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PubMed2004

Optimal use of antibiotic resistance surveillance systems.

Increasing concern about the emergence of resistance in clinically important pathogens has led to the establishment of a number of surveillance programmes to monitor the true extent of resistance at the local, regional and national levels. Although some programmes have been operating for several years, their true usefulness is only now being realised. This review describes some of the major surveillance initiatives and the way in which the data have been used in a number of different settings. In the hospital, surveillance data have been used to monitor local antibiograms and determine infection control strategies and antibiotic usage policies. In the community, surveillance data have been used to monitor public health threats, such as infectious disease outbreaks involving resistant pathogens and the effects of bioterrorism countermeasures, by following the effects of prophylactic use of different antibiotics on resistance. Initially, the pharmaceutical industry sponsored surveillance programmes to monitor the susceptibility of clinical isolates to marketed products. However, in the era of burgeoning resistance, many developers of antimicrobial agents find surveillance data useful for defining new drug discovery and development strategies, in that they assist with the identification of new medical needs, allow modelling of future resistance trends, and identify high-profile isolates for screening the activity of new agents. Many companies now conduct pre-launch surveillance of new products to benchmark activity so that changes in resistance can be monitored following clinical use. Surveillance data also represent an integral component of regulatory submissions for new agents and, together with clinical trial data, are used to determine breakpoints. It is clear that antibiotic resistance surveillance systems will continue to provide valuable data to health care providers, university researchers, pharmaceutical companies, and government and regulatory agencies.

Anti-Bacterial Agents↗
PubMed2001

Epidemiology and frequency of resistance among pathogens causing urinary tract infections in 1,510 hospitalized patients: a report from the SENTRY Antimicrobial Surveillance Program (North America).

Bacterial urinary tract infections (UTIs) are an important cause of septicemia resulting in high mortality rates, prolonged hospital stays and increased healthcare costs. Periodic reviews of pathogen frequency and susceptibility patterns impact on appropriate antimicrobial usage, leading to more effective prescribing practices. As part of the SENTRY Antimicrobial Surveillance Program (SENTRY, 1998), participants collected 50 consecutive UTI pathogens from patients hospitalized in 31 medical centers (26 in the United States and five in Canada) and forwarded subcultures to the coordinating center. Thirty-four antimicrobial agents were tested including two investigational compounds (quinupristin/dalfopristin [Q/D], gatifloxacin). The rank order of the 32 species identified during the study was: Escherichia coli (46.9%) > Enterococcus spp. (12.8%) > Klebsiella spp. (11.0%) > Pseudomonas aeruginosa (7.5%) > Proteus mirabilis (5.0%) > coagulase-negative staphylococci (CoNS; 3.4%). This pathogen rank order did not change from 1997 to 1998, but resistance patterns changed. Clonal spread of confirmed extended spectrum beta-lactamase-producing strains was not observed, but co-resistance was elevated for aminoglycosides, tetracyclines, sulfonamides, and fluoroquinolones. P. aeruginosa was most susceptible to amikacin (97.3%) > piperacillin +/- tazobactam (92.0-95.6%) > cefepime = imipenem (91.2%) > ceftazidime (85.8%). Fluoroquinolone resistance was greater in P. aeruginosa (24.8-39.8%) > P. mirabilis (5.3-13.3%) > Enterobacter spp. (6.7-8.9%) > Klebsiella spp. (4.2-7.8%) > E. coli (3.0-3.8%). Only 5% of enterococci were resistant to vancomycin. These results emphasize the need for continued surveillance studies for common infections which establish baseline resistance patterns by geographic areas, and have the potential to detect epidemics or direct local epidemiologic interventions.

Adolescent↗
PubMed2006

Antimicrobial resistance in nosocomial bloodstream infection associated with pneumonia and the value of systematic surveillance cultures in an adult intensive care unit.

OBJECTIVE: To study the occurrence of multiple-drug-resistant pathogens in nosocomial bloodstream infection associated with pneumonia. To evaluate prediction of multiple drug resistance by systematic surveillance cultures. DESIGN: A retrospective study of a prospectively gathered cohort. SETTING: Fifty-four-bed adult medical-surgical intensive care unit of a tertiary hospital. PATIENTS: One hundred twelve intensive care unit patients with nosocomial bloodstream infection associated with pneumonia from 1992 through 2001. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Concordance of blood cultures with prior surveillance culture was assessed. Surveillance cultures were taken routinely as thrice weekly urinary cultures and oral swabs, once weekly anal swabs, and thrice weekly tracheal aspirates in intubated patients. Tracheal surveillance cultures from 48 to 96 hrs before bloodstream infection and surveillance cultures from any site during the same intensive care unit episode but >or=48 hrs before bloodstream infection were evaluated separately. Forty-four bloodstream infections (39%) were caused by a multiple-drug-resistant pathogen. Multiple-drug-resistant pathogens were predicted by tracheal surveillance culture in 70% (concordant); in 15%, tracheal surveillance culture grew a multiple-drug-resistant pathogen not found in blood cultures (discordant). Multiple-drug-resistant pathogens were predicted by any surveillance culture in 88%, but these surveillance cultures grew additional multiple-drug-resistant pathogens not causing bloodstream infection in up to 46% of patients. In 86% of bloodstream infections, early (i.e., within 48 hrs) antibiotic therapy was appropriate. Patients were divided into four risk categories for multiple-drug-resistant bloodstream infection based on length of prior intensive care unit stay and prior antibiotic exposure. In patients with two risk factors, knowledge of surveillance cultures increased appropriateness of early antibiotic therapy from 75-79% to 90% (p<.05) while limiting use of broad-spectrum antibiotics such as antipseudomonal betalactams, fluoroquinolones, and carbapenems. CONCLUSIONS: In our intensive care unit, tracheal surveillance culture predicted multiple-drug-resistant etiology of bloodstream infection associated with pneumonia in 70% of patients but yielded discordant resistant pathogens in 15%. In the subgroup of patients with two risk factors for multiple-drug-resistant infection, incorporating results of surveillance cultures moderately contributed to adequacy of early antibiotic therapy while limiting antibiotic consumption.

Anti-Bacterial Agents↗
PubMed2006

Enterotoxigenic Escherichia coli colonization factor types collected from 1997 to 2001 in US military personnel during operation Bright Star in northern Egypt.

Operation Bright Star (OBS) is a biennial, multinational exercise in Egypt involving 15000 US troops. Consistent with past observations in deployed troops, diarrhea is the most significant cause of morbidity. Focused efforts are ongoing to develop vaccines against the most common pathogens affecting our troops. As part of these efforts, diarrhea surveillance was conducted during OBS to monitor pathogens associated with illness and to identify new vaccine targets. A retrospective review was conducted of prior studies with similar methods. Soldiers with diarrhea presenting to the OBS clinic provided a stool sample that was inoculated into Carey-Blair transport media. Within 3 days, the Cary-Blair tubes were transported to the Naval Medical Research Unit no. 3 in Cairo where bacterial culture was performed. As part of the evaluation, 5 Escherichia coli-like colonies were collected and tested for toxin production using the GM1-ELISA. Toxin-positive isolates were further tested for colonization factors (CF) by a dot-blot assay using a standardized panel of monoclonal antibodies against CFA/I, CS1-CS7, CS17, CS8 (CFA/III), CS12 (PCFO159), and CS14 (PCFO166). Enterotoxigenic E. coli (ETEC) was the most frequently isolated pathogen during each OBS from which data were collected. The rate of ETEC-associated diarrhea ranged from 22% to 58%. Over time, there were dramatic shifts in the frequency and distribution of CFs. Over the 5 years of study, an increasing number of ETEC isolates had no known CF identified, and in 2001, only 40% of ETEC was associated with known CFs. The most commonly identified CF was CS6. Diarrheal disease, particularly ETEC, continues to be a common malady among US military personnel deployed to Egypt. We have identified ETEC CF types, especially CS6, which should be considered potential vaccine candidates. However, despite intensive testing, CFs could not be identified in most of the ETEC isolated, highlighting the need for further studies to identify novel CFs and alternative vaccine targets.

Antibodies, Monoclonal↗
PubMed2003

Salmonella bloodstream infections: report from the SENTRY Antimicrobial Surveillance Program (1997-2001).

Salmonella spp. are significant bloodstream pathogens and are routinely monitored for antimicrobial resistance by the SENTRY Antimicrobial Surveillance Program. Six hundred and one bloodstream infection (BSI) isolates of Salmonella spp., collected over a 5-year period (1997-2001) were tested for their susceptibility against 20 antimicrobial agents, comparing year and geographical region. Salmonella enterica serotype Typhi was the most frequently identified 'species' (43% of identified strains), although 'unspeciated' strains predominated overall (54.2%). The rank order for six selected drugs tested by their MIC(90) values and percentage susceptibility was: ceftriaxone (< or =0.25 mg/l; 99.5% susceptible)>ciprofloxacin (0.12 mg/l; 99.3%)> trimethoprim/sulphamethoxazole (< or =0.5 mg/l; 92.7%)>amoxycillin/clavulanate (16 mg/l; 89.7%)>ampicillin (>16 mg/l; 81.0%)>tetracycline (>8 mg/l; 79.4%). Most isolates remained highly susceptible to all 20 agents examined, with the exception of Salmonella Typhimurium (only 35.3% susceptible to tetracycline, 41.2% to ampicillin, and 61.8% to amoxycillin/clavulanate). DT104 resistance phenotypes were noted in 3.4 and nearly 60.0% of unspeciated Salmonella and S. Typhimurium, respectively. Unexpectedly, the highest overall susceptibility rates were recorded in Latin America. Fluoroquinolone resistance was observed and nalidixic acid screening MICs (< or =8 mg/l) predicted full susceptibility to ciprofloxacin. Five-year results from the SENTRY Program show no clear trend toward greater resistances in Salmonella spp. BSIs for the commonly used antimicrobial classes. With the exception of S. Typhimurium DT104, most Salmonella spp. remain highly susceptible to the tested antimicrobials that maybe utilized for Salmonella BSI.

Bacteremia↗
PubMed2026

Systematic review on genomic insights into antimicrobial resistance in ESKAPE pathogens.

BACKGROUND: Antimicrobial resistance (AMR) is a major global public health threat. ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pose a major threat owing to resistance to last-line antibiotics. Genomic surveillance is crucial to understanding global and regional antimicrobial resistance genes (ARGs) in AMR transmission. AIM: This systematic review synthesised global genomic evidence to identify global and region-specific ARGs distribution among ESKAPE pathogens. METHODS: Following PRISMA guidelines, studies published January 2019 to December 2024 were identified from PubMed, Google Scholar, and Web of Science. Eligible studies reported genomic characteristics and resistance patterns of one or more ESKAPE pathogens from any source. RESULTS: Seventy-seven studies were included, with most originating from Asia, followed by Europe and Africa. Clinical isolates predominated K. pneumoniae was the most frequently investigated pathogen, followed by S. aureus, P. aeruginosa, and A. baumannii. The most reported resistance genes were blaCTX-M, blaNDM, and blaSHV. Distinct regional patterns of antimicrobial resistance gene (ARG) distribution were observed, with tetracycline and quinolone resistance genes prevailing in Africa and South America, and blaOXA variants dominating in Asia and Europe. Region-specific ARG patterns were identified through descriptive synthesis and comparative analysis of study-reported frequencies. CONCLUSION: This review provides a synthesised global map of ARG distribution in ESKAPE pathogens, highlighting surveillance gaps in underrepresented regions and non-clinical settings. Addressing these gaps will support targeted genomic surveillance and stewardship programmes. WHAT THIS STUDY ADDS: This study contributes to the body of knowledge by mapping global and regional antimicrobial resistance gene patterns in ESKAPE pathogens, identifying key surveillance gaps and informing targeted AMR monitoring and stewardship strategies.

ESKAPE pathogens↗
PubMed2005

A multicenter hospital surveillance of invasive Streptococcus pneumoniae, Puerto Rico, 2001.

Although antimicrobial resistance to Streptococcus pneumoniae has been increased dramatically worldwide, there is limited information of pattern of susceptibility for this pathogen in Puerto Rico. Hospital-based surveillance for invasive pneumococcal infections was begun among 38 hospitals island-wide in Puerto Rico from January to December, 2001. One hundred ninety-two cases of invasive pneumococcal disease were identified. Of the 177 isolates available for susceptibility testing, 50.3% were susceptible to penicillin and 49.7% were nonsusceptible (intermediate (I) and resistance (R)) (19.2% I, 30.5% R). Resistance was documented for expanded spectrum cephalosporins and macrolides. All isolates were susceptible to vancomycin. Diabetes, cardiovascular disease, smoking and bronchial asthma were the most common risk factors associated with invasive pneumococcal disease of the adult population. Bronchial asthma was the most common disease in the pediatric population with a fatality rate of 21%. There was no increased mortality detected among patients infected with penicillin resistant strains. Most of the isolates serotypes are represented in the 23-valent polysaccharide vaccine (78%) and 7-valent conjugate vaccine (62%). Penicillin-resistant isolates (47%) were 14, 19F, 6B, 6A, 9V, 23F, 19A and 35B serotype. Our data indicated a high prevalence for drug-resistant strains of S. pneumoniae in Puerto Rico. Continue surveillance for this common but serious pathogen is needed. Asthma is an important risk factor for pneumococcal disease. The pneumococcal vaccine should be recommended for all age groups with this risk factor.

Adolescent↗
PubMed2026

H5N1 Clade 2.3.4.4b Infections in Domestic Cats During an Avian Influenza Outbreak in Italy: Implications for One Health Surveillance.

BACKGROUND: H5Nx goose/Guangdong (Gs/GD) lineage highly pathogenic avian influenza (HPAI) viruses pose a significant public health threat due to their global spread, mutation accumulation, and expanding host range. The descendant clade 2.3.4.4b has been causing widespread infections in birds and increasing spillover events in mammals. METHODS: This report documents the first fatal case of highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b infection in a domestic cat in Italy, detected in early January 2025. The cat (CAT 1) resided on a backyard poultry farm experiencing a high pathogenicity avian influenza outbreak and succumbed rapidly following the onset of respiratory signs. A second exposed cat (CAT 2) developed clinical disease without fatal outcome. Comprehensive outbreak investigations were conducted, including pathological, serological, molecular analyses, and genomic characterization. RESULTS: Pathological examination of CAT 1 revealed acute necrotizing bronchointerstitial pneumonia, non-suppurative meningoencephalitis, and disseminated foci of hepatic necrosis. Interestingly, the PB2-E627K mutation associated with mammalian virus adaptation was observed in the feline viral isolate compared to avian isolates. Such polymerase complex mutations are key determinants of host range and increase pathogenicity in mammals. CAT 2 from the same farm tested negative for AIV genome detection but subsequently seroconverted for antibodies against NPA, H5, and N1. CONCLUSION: Sharing these findings is crucial for surveillance aimed at enabling early identification of increased risks to human and animal health, preventing cross-species viral transmission and mitigating the risk of potential spillover events.

Animals↗
PubMed2006

What to think if the results of the National Institutes of Health randomized trial of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus control measures are negative (and other advice to young epidemiologists): a review and an au revoir.

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) infections continues to rise in National Nosocomial Infections Surveillance system hospitals, and these pathogens are reportedly causing more than 100,000 infections and many deaths each year in US healthcare facilities. This has led some to insist that control measures are now urgently needed, but several recent articles have suggested that isolation of patients does not work, is not needed, or is unsafe, or that a single cluster-randomized trial could be used to decide such matters. At least 101 studies have reported controlling MRSA infection and 38 have reported controlling VRE infection by means of active detection by surveillance culture and use of isolation for all colonized patients in healthcare settings where the pathogens are epidemic or endemic, in academic and nonacademic hospitals, and in acute care, intensive care, and long-term care settings. MRSA colonization and infection have been controlled to exceedingly low levels in multiple nations and in the state of Western Australia for decades by use of active detection and isolation. Studies suggesting problems with using such data to control MRSA colonization and infection have their own problems, which are discussed. Randomized trials are epidemiologic tools that can sometimes provide erroneous results, and they have not been considered necessary for studying isolation before it is used to control other important infections, such as tuberculosis, smallpox, and severe acute respiratory syndrome. No single epidemiologic study should be considered definitive. One should always weigh all available evidence. Infection with antibiotic-resistant pathogens such as MRSA and VRE is controllable to a low level by active detection and isolation of colonized and infected patients. Effective measures should be used to minimize the morbidity and mortality attributable to these largely preventable infections.

Cross Infection↗
PubMed2002

Geographic variations in garenoxacin (BMS284756) activity tested against pathogens associated with skin and soft tissue infections: report from the SENTRY Antimicrobial Surveillance Program (2000).

The antimicrobial activity of garenoxacin, a des-(6)F quinolone (formally BMS284756 and T-3811), was evaluated against 2,537 skin and soft tissue infection (SSTI) isolates from the SENTRY Antimicrobial Surveillance Program. Strains isolated in 2000 from Europe, North and Latin America were tested at a central laboratory using reference broth microdilution methods. The rank order of the seven most frequent SSTI pathogens was: Staphylococcus aureus (39.9%), Pseudomonas aeruginosa (12.1%), Escherichia coli (9.7%), Enterococcus spp. (7.7%), Klebsiella spp. (5.8%), Enterobacter spp. (5.6%) and coagulase-negative staphylococci (CoNS; 4.2%). Garenoxacin exhibited a four-fold greater activity (MIC(90), 0.06 microg/ml) compared to levofloxacin (MIC(90), 0.25 microg/ml) against oxacillin-susceptible S. aureus; and oxacillin-resistant staphylococci were more susceptible to garenoxacin (>/=90.5%) at </=4 microg/ml than ciprofloxacin or levofloxacin. Enterococcus spp. were more susceptible to garenoxacin and gatifloxacin (MIC(50), 0.5 microg/ml) than ciprofloxacin or levofloxacin (MIC(50), 2 microg/ml). All tested quinolones inhibited 64.7 to 69.7% of P. aeruginosa isolates, and the rank order of potency slightly favored ciprofloxacin (MIC(50), </=0.25 microg/ml). Similar susceptibility rates for the four quinolones were observed against E. coli (85.8-87.0%), Enterobacter spp. (90.8-94.3%) and Klebsiella spp. (89.8-95.2%) with the greatest levels of resistance recorded in Latin America for E. coli and Enterobacter spp. The occurrence of extended spectrum beta-lactamase-producing isolates (predominantly K. pneumoniae) was documented in all three monitored regions (Latin America > Europe > North America). Continued development of garenoxacin as a treatment of pathogens that commonly cause SSTIs appears to be warranted.

Anti-Infective Agents↗
PubMed2001

Human cytomegalovirus and natural killer-mediated surveillance of HLA class I expression: a paradigm of host-pathogen adaptation.

Among various strategies to evade the host immune response, some viruses like human cytomegalovirus (HCMV) interfere with surface MHC class I expression and antigen presentation to T lymphocytes. The ability of natural killer (NK) cells to detect MHC class I molecules through inhibitory receptors can be envisaged as an adaptation of the immune system for responding to such pathological alterations. To fulfil that role, rodents use members of the Ly49 C-type lectin superfamily, whereas primates employ killer immunoglobulin-like receptors and the immunoglobulin-like transcript 2/leucocyte immunoglobulin-like receptor-1 receptor. CD94/NKG2 lectin-like heterodimers represent the most conserved receptor system for MHC class I molecules; by interacting with human HLA-E or murine Qa-1b, CD94/NKG2A inhibitory receptors broadly probe the biosynthesis pathway of other class I molecules. Reciprocally, HCMV has developed mechanisms to evade the NK response while modulating HLA class Ia expression. The ability of HCMV to maintain surface levels of HLA-E and to express an HLA class I surrogate (UL18) are herein discussed in the context of the interplay with human NKR systems.

Adaptation, Physiological↗
PubMed2003

Antibacterial resistance of community-acquired respiratory tract pathogens recovered from patients in Latin America: results from the PROTEKT surveillance study (1999-2000).

PROTEKT (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin) is a global surveillance study established in 1999 to monitor antibacterial resistance of respiratory tract organisms. Thirteen centers from Argentina, Brazil and Mexico participated during 1999-2000; they collected 1806 isolates (Streptococcus pneumoniae 518, Haemophilus influenzae 520, Moraxella catarrhalis 140, Staphylococcus aureus 351, S. pyogenes 277). Overall, 218 (42.1%) of the S. pneumoniae isolates had reduced susceptibility to penicillin, 79 (15.3%) were penicillin-resistant and 79 (15.3%) were erythromycin-resistant. Mexico had the highest prevalence of penicillin (76.5%) and erythromycin (31.2%) resistance. Of 77 erythromycin-resistant S. pneumoniae tested for resistance genotype, 43 possessed mef(A), 33 possessed erm(B) and 1 possessed both erm(B) and mef(A) mechanism. All S. pneumoniae isolates were fully susceptible to telithromycin, linezolid, teicoplanin and vancomycin. Among H. influenzae isolates, 88 (16.9%) produced beta-lactamase, ranging from 11% (Brazil) to 24.5% (Mexico). Among M. catarrhalis isolates, 138 (98.6%) produced beta-lactamase. Twenty-four (8.7%) of the S. pyogenes isolates were erythromycin-resistant; resistance being attributable to mefA (n=18), ermTR (n=5) and ermB (n=1). All H. influenzae, M. catarrhalis and S. pyogenes were fully susceptible to telithromycin. Methicillin resistance was found in 26.5% of the S. aureus isolates (Argentina 15%; Mexico 20%; Brazil 31.3%). Telithromycin was effective against 97.7% of methicillin-susceptible isolates. PROTEKT confirms that antibacterial resistance is an emerging problem in Latin America. The previously reported high levels of pneumococcal resistance to the beta-lactam and macrolides were exceeded. New agents that do not induce resistance or that exert low selective pressure, e.g. telithromycin, are essential to safeguard future antibacterial efficacy.

Anti-Bacterial Agents↗
PubMed2001

[Laboratory system for networks in infection control].

The goals of a surveillance for nosocomial infections are to observe the magnitude and characteristics of the infections, and to plan and evaluate policies and guidelines of infection control. In clinical laboratory, although it is most important to detect their causative pathogens, further to provide the surveillance study as a multicenter. Actually, we have just started an infection control room in our hospital. Thus this room may present various informations about infection and contribute to the networks with the area community.

Cross Infection↗
PubMed2000

Frequency of occurrence and antimicrobial susceptibility patterns for pathogens isolated from latin american patients with a diagnosis of pneumonia: results from the SENTRY antimicrobial surveillance program (1998).

The correct empiric choice of antimicrobial therapy in the treatment of pneumonia in hospitalized patients has established itself as a major therapeutic challenge to clinicians. Selection of an inappropriate antimicrobial agent could lead to increased rates of mortality and morbidity. Characteristics of pathogens responsible for this infection such as species prevalence, overall antimicrobial resistance rates, and mechanisms of detected resistance could serve as an invaluable resource to clinicians in making such therapeutic selections. This report addresses the aforementioned problems/needs by analysis of 712 strains isolated from the lower respiratory tract of patients hospitalized with a diagnosis of pneumonia in 10 Latin American medical centers in the SENTRY Antimicrobial Surveillance Program (1998). The four most frequently isolated pathogens (no/% of total) were: Pseudomonas aeruginosa (191/26.8%), Staphylococcus aureus (171/24.0%), Klebsiella spp. (86/12.1%), and Acinetobacter spp. (75/10.5%); representing nearly 75.0% of all isolates. More than 40 antimicrobial agents (23 reported) were tested against these isolates by reference broth microdilution methodology, and susceptibility profiles were established. The nonfermentative Gram-negative bacteria (P. aeruginosa and Acinetobacter spp.) exhibited high levels of resistance to the agents tested. Amikacin (77.5% susceptible) was the most active drug tested against P. aeruginosa 50.0% against the Acinetobacter spp. isolates. Based on published interpretive criteria, over 22.0% of the Klebsiella spp. and 12.5% of the Escherichia coli were classified as extended spectrum beta-lactamase (ESBL) producers. Of the cephalosporin class compounds tested against the Klebsiella spp. and E. coli isolates, cefepime demonstrated the highest rates of susceptibility (84.9% and 91.7%, respectively). This compound also fared well against the Enterobacter spp. isolates, inhibiting 88.2% of the isolates tested, many of which were resistant to ceftazidime and ceftriaxone. Resistance to oxacillin among the S. aureus isolates was nearly 50. 0%, with vancomycin, teicoplanin, and the streptogramin combination quinupristin/dalfopristin inhibiting all isolates. Several clusters of multiply resistant organisms were also observed, and further characterization by ribotyping and pulsed-field gel electrophoresis established possible patient-to-patient spread. The results of this study indicate that rates of resistance among respiratory tract pathogens continue to rise in Latin America, with specific concerns for the high prevalence of nonfermentative Gram-negative bacteria isolated, oxacillin resistance rates in S. aureus, and the epidemic dissemination of multiply-resistant strains in several medical centers. International surveillance programs (SENTRY) should assist in the control of escalating antimicrobial resistance in this geographic area.

Anti-Bacterial Agents↗
PubMed2005

The Alexander Project: the benefits from a decade of surveillance.

The Alexander Project, initiated in 1992 as an international, multicentre, longitudinal surveillance study of antimicrobial susceptibility among common respiratory pathogens, has been pivotal in defining the role of global surveillance. At the time, there were few studies in which data were collected in a way that allowed meaningful comparisons to be made between studies, locations or over time. The project instituted the use of a central laboratory and standardized methods for the collection of isolates and determination of susceptibility, and this was continued with the addition of two further reference laboratories. Data from the study have provided a resource for measuring trends in the susceptibility patterns of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis at country, regional and global levels. Determination and publication of quantitative MICs enabled detailed assessment of changes in susceptibility distributions and assessment of microbiological and potential clinical susceptibility using different breakpoints, including those based on pharmacokinetic/pharmacodynamic parameters. Comparisons of antimicrobial usage patterns and resistance prevalences over time allowed hypotheses to be examined with respect to the role of quantity and type of antimicrobial use in the selection and spread of resistance. The resulting collection of isolates has provided a valuable resource for molecular studies into the evolution of resistance over time and location; a substantial proportion of this collection is now in the public domain. This paper reviews the 10 years of the Alexander Project and the benefits it has brought to an understanding of the evolution of antibacterial resistance in community respiratory bacteria.

Anti-Bacterial Agents↗
PubMed1998

Microbiology of acute otitis media in Costa Rican children.

BACKGROUND: Because of the increasing number of resistant middle ear pathogens reported from different centers worldwide, an active surveillance of the microbiology and susceptibility pattern of middle ear pathogens is required for proper antimicrobial recommendations among different regions of the world. OBJECTIVE: To study the microbiology and susceptibility pattern of middle ear pathogens obtained from Costa Rican children with acute otitis media. METHODS: Between 1992 and 1997 a diagnostic tympanocentesis was performed in 398 Costa Rican patients with acute otitis media. Middle ear fluid was obtained for culture and minimal inhibitory concentrations were determined by the E-test technique in those isolates obtained between October, 1995, and January, 1997. RESULTS: The most common pathogens cultured were Streptococcus pneumoniae (30%), Haemophilus influenzae (14%), Staphylococcus aureus (4%) and Streptococcus pyogenes (4%). Moraxella catarrhalis was uncommon. Beta-lactamase production was low (3.7%) among the H. influenzae isolates but frequent among the Staphylococcus aureus (57.1%) and M. catarrhalis (100%) strains. Overall 9 of 46 S. pneumoniae isolates (19.6%) exhibited decreased susceptibility to penicillin of which 8 isolates (17.4%) showed intermediate and one strain (2.2%) high level resistance. Among the penicillin-susceptible S. pneumoniae isolates, susceptibility to the following antimicrobials was: 81%, azithromycin; 89%, clarithromycin; and 100%, ceftriaxone and trimethoprim-sulfamethoxazole (TMP-SMX). Among the penicillin-resistant S. pneumoniae isolates the percentage of susceptible strains was 89% for azithromycin, clarithromycin and ceftriaxone and 67% for TMP-SMX. CONCLUSIONS: Based on this microbiologic information the agents considered first line drugs in the treatment of acute otitis media in Costa Rica remain amoxicillin or TMP-SMX.

Acute Disease↗
PubMed1997

Problems of microbial zoonoses in Hungary. (A review).

Hungarian data of 36 zoonotic diseases are summarized. These illnesses cause problems not only for health, public health and veterinary health services but for the society and their importance has increased. Changing character of an old pathogen (Salmonella enteritidis PT4) resulted in new epidemiological situation. The number of cases of food-borne zoonotic diseases has rapidly grown. The number of pets has elevated and in consequence the possibility of an infection of owners, breaders, sellers and other persons has also grown. Growing number of HIV positive patients as well as ill persons treated with immunosuppressive drugs increases the importance of opportunistic zoonotic pathogens (Cryptosporidium, Toxoplasma). The most effective and less expensive way to prevent an exposed population is the active immunization (BCG, tetanus, tick-borne encephalitis). Active immunization of animals can also reduce probability of human infections and economic losses (leptospirosis, rabies). In special cases it is advised to perform eradication programmes to get pathogenic-free domestic animals (brucellosis, bovine tuberculosis, salmonellosis, campylobacteriosis). Permanent surveillance is obligatory to recognize changing nature of pathogens, alteration of epidemiological situation and to identify areas for further research. Continuous education of population in general and special teaching of risky groups are very important for an effective prevention.

Animals↗