Papers by Angela Famiglietti
Antimicrobial agents and chemotherapy, Mar 28, 2016
Ceftazidime-avibactam is a novel β-lactam/β-lactamase inhibitor with activity against carbapenem-... more Ceftazidime-avibactam is a novel β-lactam/β-lactamase inhibitor with activity against carbapenem-resistant Enterobacteriaceae (CRE) that produce Klebsiella pneumoniae carbapenemase (KPC). We report the first cases of ceftazidime-avibactam resistance to develop during treatment of CRE infections, and identify resistance mechanisms. Ceftazidime-avibactam resistant K. pneumoniae emerged in three patients after ceftazidime-avibactam treatment for 10-19 days. Whole genome sequencing (WGS) of longitudinal ceftazidime-avibactam susceptible and resistant K. pneumoniae isolates was used to identify potential resistance mechanisms. WGS identified mutations in plasmid-borne blaKPC-3, which were not present in baseline isolates. blaKPC-3mutations emerged independently in isolates of a novel sequence type-258 sub-lineage and resulted in variant KPC-3 enzymes. The mutations were validated as resistance determinants by measuring minimum inhibitory concentrations (MICs) of ceftazidime-avibactam and...
PubMed, 1997
Community-acquired pneumonia (CAP) affects approximately 1% of the population annually. Initial a... more Community-acquired pneumonia (CAP) affects approximately 1% of the population annually. Initial antimicrobial therapy is most often empirical. Guidelines designed in other countries for the empirical management of CAP are not recommended for use in Argentina. Studies from other countries were considered together with unpublished local data to define the potential etiologic microorganisms and their antimicrobial susceptibility. Recommended diagnostic tests, groups of patients for different therapies and hospitalization criteria were defined. Severe CAP requiring intensive care was distinguished from the rest because of its distinct spectrum of etiologic agents and its high mortality, requiring a more focused therapy. Age, coexisting conditions and severity of illness were taken into account in the election of therapy.
International Journal of Infectious Diseases, 2000
Introduction: A national surveillance program (SIR) was introduced in 1996 in Argentina by the An... more Introduction: A national surveillance program (SIR) was introduced in 1996 in Argentina by the Antimicrobial Committee of the Argentinean Society for Microbiology to assess bacterial resistance, The present study reports the rates of nosocomial bacterial resistance found by this program. R/lethods: A 2-month point-prevalence study was conducted twice yearly (i.e., April-May and October-November) from 1996 to 1998, by 27 Argentinean centers. Susceptibility testing was carried out by the disk diffusion method following the National Committee for Clinical Laboratory Standards guidelines. Results: In all, 6343 isolates recovered from 5603 inpatients (248-hr hospitalization) were included. Methicillin resistance was 58% and 56% in Staphylococcus aureus and coagulase-negative staphylococci (CNS), respectively. Although no vancomycin resistance was found in staphylococci, 2% and 8% of the S. aureus and CNS strains, respectively, proved resistant to teicoplanin. No ampicillin resistance was displayed by fnterococcus faecalis. High-level gentamicin and streptomycin resistance in enterococci were 33% and 37%, respectively. Acquired glycopeptide resistance in enterococci emerged in 1997 (2%). lmipenem resistance in Acinetobacter spp and Pseudomonas aeruginosa was 9% and 21%, respectively. Among Enterobacteriaceae, 1% and 5% of the Klebsiella pneumoniae and Enterobacter cloacae isolates, respectively, proved resistant to imipenem. Ceftazidime and cefepime resistance was found in 63% and 33% of the E. cloacae strains.
Journal of Chemotherapy, Sep 18, 2020
A rapid colorimetric method, the Andrade screening antimicrobial test, was compared with the E-te... more A rapid colorimetric method, the Andrade screening antimicrobial test, was compared with the E-test method to detect ceftazidime/avibactam (CZA) resistance in carbapenem resistant Enterobacterales clinical isolates. A 106 non-duplicated isolates (86 susceptible and 20 resistant to CZA) were chosen for validation. The sensitivity and specificity were 100%. This method investigates CZA resistance regardless of the resistance mechanism involved. It represents an economical and easy technique that can be applied to routine microbiology laboratories. It allows the detection of CZA resistance at 3 hours of incubation and consequently, the early implementation of accurate therapeutic interventions.
Revista De Microbiologia, 1998
Korean Journal of Parasitology, Apr 30, 2016
The aim of this study was to evaluate different methods for Trichomonas vaginalis diagnosis durin... more The aim of this study was to evaluate different methods for Trichomonas vaginalis diagnosis during pregnancy in order to prevent maternal and perinatal complications. A total of 386 vaginal exudates from pregnant women were analyzed. T. vaginalis was investigated by 3 types of microscopic examinations direct wet mount with physiologic saline solution, prolonged May-Grunwald Giemsa (MGG) staining, and wet mount with sodium-acetate-formalin (SAF)/methylene blue method. PCR for 18S rRNA gene as well as culture in liquid medium were performed. The sensitivity and specificity of the microscopic examinations were evaluated considering the culture media positivity or the PCR techniques as gold standard. The frequency of T. vaginalis infection was 6.2% by culture and/or PCR, 5.2% by PCR, 4.7% by culture, 3.1% by SAF/methylene blue method and 2.8% by direct wet smear and prolonged MGG staining. The sensitivities were 83.3%, 75.0%, 50.0%, and 45.8% for PCR, culture, SAF/methylene blue method, and direct wet smear-prolonged MGG staining, respectively. The specificity was 100% for all the assessed methods. Microscopic examinations showed low sensitivity, mainly in asymptomatic pregnant patients. It is necessary to improve the detection of T. vaginalis using combined methods providing higher sensitivity, such as culture and PCR, mainly in asymptomatic pregnant patients, in order to prevent maternal and perinatal complications.
Diagnostic Microbiology and Infectious Disease, Feb 1, 2007
Non-enterococcal Gram-positive bacteria that are intrinsically vancomycin-resistant have been inf... more Non-enterococcal Gram-positive bacteria that are intrinsically vancomycin-resistant have been infrequently isolated in association with serious infections. However, well-documented infections have lately been reported with increasing frequency. Because these organisms may be pathogens, we tested the MICs of 19 antimicrobial agents by the agar dilution method for predicting susceptibility. The activity of these antimicrobial agents was assessed against 28 strains (Lactobacillus rhamnosus, 6; Lactobacillus acidophilus, 1; Lactobacillus casei, 1; Lactobacillus fermentum, 2; Lactobacillus brevis, 1; Lactobacillus plantarum, 1; Weissella confusa, 2; Leuconostoc mesenteroides, 7; Leuconostoc lactis, 4; Pediococcus acidilactici, 2; Pediococcus pentosaceus, 1), isolated from clinical specimens in an Argentinian university hospital from 1997 to 2003. The MICs of penicillin for 67% of the Lactobacillus strains and 100% of the Leuconostoc spp. and Pediococcus spp. strains tested were in the 0.25-2 microg/mL range. Erythromycin was the most active antimicrobial overall. Multiresistance was observed in 2 strains (Lactobacillus rhamnosus, 1; Lactobacillus plantarum, 1).
PubMed, Dec 6, 2005
The aim of this study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isol... more The aim of this study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from different infectious sites of hospitalized patients at two university hospitals. Fourteen isolates were analyzed by repetitive sequence based PCR (Rep-PCR), randomly amplified polymorphic DNA assay (RAPD-PCR), and pulsed-field gel electrophoresis (PFGE). We found that a prevalent clone of MRSA, susceptible to rifampin, minocycline, and trimethoprim/sulfamethoxazole (RIF(s), MIN(s), TMS(s)) was present in both hospitals in replacement of the multiresistant MRSA South American clone, previously described in these hospitals. The staphylococcal chromosomal cassette (SCCmec) type I element was detected in this new clone.
Revista Argentina De Microbiologia, 2019
Revista Argentina De Microbiologia, 2016
Actividad in vitro de ampicilina-ceftriaxona frente a aislamientos de Enterococcus faecalis recup... more Actividad in vitro de ampicilina-ceftriaxona frente a aislamientos de Enterococcus faecalis recuperados de infecciones invasivas
Microbial Drug Resistance, May 1, 2022
Access microbiology, Aug 1, 2020
Clostridium ramosum is an enteric anaerobic, endospore-forming, gram-positive rod with a low GC c... more Clostridium ramosum is an enteric anaerobic, endospore-forming, gram-positive rod with a low GC content that is rarely associated with disease in humans. We present a case of C. ramosum bacteraemia. To the best of our knowledge, this is the second case of C. ramosum bacteraemia in an elderly patient presenting with fever, abdominal pain and bilious emesis. We highlight the Gram stain variability, the lack of visualization of spores and the atypical morphology of the colonies that showed C. ramosum in a polymicrobial presentation that initially appeared to show monomicrobial bacteraemia. The microorganism was rapidly identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We present a comprehensive literature review of 32 cases of clinical infections by C. ramosum in which we describe, if available, sex, age, clinical symptoms, predisposing conditions, other organisms present in the blood culture, other samples with C. ramosum , identification methodology, treatment and outcome.
Journal of Infection, 2012
We read with interest the paper by Li and colleagues concerning colistin hetero-resistance in Aci... more We read with interest the paper by Li and colleagues concerning colistin hetero-resistance in Acinetobacter baumannii clinical isolates. The incidence of colistin-heteroresistance is still not well known due to its difficult detection. Moreover, its clinical impact has only been discussed in our previous report and in a communication of David. In a recent review of patients with meningitis due to A. baumannii treated with colistin, heteroresistant isolates have not been described. The aim of the present work is to report our experience regarding the clinical impact of colistin-heteroresistance in post neurosurgical meningitis caused by A. baumannii. Seven isolates were recovered from two cases (patients 1 and 2) of A. baumannii colistin heteroresistant in post neurosurgical meningitis were detected in the intensive care unit of Hospital de Clinicas Jose de San Martin of Buenos Aires city during the period 2004e2009. The selection intra-treatment with colistin of A. baumannii colistinresistant was analyzed. Strains were identified by phenotypic tests and genomospecies was determined by ARDRA (Amplified ribosomal DNA restriction analysis). Minimal inhibitory concentrations (MICs) to colistin (against the resistant subpopulations and the original strains) and the other antimicrobials (ampicillinesulbactam, ceftriaxone, ceftazidima, imipenem, meropenem, amikacin, gentamicin and levofloxacin) were performed by dilution method in cation-adjusted MuellerHinton agar and interpreted according to the Clinical and Laboratory Standards Institute. Pulsed-field electrophoresis (PFGE) was performed with ApaI as described previously. Population analysis profiles (PAPs) were determined according to a previous report. Timeekill studies were performed twice and thus, results were analyzed by using mean colony count values from the duplicate plates for each isolate, with the following concentrations: colistin sulfate: 4,8,12 and 80 MIC and rifampicin 4 mg/ ml. This study was performed with the colistin susceptible heteroresistant isolates from each patient (Ab86 and
InTech eBooks, Mar 21, 2012
Journal of Medical Microbiology, Jul 1, 2020
Introduction. The therapeutic options to treat Acinetobacter baumannii infections are very limite... more Introduction. The therapeutic options to treat Acinetobacter baumannii infections are very limited. Aim. Our aim was to evaluate the activity of sulbactam combined directly with avibactam or the ampicillin-sulbactam/ceftazidime-avibactam combination against extensively drug-resistant A. baumannii isolates. Methodology. Extensively drug-resistant A. baumannii isolates (n=127) collected at several South American hospitals were studied. Synergy with the sulbactam/avibactam combination was assessed in all isolates using the agar dilution method. Avibactam was used at a fixed concentration of 4 mg l−1. A disc diffusion synergy test was also performed. Synergy by a time-kill experiment was performed in a selected isolate. Results. Synergy with sulbactam/avibactam was demonstrated in 124 isolates and it showed MIC values ≤4 mg l−1. This synergy was not detected in the three New Delhi metallo-β-lactamase-harbouring isolates. Similar results were observed with the disc diffusion synergy test of ampicillin-sulbactam/ceftazidime-avibactam. In the time-kill experiments, sulbactam/avibactam showed a rapid synergistic and bactericidal activity in ampicillin-sulbactam-resistant isolates. Conclusions. This study demonstrated that the sulbactam/avibactam combination displayed synergistic activity against A. baumannii isolates. This synergy was observed when both inhibitors were also used as part of the commercially available combinations: ampicillin-sulbactam and ceftazidime-avibactam.
Journal of Medical Microbiology, Oct 18, 2016
One hundred and twenty-six epidemiologically sequential, unrelated, carbapenem-resistant Acinetob... more One hundred and twenty-six epidemiologically sequential, unrelated, carbapenem-resistant Acinetobacter baumannii isolates from nine hospitals in six countries of South America were collected between July 2013 and June 2014. Genes coding for Ambler class D and B carbapenemases were sought by PCR. All isolates were typed using the 3-locus sequence typing and bla OXA-51-like sequence-based typing techniques. The bla OXA-23 gene was recovered in all the participating hospitals and in all the isolates of seven of nine medical centres. The bla OXA-72 gene was only recovered in the two medical centres from Guayaquil city, Ecuador. Trilocus sequence typing revealed the presence of sequence groups SG2, SG4 and SG5. bla OXA-51-like sequence-based typing revealed the presence of bla OXA-132 , bla OXA-65 , bla OXA-69 and bla OXA-64. Our results showed that the population of carbapenem-resistant A. baumannii in South America was principally associated with ST79, ST25 and ST15 (92 %) and harboured the bla OXA-23 gene mainly. CC2 was not detected.
Revista Argentina De Microbiologia, Jul 1, 2018
Carbapenem resistance in gram-negative bacteria by production of carbapenemases is one of the mos... more Carbapenem resistance in gram-negative bacteria by production of carbapenemases is one of the most challenging issues regarding healthcare worldwide. We review the epidemiology and prevalence of carbapenemases in carbapenem-resistant Acinetobacter baumannii isolates from Latin American countries. High resistance rates to antimicrobial agents, particularly to carbapenems, are observed in this region. OXA-23 is the most widely disseminated class D-carbapenemase; it is present in all the countries of the region and is frequently associated to endemic clones CC113/CC79, CC104/CC15, CC110/ST25 and CC109/CC1. The emergence of OXA-72 and NDM-1 represents a novel finding which is observed simultaneously and without clonal relatedness in different countries, some of which are distant from one another, whereas OXA-143 is only present in Brazil. Further collaborative intraregional studies would provide a better understanding of these issues in most of the countries and thus, policies to control the spread of these isolates could be implemented.
Antibiotics, Feb 11, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Antimicrobial Agents and Chemotherapy, Jul 1, 2016
Journal of Antimicrobial Chemotherapy, Apr 16, 2019
Background: SME serine carbapenemase are increasingly reported, especially from North and South A... more Background: SME serine carbapenemase are increasingly reported, especially from North and South America. Here, we describe an SME-4-producing Serratia marcescens (SME-Sm) clinical isolate from Argentina and compared its genome with other SME-Sm recovered from different countries. Methods: S. marcescens isolates were characterized by WGS using Illumina technology, susceptibility testing and MIC determination. Carbapenemase activity was revealed by biochemical tests based on imipenem hydrolysis. Additionally, WGS of S. marcescens containing or not bla SME genes were retrieved from Genbank database. A whole-genome phylogenetic analysis based on non-recombinant core SNPs was inferred for S. marcescens complete genomes and for those encoding any bla SME variant. Results: S. marcescens 163 was resistant to temocillin, aztreonam and carbapenems, remaining susceptible to expanded-spectrum cephalosporins. Analysis of WGS data of S. marcescens 163 revealed a genome of 5,139,329 bp, and a chromosomally-encoded class A bla SME-4 carbapenemase gene, which was located on a genomic island closely related to SmarG1-1 of S. marcescens N11-02820. The comparison of the S. marcescens genomes revealed that all SME-Sm isolates possess this genomic island inserted at the same loci, form a well-defined subcluster of cluster I of S. marcescens clade 1, while S. marcescens 163 belonged to clade 2, suggesting that the SME-encoding genomic island may have been transferred between isolates from different clades. Conclusions: To the best of our knowledge this is the first report of a SME-4-Sm from Argentina. Bla SME-4 gene is located on a SmarG1-1-like genomic island. The genome of S. marcescens 163 belongs to clade 2, unlike all the other SME-Sm isolates that belong to a subcluster of clade I.
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Papers by Angela Famiglietti