Similar Resistance Patterns Research Articles

Drug resistance in patients with tuberculous pleural effusions.

To summarize data regarding categories, detection methods, prevalence and patterns of drug resistance among patients with tuberculous pleural effusion (TPE) and to comment on the management of suspected drug-resistant TPE. Pleural and pulmonary tuberculosis (TB) present similar patterns of drug resistance. Approximately 10% and 6-10% of pleural Mycobacterium tuberculosis isolates are resistant to at least one first-line anti-TB drug or at least isoniazid, respectively. The prevalence of multidrug-resistant-pleural and extensively drug-resistant-pleural TB is 1-3% and 0-1%, respectively. Although guidelines suggest the empirical standard anti-TB regimen (i.e. 2 months of isoniazid, rifampicin, pyrazinamide and ethambutol followed by 4 months of isoniazid and rifampicin) for TPE treatment, the data regarding drug resistance among TPE patients are limited. The few studies examining the issue report a notable drug resistance. In suspected drug-resistant TPE, every effort is warranted to isolate M. tuberculosis to perform drug susceptibility testing and provide guided therapy. For this purpose, the use of cultures or molecular methods with pleural biopsies is superior to their use in pleural fluid. If still M. tuberculosis cannot be detected, prolonged administration of ethambutol with isoniazid and rifampicin during the continuation phase of treatment might be considered.

Antibiotic resistance, biochemical typing, and PFGE typing of Bifidobacterium strains commonly used in probiotic health foods.

This study firstly analyzed the antibiotic resistance, biochemical typing, and pulsed-field gel electrophoresis typing of 45 Bifidobacterium strains commonly used in health foods. Most strains were resistant to antibiotics but their antibiotic resistance rates were not high: Fos (56.52%), TET (43.48%), CRO (21.74%), AMC (15.22%), GEN (13.04%), RIF (10.87%), CHL (8.7%), CTX (6.52%), VAN (4.35%), and ERY (4.35%). The 45 strains could be divided into 14 pulsed-field gel electrophoresis types, of which the strain numbers of six pulsed-field gel electrophoresis types were more than one. All the Bifidobacterium strains could be divided into nine types by API50CHL biochemical identification. The same species displayed same biochemical typings, expect for B. animalis. Furthermore, the results confirmed that the same pulsed-field gel electrophoresis-type strains had closer antibiotic resistance patterns, and the same biochemical-type strain also had similar antibiotic resistance patterns.

Resistance patterns of Enterobacteriaceae in urines are similar in symptomatic and asymptomatic patients

Antibiograms of urine cultures are being used to guide empiric treatment for urinary tract infections (UTIs). However, roughly 50% of urine cultures are from patients with asymptomatic bacteriuria (ABU). It is unclear whether Enterobacteriaceae in ABU patients have similar resistance patterns as UTI patients. Hence, we aimed to compare the antimicrobial resistance patterns in patients with ABU to patients with symptomatic UTI. We found no major differences in resistance patterns, and therefore empiric treatment choices can be guided by antibiograms that include ABU patients.

Isolation and molecular characterization of group B Streptococcus from laboratory Long-Evans rats (Rattus norvegicus) with and without invasive group B streptococcal disease.

Purpose. Group B Streptococcus (S. agalactiae, GBS) is a Gram-positive opportunistic pathogen that inhabits the respiratory, urogenital and gastrointestinal tracts of humans and animals. Maternal colonization of GBS is a risk factor for a spectrum of clinical diseases in humans and a principle cause of neonatal meningitis and septicaemia.Methodology. We describe polymicrobial sepsis including GBS in two gravid adult female Long-Evans rats experiencing acute mortality from a colony of long-term breeding pairs. Fluorescent in situ hybridization confirmed GBS association with pathological changes in affected tissues, including the heart and uterus.Results. Characterization of seven GBS strains obtained from clinically affected and non-affected animals indicated similar antibiotic resistance and susceptibility patterns to that of human strains of GBS. The rat strains have virulence factors known to contribute to pathogenicity, and shared serotypes with human invasive isolates. Phylogenetic analyses revealed that one rat-derived GBS strain was more closely related to human-derived strains than other rat-derived strains, strengthening the notion that interspecies transmission is possible.Conclusions. To our knowledge, this is the first investigation of genotypic and phenotypic features of rat-derived GBS strains and their comparison to human- and other animal-derived GBS strains. Since GBS commonly colonizes commercially available rats, its exclusion as a potential pathogen for immunocompromised or stressed animals is recommended.

Antibiotic Resistance of Symbiotic Marine Bacteria Isolated from Marine Organisms in Jeju Island of South Korea

We investigated antibiotics resistance of bacteria isolated from marine organisms in Jeju Island of South Korea. We isolated 17 strains from a marine sponge, algaes, and sea water collected from Biyangdo on Jeju Island. Seventeen strains were analyzed by 16S rRNA gene sequencing for species identification and tested antibiotic susceptibility of strains against six antibiotics. Strain JJS3-4 isolated from S. siliquastrum showed 98% similarity to the 16S rRNA gene of Formosa spongicola A2T and was resistant to six antibiotics. Strains JJS1-1, JJS1-5, JJS2-3, identified as Pseudovibrio spp., and Stappia sp. JJS5-1, were susceptive to chloramphenicol and these four strains belonged to the order Rhodobacterales in the class Alphaproteobacteria. Halomonas anticariensis JJS2-1, JJS2-2 and JJS3-2 and Pseudomonas rhodesiae JJS4-1 and JJS4-2 showed similar resistance pattern against six antibiotics. We could isolate bacteria from marine organisms and their antibiotic resistance investigated, and conducted this study under the premise that such bacteria could produce secondary metabolites that could bring about useful antibiotic effects, resulting in species-specific results. We have a lot of unknown marine resources that we have not been able to explore yet. Bacteria are a valuable resource that can be developed into new useful materials.

First Case of Multiple Resistance to Glyphosate and PPO-inhibiting Herbicides in Rigid Ryegrass (Lolium rigidum) in Spain

Five rigid ryegrass populations suspected of being resistant to both glyphosate and oxyfluorfen were collected in southern Spain and tested under laboratory-controlled conditions. Four populations (Depuradora, Condado, AlamoRasilla, and Portichuelo) were treated with glyphosate for at least 15 consecutive years, and treatments during the last 5 yr were mixed with oxyfluorfen. The fifth population (4alamos) followed the same glyphosate treatment, although oxyfluorfen was never used to control it. Dose–response assays confirmed glyphosate resistance in all populations, with resistance indexes ranging from 11.7 to 37.5 (GR90). Shikimate accumulation assays consistently supported these data, as the most glyphosate-resistant populations (Depuradora and Condado) displayed the lowest shikimate levels. Surprisingly, four populations (Depuradora, Condado, AlamoRasilla, and Portichuelo) displayed 7.93- to 70.18-fold more resistance (GR90) to oxyfluorfen, despite limited selection pressure, showing a similar resistance pattern as that for glyphosate. The 4alamos population displayed oxyfluorfen GR90values that were similar to those observed in susceptible plants; however, this population was significantly more resistant in terms of plant survival (LD90). Protoporphyrin IX accumulation assays supported the results of dose–response assays, in that the most oxyfluorfen-resistant populations accumulated less protoporphyrin IX. Although more studies are needed, it seems that these five glyphosate-resistant weed populations display a natural tendency to easily develop resistance to oxyfluorfen, with the populations that have higher resistance to glyphosate also having higher resistance to oxyfluorfen.

Cellular conditions that modulate the fungicidal activity of occidiofungin.

To identify cellular conditions that significantly alter susceptibility of Saccharomyces cerevisiae, Candida albicans and Candida glabrata to the antimicrobial peptide, occidiofungin. Genetic and pharmacological approaches were used to determine a role for calcium signalling in occidiofungin sensitivity profiles for S. cerevisiae, C. albicans and C. glabrata strains of yeast. Minimum inhibitory concentration (MIC) and drop assays found that extracellular calcium resulted in a fourfold resistance, and this was independent of an intact calmodulin-calcineurin signalling pathway. A similar resistance was found in the presence of magnesium but not other cations. Occidiofungin was found to be ineffective against cells in a quiescent state when measured by MIC, drop assay and short-term time-kill assays. A similar resistance pattern was detected for S. cerevisiae cultures pre-exposed to cycloheximide or placed in depleted media conditions. Extracellular calcium results in fungal tolerance to occidiofungin bioactivity outside of the calmodulin-calcineurin pathway. In addition, the resistance of quiescent cells suggests that active cellular growth is a requirement for occidiofungin's mechanism of action. The identification of cellular conditions that have a role in the activity of occidiofungin provided insight into potential cellular targets of this novel antifungal.

Salmonella Weltevreden in integrated and non-integrated tilapia aquaculture systems in Guangdong, China

Integrated tilapia-pig farming, which uses manure from pigs as fertilizers in fish pond, is a traditional and common production system practised by small-scale farmers in South-east Asia. Although such systems may be environmentally sustainable, they also pose potential food safety hazards including transmission of faecal zoonotic pathogens and accumulation of antimicrobial and other chemical residues. This study aimed to determine differences in occurrence and characteristics of Salmonella spp. isolated from tilapia-pig and non-integrated aquaculture systems in Guangdong province, China. A total of 77 samples (9 pig feed, 19 fish feed, 9 pig faeces, 20 fish mucus and 20 fish intestine) from 10 tilapia-pig ponds and 10 non-integrated ponds were analysed. Salmonella spp. was found in fish mucus (20.0%), fish intestine (40.0%) and pig faeces (11.1%) from integrated ponds, and from fish mucus (40.0%) and fish intestine (40.0%) from non-integrated ponds. S. Weltevreden (76.5%) was by far the most common serovar showing limited antimicrobial resistance. One pig faeces sample contained S. Typhimurium whereas feed samples were found free of Salmonella spp.. DNA fingerprinting by the PFGE method showed a clonal relationship of S. Weltevreden which was supported by similar antimicrobial resistance patterns (sulfamethoxazole and trimethoprim resistance) as well as most isolates harbouring a 147-kb sized plasmid. The common finding of S. Weltevreden in both tilapia production systems indicates that this serovar may have a different ecology and increased survival in aquaculture environments in comparison with other Salmonella serovars. Further in vivo studies of the ecology of S. Weltevreden in aquaculture environments are needed.

Prevalence of high-level gentamicin-resistant Enterococcus faecalis in an Iranian hospital

This study was designed to determine the molecular characteristic and antimicrobial resistance of e nterococcal strains isolated from patients in an Iranian Hospital. Enterococcal strains were isolated from the burn patients. All strains were screened for genes encoding resistance to aminoglycoside [ aac(6 ' )-Ie-aph(2 '' )-Ia , aph (3') , ant (4' )], resistance to vancomycin ( vanA , vanB ), resistance to tetracycline ( tetK , tetL , tetM , tetO ), and resistance to erythromycin ( ermA , ermB , ermC ) by PCR and multiplex PCR–based methods. Genetic diversity was evaluated using Random Amplified Polymorphic DNA (RAPD)-PCR. All enterococcal isolates showed complete sensitivity to vancomycin with MIC ≤ 0.5µg/ml. Resistance to gentamicin, tetracycline, erythromycin, ciprofloxacin or quinopristin-dalfopristin was detected, whilst more than 96.2% of isolates were high-level gentamicin-resistant (HLGR) and multiresistant. The most prevalent aminoglycoside resistance gene was aac(6 ' )-Ie-aph(2 '' )-Ia, found in 96.2% (26/27) of the isolates. The most prevalent tetracycline resistance gene was tetM , found in 85.1% (23/27) of the isolates followed by tetL and tetO found in 7.4% (2/27) of the isolates. The ermA and ermB genes were detected in 33.3% (9/27) and 44.4% (12/27) of the isolates respectively. Random Amplified Polymorphic DNA (RAPD)-PCR analysis yielded 17 distinct profiles among 27 investigated isolates. One clusters of isolates shared the same RAPD patterns, while 16 isolates had unique RAPD patterns. we found that over the examined time period one RAPD genotype were common type and were disseminated among patients in the burn unit. Interestingly, most of these strains had an identical or very similar antibiotic and gene resistance pattern.

Comparison of methods for the identification and sub-typing of O157 and non-O157 Escherichia coli serotypes and their integration into a polyphasic taxonomy approach

AbstractPhenotypic, chemotaxonomic and genotypic data from 12 strains ofEscherichia coli werecollected, including carbon source utilisation profiles, ribotypes, sequencing data of the 16S–23S rRNA internal transcribed region (ITS) and Fourier transform-infrared (FT-IR) spectroscopic profiles. The objectives were to compare several identification systems forE. coliand to develop and test a polyphasic taxonomic approach using the four methodologies combined for the sub-typing of O157 and non-O157E. coli. The nucleotide sequences of the 16S–23S rRNA ITS regions were amplified by polymerase chain reaction (PCR), sequenced and compared with reference data available at the GenBank database using the Basic Local Alignment Search Tool (BLAST) . Additional information comprising the utilisation of carbon sources, riboprint profiles and FT-IR spectra was also collected. The capacity of the methods for the identification and typing ofE. colito species and subspecies levels was evaluated. Data were transformed and integrated to present polyphasic hierarchical clusters and relationships. The study reports the use of an integrated scheme comprising phenotypic, chemotaxonomic and genotypic information (carbon source profile, sequencing of the 16S–23S rRNA ITS, ribotyping and FT-IR spectroscopy) for a more precise characterisation and identification ofE. coli. The results showed that identification ofE. colistrains by each individual method was limited mainly by the extension and quality of reference databases. On the contrary, the polyphasic approach, whereby heterogeneous taxonomic data were combined and weighted, improved the identification results, gave more consistency to the final clustering and provided additional information on the taxonomic structure and phenotypic behaviour of strains, as shown by the close clustering of strains with similar stress resistance patterns.

Progenitor cells from atria, ventricle and peripheral blood of the same patients exhibit functional differences associated with cardiac repair

AimDeciding the best cell type for cardiac regeneration remains a big challenge. No studies have directly compared the functional efficacy of cardiac progenitor cells (CPCs) with extra-cardiac stem cells isolated from the same patient. Methods and resultsWe compared the functional characteristics of endothelial progenitor cells (EPCs), right atrial (RAA) CPCs and left ventricular (LV) CPCs isolated from the same patients (n=14). Within the same heart, RAA and LV CPCs exhibited marked differences in surface marker expression, with RAA CPCs exhibiting better expansion potential and migration properties. When subjected to hypoxia and serum starvation to simulate in vivo ischemic environment, RAA and LV CPCs exhibited similar pattern of resistance to apoptotic cell death under ischemia. Interestingly, EPCs exhibited highest resistance to apoptotic cell death, however, they also showed the lowest proliferation under hypoxia. RT-profiler array showed comparable gene expression pattern in RAA and LV CPCs, while they were differentially expressed in EPCs. Further, treating human umbilical vein endothelial cells with conditioned medium (CM) from LV showed maximum angiogenic potential, while cardiomyocytes treated with CM from RAA showed greatest survival under hypoxic conditions. ConclusionsResults from this study provide the first evidence that progenitor cells from different regions exhibit functional differences within the same patient.

Parallel narratives: resistance strategies of low-wage female hospitality workers and nineteenth-century black enslaved females

This research explores control and gendered resistance strategies of female low-level hospitality workers and nineteenth-century black enslaved females by linking resistance patterns in historically documented slave narratives with oral narratives of current female hospitality workers. Emerging narratives document parallel stories of oppression, abuse, devaluation, and exploitation and focus awareness on the subordinate position of low-level workers in an oppressor/oppressed relationship. Functioning under two different economic systems, slavery and capitalism, these low-level workers’ narratives allow similar patterns of resistance to surface and help us expand our understanding of worker exploitation, female resistance, and narrative as possessing liberatory potential.

Identification of a novel small-molecule compound targeting the influenza A virus polymerase PB1-PB2 interface

The PB1 C-terminal domain and PB2 N-terminal domain interaction of the influenza A polymerase, which modulates the assembly of PB1 and PB2 subunits, may serve as a valuable target for the development of novel anti-influenza therapeutics. In this study, we performed a systematic screening of a chemical library, followed by the antiviral evaluation of primary hits and their analogues. Eventually, a novel small-molecule compound PP7 that abrogated the PB1-PB2 association and impaired viral polymerase activity was identified. PP7 exhibited antiviral activities against influenza virus subtypes A (H1N1)pdm09, A(H7N9) and A(H9N2) in cell cultures and partially protected mice against lethal challenge of mouse-adapted influenza A (H1N1)pdm09 virus. Surprisingly, a panel of other subtypes of influenza virus, including A(H5N1) and A(H7N7), showed various degrees of resistance to the compound. Biochemical studies revealed a similar pattern of resistance on the impairment of polymerase activity. Molecular docking analyses suggested a PP7-binding site that appeared to be completely conserved among the subtypes of the virus mentioned above. Thus, we propose that alternative/additional binding site (s) may exist for the regulation of PB1-PB2 subunits assembly of influenza A virus.

Epidemiology of Antimicrobial Resistance in Escherichia coli Isolates from Raccoons (Procyon lotor) and the Environment on Swine Farms and Conservation Areas in Southern Ontario.

Antimicrobial resistance is a global threat to livestock, human and environmental health. Although resistant bacteria have been detected in wildlife, their role in the epidemiology of antimicrobial resistance is not clear. Our objective was to investigate demographic, temporal and climatic factors associated with carriage of antimicrobial resistant Escherichia coli in raccoons and the environment. We collected samples from raccoon paws and feces and from soil, manure pit and dumpsters on five swine farms and five conservation areas in Ontario, Canada once every five weeks from May to November, 2011–2013 and tested them for E. coli and susceptibility to 15 antimicrobials. Of samples testing positive for E. coli, resistance to ≥ 1 antimicrobials was detected in 7.4% (77/1044; 95% CI, 5.9–9.1) of raccoon fecal samples, 6.3% (23/365; 95% CI, 4.0–9.3) of paw samples, 9.6% (121/1260; 8.0–11.4) of soil samples, 57.4% (31/54; 95% CI, 43.2–70.8) of manure pit samples, and 13.8% (4/29; 95% CI, 3.9–31.7) of dumpster samples. Using univariable logistic regression, there was no significant difference in the occurrence of resistant E. coli in raccoon feces on conservation areas versus farms; however, E. coli isolates resistant to ≥ 1 antimicrobials were significantly less likely to be detected from raccoon paw samples on swine farms than conservation areas and significantly more likely to be detected in soil samples from swine farms than conservation areas. Resistant phenotypes and genotypes that were absent from the swine farm environment were detected in raccoons from conservation areas, suggesting that conservation areas and swine farms may have different exposures to resistant bacteria. However, the similar resistance patterns and genes in E. coli from raccoon fecal and environmental samples from the same location types suggest that resistant bacteria may be exchanged between raccoons and their environment.

The mosaic architecture of Aeromonas salmonicida subsp. salmonicida pAsa4 plasmid and its consequences on antibiotic resistance.

Aeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis in salmonids, is an issue especially because many isolates of this bacterium display antibiotic resistances, which limit treatments against the disease. Recent results suggested the possible existence of alternative forms of pAsa4, a large plasmid found in A. salmonicida subsp. salmonicida and bearing multiple antibiotic resistance genes. The present study reveals the existence of two newly detected pAsa4 variants, pAsa4b and pAsa4c. We present the extensive characterization of the genomic architecture, the mobile genetic elements and the antimicrobial resistance genes of these plasmids in addition to the reference pAsa4 from the strain A449. The analysis showed differences between the three architectures with consequences on the content of resistance genes. The genomic plasticity of the three pAsa4 variants could be partially explained by the action of mobile genetic elements like insertion sequences. Eight additional isolates from Canada and Europe that bore similar antibiotic resistance patterns as pAsa4-bearing strains were genotyped and specific pAsa4 variants could be attributed to phenotypic profiles. pAsa4 and pAsa4c were found in Europe, while pAsa4b was found in Canada. In accordance with their content in conjugative transfer genes, only pAsa4b and pAsa4c can be transferred by conjugation in Escherichia coli. The plasticity of pAsa4 variants related to the acquisition of antibiotic resistance indicates that these plasmids may pose a threat in terms of the dissemination of antimicrobial-resistant A. salmonicida subsp. salmonicida bacteria.

Bacterial diversity and antibiotic resistances of abundant aerobic culturable bacteria in input and output samples of 15 German biogas plants.

Determination of the diversities and antibiotic resistances of the most abundant aerobic culturable bacteria and their survival in 15 German biogas plants (BGPs). Microbiological standard media (complex and selective media) were applied to enumerate mesophilic and oligotrophic bacteria (Enterobacteriaceae, Salmonella, staphylococci and enterococci) in input and output samples of BGPs. Concentrations of aerobic culturable bacteria in outputs were mostly one to two orders of magnitude lower than in input samples. In total, 852 isolates from input and 902 from output samples were identified either by partial 16S rRNA gene sequencing or Matrix-assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) analysis. Antibiotic resistance screening of target families against veterinary relevant antibiotics resulted in similar resistance pattern in input and output samples. Potentially pathogenic bacteria were detected in output samples of BGPs, but in decreased abundance. The selectivity of the most applied clinical standard media was insufficient. Only little is known about the release of antibiotic resistant and potentially pathogenic bacteria from BGPs. However, this study indicates the detection of several potentially pathogenic bacteria in output samples, which showed several antibiotic resistances.

Multiple insecticide resistance in the major malaria vector Anopheles funestus in southern Ghana: implications for malaria control.

BackgroundUnderstanding the dynamics of insecticide resistance in African malaria vectors is crucial for successful implementation of resistance management strategies in the continent. This study reports a high and multiple insecticide resistance in Anopheles funestus from southern Ghana which could compromise the Malaria Operational Plan in this country, if not tackled. Adult Anopheles mosquitoes were collected in Obuasi and Adawukwa, in southern Ghana. Plasmodium infection rates, susceptibility to the main insecticides used in public health and the molecular basis of insecticide resistance were established.ResultsAn. funestus (sensu stricto) (s.s.) was the predominant mosquito species found resting inside the houses in Obuasi, while at Adawukwa it was found together with An. coluzzii. Parasite rates were high in An. funestus (s.s.) populations from both localities, with Plasmodium infection rates greater than 12.5 %. Both, An. funestus (s.s.) and An. coluzzii, from the two sites exhibited high resistance to the insecticide from various classes including the pyrethroids, carbamates and DDT, but remained fully susceptible to the organophosphates. A preliminary characterization of the underlying molecular mechanisms of resistance in An. funestus (s.s.) populations from both sites revealed that CYP6P9a, CYP6P9b, CYP6M7 and GSTe2 genes are upregulated, markedly higher in Obuasi (between 3.35 and 1.83 times) than in Adawukwa population. The frequency of L119F-GSTe2 and A296S-RDL resistance markers were also higher in Obuasi (42.5 and 68.95 % higher), compared with An. funestus (s.s.) populations from Adawukwa. These findings suggest that the similar resistance pattern observed in both An. funestus (s.s.) populations are driven by different mechanisms.ConclusionsResistance to multiple insecticides in public health use is present in malaria vectors from Ghana with major resistance genes already operating in the field. This should be taken into consideration in the design of resistance management strategies to avoid operational failure.

Epidemiology of Ureaplasma urealyticum and Mycoplasma hominis in the semen of male outpatients with reproductive disorders.

The aim of the present study was to investigate the association between Mycoplasma infection and infertility in male outpatients among a Chinese population. Epidemiological data, including prevalence, age distribution and antibiotic resistance profile of patients with an Ureaplasma urealyticum or Mycoplasma hominis infection were collected between 2009 and 2012. Among the 7,374 individuals analyzed, 3,225 patients (43.7%) were determined to be positive for infection with U. urealyticum, M. hominis or for both Mycoplasmas. Among the positive cultures, U. urealyticum was detected most frequently, while M. hominis was rarely found. The age range of 25-34 years was the preferred period for the positive detection. Tetracyclines and josamycin were the most effective agents against both genital Mycoplasmas, including in the case of co-infection. Macrolides (erythromycin, roxithromycin, azithromycin, clarithromycin except for josamycin) were effective against the majority of U. urealyticum clinical isolates, but were naturally resisted by M. hominis in this study. Fluoroquinolones had the lowest activity against U. urealyticum, particularly in cases of M. hominis co-infection. Furthermore, fluoroquinolones showed a similar pattern of drug resistance against M. hominis to that of U. urealyticum. Antibiotic resistance did not vary significantly over the test period. Notably, an elevated multi-drug resistance rate was observed in patients co-infected with both Mycoplasmas. In light of the epidemiological characteristics of genital Mycoplasmas in male infertility patients, the present results may aid Chinese clinicians to implement rational drug usage and avoid the overuse of antibiotics.

GES-11-producing Acinetobacter baumannii clinical isolates from Tunisian hospitals: Long-term dissemination of GES-type carbapenemases in North Africa

Acinetobacter baumannii is an emerging threat in healthcare facilities owing to its ability to be multidrug-resistant (MDR) and to be involved in outbreaks. GES-type extended-spectrum β-lactamases (ESBLs) have been increasingly identified in A. baumannii. In this study, clinical A. baumannii isolates were characterised using standard biochemical methods and antibiotic susceptibility testing. Antibiotic resistance genes were sought by PCR and sequencing. Genetic support was characterised using S1 nuclease pulsed-field gel electrophoresis (PFGE) mapping, conjugation and electroporation assays. The genetic environment was investigated by PCR, and genetic relatedness was investigated by PFGE. Two MDR A. baumannii clinical isolates susceptible only to colistin and rifampicin were isolated from a tracheal aspirate of a 49-year-old woman hospitalised in 2006 at the Military Hospital of Tunis, Tunisia, and from a tracheal aspirate of a 53-year-old man hospitalised in 2010 at the Institut Orthopédique Mohamed El Kassab of Tunis, Tunisia. PCR revealed that the two isolates harboured the acquired carbapenemase blaOXA-23 and ESBL blaGES-11 genes along with chromosomally-encoded blaOXA-51 and blaADC-like genes. PFGE revealed that these A. baumannii isolates were unrelated; nevertheless, plasmid analysis revealed a similar sized plasmid following electrophoresis of the isolates. In addition, A. baumannii CIP70.10 transformants displayed similar resistance patterns. blaGES-11 was integron-borne and the ISAbaI element was identified upstream of blaOXA-23 and blaADC-like. Here we described two unrelated clinical A. baumannii isolates producing GES-11 ESBL and OXA-23 carbapenemase from two Tunisian hospitals. This work further illustrates the emergence of GES-type β-lactamases in A. baumannii in North Africa as early as 2006.

A methicillin-resistant Staphylococcus aureus (MRSA) Sequence Type 8, spa type t11469 causing infection and colonizing horses in Italy.

A Methicillin-resistantStaphylococcus aureus(MRSA) was isolated in Italy from a pathological sample of a mare presenting chronic purulent sinusitis and that had undergone frontal-sinus surgery three months before. Humans, horses, dogs and environmental samples were subsequently collected at the mare's stable and at the Veterinary Hospital, where the mare was operated/hospitalized, and screened for the presence of MRSA that was detected from other horses and from the environment at both sites. All the MRSA isolates belonged to clonal complex (CC)8, ST8-t11469-SCCmec-IVa, and showed similar phenotypic and genetic multidrug resistance patterns and macrorestriction-pulsed-field gel electrophoresis profiles. The only MRSA detected from humans was a CC1, ST1-t127-SCCmec-IVa. This paper represents the first report of a clinical MRSA infection in a horse in Italy. This study also supports the opinion that improper use of antibiotics and hospitalization/surgery can represent risk factors for MRSA colonization/infection in horses, and that the environment is among important sources for exposure.