pressure for resistance. We review infections of the CNS, thorax, abdomen and extremities following penetrating trauma injury, as well as the data supporting a reasonable antimicrobial approach.

Antimicrobial susceptibilty of potentially pathogenic halophilic Vibrio species isolated from seafoods in Lagos, Nigeria

Surveillance of antimicrobial resistance is indispensable for empirical treatment of infections and in preventing the spread of antimicrobial resistant microorganisms. This study is aimed at determining the antibiotic susceptibility of potentially pathogenic halophylic Vibrio species isolated in Lagos, Nigeria. Susceptibility patterns to ten (10) antibiotics were investigated in 44 potentially pathogenic halophilic Vibrio species isolated from sea foods in Lagos. Antimicrobial susceptibility tests showed that all the isolates (100%) were resistant to amoxicillin, augmentin, chloramphenicol and nitroforantoin. They also showed multiple resistance patterns to Gentamycin, Nitrofurantoin, Tetracycline, Augmentin, Chloramphenicol, Amoxycilin, Ofloxacin, Cotrimozazole, Ceftriazone, and Ciprofloxacin. Resistance to all ten antibiotics occurs in 8 (18%) of the isolates. Among individual sp., Vibrio harveyi was found to be most resistant to the antibiotics screened. Infection caused by Vibrio contaminating sea foods in this envinronment will be difficult to treat because of their high antibiotic resistant nature. Key words: Vibrio species, antibiotic resistance, Lagos.

In vitro evaluation of antibiotics' combinations for empirical therapy of suspected methicillin resistant Staphylococcus aureussevere respiratory infections

BackgroundMethicillin resistant Staphylococcus aureus (MRSA) is an increasingly common cause of nosocomial infections, causing severe morbidity and mortality worldwide, and accounting in some hospitals for more than 50% of all S. aureus diseases. Treatment of infections caused by resistant bacterial pathogens mainly relies on two therapeutic modalities: development of new antimicrobials and use of combinations of available antibiotics.Combinations of antibiotics used in the empiric treatment of infections with suspected methicillin resistant Staphylococcus aureus etiology were investigated.MethodsDouble (vancomycin or teicoplanin with either levofloxacin or cefotaxime) and triple (vancomycin or teicoplanin + levofloxacin + one among amikacin, ceftazidime, cefepime, imipenem, piperacillin/tazobactam) combinations were evaluated by means of checkerboard assay and time kill curves. Mutational rates of single and combined drugs at antimicrobial concentrations equal to the resistance breakpoints were also calculated.ResultsVancomycin or teicoplanin + levofloxacin showed synergy in 16/50 and in 9/50 strains respectively, while vancomycin or teicoplanin + cefotaxime resulted synergic for 43/50 and 23/50 strains, respectively. Triple combinations, involving teicoplanin, levofloxacin and ceftazidime or piperacillin/tazobactam gave synergy in 20/25 strains. Teicoplanin + levofloxacin gave synergy in triple combinations more frequently than vancomycin + levofloxacin.For single antibiotics, mutational frequencies ranged between 10-5 and <10-9 for levofloxacin, cefotaxime, amikacin and imipenem, and <10-9 for vancomycin and teicoplanin. When tested in combinations, mutational frequencies fell below 10-9 for all the combinations.ConclusionIn vitro evidence of synergy between glycopeptides, fluoroquinolones (levofloxacin) and β-lactams and of reduction of mutational frequencies by combinations are suggestive for a potential role in empirical therapy of severe pneumonia with suspected MRSA etiology.

Control of multi-resistant bacteria and ventilator-associated pneumonia: is it possible with changes in antibiotics?

Potent antimicrobial agents have been developed as a response to the development of antibiotic-resistant bacteria, which especially affect patients with prolonged hospitalization in Intensive Care Units (ICU) and who had been previously treated with antimicrobials, especially third-generation cephalosporins. This study was to determine how changes in the empirical treatment of infections in ICU patients affect the incidence of Gram-negative bacteria species and their susceptibility to antimicrobials, and examine the impact of these changes on nosocomial infections. A prospective interventional study was performed in a university hospital during two periods: 1) First period (September 1999 to February 2000); and 2) Second period (August 2000 to December 2000); empirical treatment was changed from ceftriaxone and/or ceftazidime in the first period to piperacillin/tazobactam in the second. ICU epidemiological and infection control rates, as well as bacterial isolates from upper airways were analyzed. Ceftazidime consumption dropped from 34.83 to 0.85 DDD/1000 patients per day (p=0.004). Piperacillin/tazobactam was originally not available; its consumption reached 157.07 DDD/1000 patients per day in the second period (p=0.0002). Eighty-seven patients and 66 patients were evaluated for upper airway colonization in the first and second periods, respectively. There was a significant decrease in the incidence of K. pneumoniae (p=0.004) and P. mirabilis (p=0.036), restoration of K. pneumoniae susceptibility to cephalosporins (p<0.0001) and reduction of ventilator-associated pneumonia rates (p<0.0001). However, there was an increase in P. aeruginosa incidence (p=0.005) and increases in ceftazidime (p=0.003) and meropenem (p<0.0001) susceptibilities. Changing antimicrobial selective pressure on multi-resistant Gram-negative bacteria helps control ventilator-associated pneumonia and decreases antimicrobial resistance.

Molecular Characterization of Increasing Fluoroquinolone Resistance in Streptococcus pneumoniae Isolates in Canada, 1997 to 2005

Molecular characterization of fluoroquinolone-resistant Streptococcus pneumoniae in Canada was conducted from 1997 to 2005. Over the course of the study, 205 ciprofloxacin-resistant isolates were evaluated for ParC and GyrA quinolone resistance-determining region (QRDR) substitutions, substitutions in the full genes of ParC, ParE, and GyrA, reserpine sensitivity, and serotype and by pulsed-field gel electrophoresis. Rates of ciprofloxacin resistance of S. pneumoniae increased significantly, from less than 1% in 1997 to 4.2% in 2005. Ciprofloxacin resistance was greatest in people >64 years of age and least in those <16 years of age. Significant increases were also noted in rates of resistance to gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin, to the current rates of 1.6%, 1.0%, 1.1%, and 1.0%, respectively. The most common genotype observed consisted of QRDR substitutions in GyrA (Ser81Phe) and ParC (Ser79Phe). Substitutions outside the QRDR of GyrA, ParC, and ParE were not associated with fluoroquinolone resistance in this study. Overall, 21% of isolates were reserpine-sensitive and were thus assumed to be efflux positive. The ciprofloxacin-resistant isolates belonged to 35 different serotypes, but 10 (19F, 11A, 23F, 6B, 22F, 12F, 6A, 14, 9V, and 19A) accounted for 72% of all isolates. The majority of the isolates were found to be genetically unrelated by pulsed-field gel electrophoresis. Within the observed clusters, there was considerable genetic heterogeneity with regard to fluoroquinolone resistance mechanisms and serotypes. Continued surveillance and molecular analysis of fluoroquinolone-resistant S. pneumoniae in Canada are essential for appropriate empirical treatment of infections and early detection of novel resistance mechanisms.