Description of novel resistance islands harbouring blaCTX-M-2 in IncC type 2 plasmids.

OBJECTIVES: We sequenced two IncA/C plasmids harbouring blaCTX-M-2 in Klebsiella pneumoniae clinical isolates and compared their antibiotic resistance islands. METHODS: Transconjugants were obtained from two clinical K. pneumoniae isolates harbouring blaCTX-M-2. Plasmid DNA from transconjugants underwent short-read whole-genome sequencing, reads were assembled, and gaps were closed by PCR and sequencing. Determination of plasmid replicons, antibiotic resistance genes, identification and characterisation of insertion sequence (IS) elements, and comparison with publicly available plasmid sequences were performed. RESULTS: blaCTX-M-2 was located in a complex class 1 integron In35::ISCR1::blaCTX-M-2, inserted in two different transposons designated Tn7057 and Tn7058, that reside in the resistance islands of plasmids pUR-KP0923 and pUR-KP1025, respectively. The general modules of both transposons were In35::ISCR1::blaCTX-M-2-Tn1000-like-Tn2*-ISKpn11-12-13 variable module-ΔTn21. In Tn7057 there was ΔIS10R-catA2 associated with an additional ISKpn13. Both plasmids belonged to IncC type 2 and ST3. pUR-KP0923 was 167 138 bp in length and had a 37 926-bp resistance island at position 4 (RI-4). Plasmid pUR-KP1025 was 168 128 bp with a RI-4 of 36 222 bp. CONCLUSION: This report describes the molecular nature of two transposons (Tn7057 and Tn7058) harbouring blaCTX-M-2 that reside in IncC type 2 ST3 plasmids. These transposons mediate resistance to oxyimino-cephalosporins, gentamicin and, in the case of Tn7057, chloramphenicol. CTX-M-2 is an important extended-spectrum ß-lactamase (ESBL) to South American epidemiology. It is remarkable that despite being only two plasmid sequences, the information revealed here could contribute to a better understanding of the resistance islands from IncC type 2 plasmids.

Prevalence and molecular characterisation of carbapenemase-producing Enterobacterales in an outbreak-free setting in a single hospital in Uruguay.

OBJECTIVES: This study aimed to characterise all carbapenemase-producing enterobacteria (CPE) isolates obtained from an outbreak-free setting in Uruguay. METHODS: We studied 12 CPE isolated from Hospital de Clínicas between 2012-2016. Bacterial identification and antibiotic susceptibility testing were performed using VITEK®2 and Sensititre or agar dilution, respectively. Antimicrobial resistance genes and mobile genetic elements were identified by PCR and sequencing. Multilocus sequence typing was performed for Klebsiella pneumoniae. Plasmid conjugation was assessed, plasmid size was estimated by S1-PFGE and plasmid incompatibility groups were sought by PCR. RESULTS: Among 8364 enterobacteria, 12 CPE were isolated from urine, blood culture, wound, peritoneal fluid and punch samples. NDM-1 was the most prevalent carbapenemase, followed by VIM-2 and KPC-2. All isolates were resistant to gentamicin, cefotaxime, ceftazidime, trimethoprim/sulfamethoxazole, ciprofloxacin and imipenem and were susceptible to fosfomycin. We characterised six class 1 integrons: dfrA12-orfF-aadA2; aacA4-blaOXA-2-orfD; aadB-aadA2; dfrA1; aadB-blaOXA-10-aadA1; and blaVIM-2-dfrA7. An association between various aminoglycoside, ß-lactam and fluoroquinolone resistance genes were observed, some of them located in transferable plasmids belonging to incompatibility groups IncC, IncHI1 and IncM1. We described a new composite transposon (assigned Tn6935) including blaNDM-1 flanked by two directly-oriented copies of a Tn3-like element ISKox2-like family transposase. The sequence types of K. pneumoniae isolates were ST11, ST14 and ST661. CONCLUSIONS: The presence of CPE is sporadic and could be due to measures taken by the Public Health Committee. Nevertheless, the coexistence of several resistance mechanisms and their presence in conjugative plasmids and high-risk clones is worrisome.

Allodemic distribution of plasmids co-harbouring blaCTX-M-15/aac(6')-Ib-cr/qnrB in Klebsiella pneumoniae is the main source of extended-spectrum ß-lactamases in Uruguay's paediatric hospital.

OBJECTIVES: This study aimed to describe the characteristics of clinical isolates of extended-spectrum ß-lactamase (ESBL)-producing enterobacteria (EPE) in Uruguay's paediatric hospital. METHODS: ESBLs, qnr alleles and aac(6')-Ib-cr were sought and characterised in EPE isolated between March 2010 and March 2012. Transfer of resistance determinants was assessed by conjugation. Incompatibility (Inc) groups, plasmid toxin-antitoxin systems (TAS) and plasmid size were determined in transconjugants. Clonality was analysed by pulsed-field gel electrophoresis. Multilocus sequence typing was done for ESBL-producing Klebsiella pneumoniae. RESULTS: A total of 77 EPE isolates were characterised, comprising 43% K. pneumoniae, 19.5% Serratia marcescens, 19.5% Escherichia coli, 17% Enterobacter cloacae and 1% Klebsiella oxytoca. ESBLs belonged mainly to the blaCTX-M family (69.6%) [blaCTX-M-15 (45%) and blaCTX-M-2 (31%)]. The aac(6')-Ib-cr/qnrB duplex was the most frequently detected plasmid-mediated quinolone resistance mechanism; this association was detected in K. pneumoniae harbouring blaCTX-M-15. Transconjugants were obtained for 71% of the EPE. Amongst transconjugants, certain combinations were found between ESBLs and Inc group, e.g. IncA/C-blaCTX-M-2, IncHI1/HI2-blaCTX-M-9 and IncHI1/HI2-blaSHV-12. In addition, the combination ccdAB-blaCTX-M-15 was also found. K. pneumoniae isolates harbouring blaCTX-M-15/aac(6')-Ib-cr/qnrB showed allodemic behaviour, with a predominance of ST14, ST45 and ST48. CONCLUSIONS: In this study, epidemiological changes in ESBL distribution could be explained by the spread of K. pneumoniae harbouring blaCTX-M-15/aac(6')-Ib-cr/qnrB, encoded mainly on conjugative plasmids featuring ccdAB TAS. Since reports of TAS in K. pneumoniae plasmids are scarce, new strategies are needed to combat intrinsic selection pressure exerted by the association, in conjugative plasmids, of resistance mechanisms with TAS.

Emergence of KPC-producing Klebsiella pneumoniae in Uruguay: infection control and molecular characterization.

We describe the first outbreak of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP), the infection control measures adopted and the shift in resistance patterns of isolates during antibiotic treatment. The ST258 KPC-KP strain exhibited a multiresistant antibiotic phenotype including co-resistance to gentamycin, colistin and tigecycline intermediate susceptibility. Isolates before and after treatment had different behaviour concerning their antibiotic susceptibility and the population analysis profile study. A progressive increase in the aminoglycosides (acquiring amicacin resistance) and ß-lactam MICs, and a decreased susceptibility to fosfomycin was observed throughout the administration of combined antimicrobial regimens including meropenem. A high meropenem resistance KPC-KP homogeneous population (MIC 256 Jg/mL), could arise from the meropenem heterogeneous low-level resistance KPC-KP population (MIC 8 Jg/mL), by the selective pressure of the prolonged meropenem therapy. The kpc gene was inserted in a Tn4401 isoform a, and no transconjugants were detected. The core measures adopted were successful to prevent evolution towards resistance dissemination.

First report of the ceftazidimase CTX-M-19 in South America.

We report the first detection of bla CTX-M-19 in South America, harboured in an Escherichia coli isolate obtained from a urine sample; such an isolate belonged to phylogenetic group A, ST603, and showed a ceftazidimase profile. bla CTX-M-19 was encoded in an approximately 100 kb IncI1/IncF conjugative plasmid, featuring pndAC and hok/sok addiction systems; the ß-lactamase gene was flanked upstream by three tandem-like transposons (IS26, IS10 and ISEcp1), inserted one inside the other, and downstream by IS903.

Prevalence of Salmonella enterica in poultry and eggs in Uruguay during an epidemic due to Salmonella enterica serovar Enteritidis.

Salmonella enterica serovar Enteritidis (S. Enteritidis) is frequently associated with food-borne disease worldwide. Poultry-derived products are a major source. An epidemic of human infection with S. Enteritidis occurred in Uruguay, and to evaluate the extent of poultry contamination, we conducted a nationwide survey over 2 years that included the analysis of sera from 5,751 birds and 12,400 eggs. Serological evidence of infection with Salmonella group O:9 was found in 24.4% of the birds. All positive sera were retested with a gm flagellum-based enzyme-linked immunosorbent assay, and based on these results, the national prevalence of S. Enteritidis infection was estimated to be 6.3%. Salmonellae were recovered from 58 of 620 pools made up of 20 eggs each, demonstrating a prevalence of at least 1 in every 214 eggs. Surprisingly, the majority of the isolates were not S. Enteritidis. Thirty-nine isolates were typed as S. Derby, 9 as S. Gallinarum, 8 as S. Enteritidis, and 2 as S. Panama. Despite the highest prevalence in eggs, S. Derby was not isolated from humans in the period of analysis, suggesting a low capacity to infect humans. Microarray-based comparative genomic hybridization analysis of S. Derby and S. Enteritidis revealed more than 350 genetic differences. S. Derby lacked pathogenicity islands 13 and 14, the fimbrial lpf operon, and other regions encoding metabolic functions. Several of these regions are present not only in serovar Enteritidis but also in all sequenced strains of S. Typhimurium, suggesting that these regions might be related to the capacity of Salmonella to cause food-borne disease.

[Genetic environment of CTX-M-2 in Klebsiella pneumoniae isolates from hospitalized patients in Uruguay]. / Entorno genético de CTX-M-2 en aislamientos de Klebsiella pneumoniae provenientes de pacientes hospitalizados en Uruguay.

We studied two CTX-M-2-producing Klebsiella pneumoniae clinical strains, K96005 and K13, isolated from hospitalized patients in Uruguay, during 1996 and 2003, respectively. The genomic surroundings of bla(CTX-M-2) were characterized by PCR-mapping and DNA sequencing. Our results show that blaCTX-M-2 is included in a complex class-1 integron (InK13), associated with an orf513 in both isolates. The genetic array of the integron, aac(6')-lb, bla(OxA,2), orfD (gene cassette region), associated with an orf513-bla(CTX-M-2), seems to be widely disseminated over the Rio de la Plata region.

Association of broad-spectrum antibiotic use with faecal carriage of oxyiminocephalosporin-resistant enterobacteriaceae in an intensive care unit.

The link between administration of antibiotics and detection of third-generation-cephalosporin-resistant (TGCR) enterobacteriaceae in faeces was studied in patients in a burns intensive care unit (ICU). The presence of extended-spectrum beta-lactamase producers was also determined in these isolates. At least two rectal swab samples were taken from 43 of 72 patients admitted to the ICU from January 1998 to June 1999. Antibiotic resistance tests were performed for all isolated enterobacteriaceae using the methods of the National Committee for Clinical Laboratory Standards. Only 10 out of 30 antibiotic-treated patients showed TGCR enterobacteriaceae in faeces. Fisher's exact test showed a relationship between the administration of oxyiminocephalosporins (third-generation cephalosporins) (P=0.002) or carbapenems (P=0.003) and the isolation of TGCR enterobacteriaceae from faeces. The administration of oxyiminocephalosporins led to the selection of resistant strains in the faecal flora.

Efecto del Lactobacillus casei administrado en el suero de rehidratación oral, en el tratamiento de la enfermedad diarreica aguda / Efficacy of Lactobacillus GG in oral rehidratation solution

El probiótico Lactobacillus GG es efectivo en promover una recuperación rápida de la diarrea aguda infantil producida por rotavirus. Hay poca información, sobre el rol de este agente en el efecto sobre la diarrea producida por otros gérmenes, tampoco hay evidencia de su eficacia administrada en la sal de hidratación oral para pscientes con diarrea de diversas causa. Método: Niños de 1 mes a 3 años de edad con enfermedad diarreica aguda fueron enrolados en una investigación doble ciego. Pacientes fueron randomizados y colocados en al grupo A recibiendo sal de hidratación y placebo, y en el grupo recibiendo, el mismo con el agragado de una preparación viva de Lactobacuillus GG. Luego de la hidratación en las 4 ó 6 horas se les ofreció su dieta habitual. Resultados: enrolamos 97 pacientes 52 del grupo A y 45 del grupo B. Duración de la diarrea luego del enrolamiento fue 7 días para el grupo A y 4 días para el grupo B (p<0.005).Para los niños rotavirus positivos la diarrea duró 6 días para el grupo A y 3 días para el grupo B (p<0.005).La diarrea duró más de 10 días, 5 para el grupo A y 1 para el grupo B. Conclusión: Administrar sal de hidratación oral conteniendo Lactobacillus GG a niños con enfermedad diarreica aguda es segura y resulta en duración menor de esta y tiene menos chance de pasar a curso prolongado. (AU)

Gemcitabine, ifosfamide, cisplatin (GIP) for the treatment of advanced non-small cell lung cancer: a phase II study of the italian oncology group for clinical research (GOIRC).

The purpose of this study was to evaluate the activity and the toxicity of the combination of gemcitabine with ifosfamide and cisplatin (GIP) in chemonaive patients with advanced non small cell lung cancer (NSCLC). Eighty chemonaive patients with Stage IIIB-IV NSCLC were treated with the combination of gemcitabine 1 g/m(2) on Days 1 and 8, ifosfamide 2 g/m(2) on Day 1 and cisplatin 80 mg/m(2) on Day 2. Cycles were administered on an outpatient basis every 3 weeks. Hematologic toxicity was the main side effect; Grade III-IV thrombocytopenia was observed in 54 (67%) patients and Grade III-IV leucopenia in 44 (55%) patients, with 4 episodes of febrile neutropenia and 1 toxic death. Thirteen patients received platelet transfusions and 38 were transfused with packed red cells. All patients were evaluable for response. The overall response rate was 54% (95% confidence interval 43 to 65%) with 1 complete response. In patients with Stage IIIB and IV disease, response rates were 58% and 52%, respectively. Median time to progression was 40 weeks (range 0-114) and median overall survival was 12 months (16.6 months for stage IIIB and 10.4 months for stage IV). Median and minimum follow-up were 19 and 12 months, respectively. The GIP combination shows a response rate and overall survival of clinical interest. Hematologic toxicity was the main toxic effect, especially in patients with low performance status. This regimen will be tested in a Phase III randomized trial.

Chronic neutrophilic leukemia: description of a new case with karyotypic abnormalities.

A further case of chronic neutrophilic leukemia (CNL) is reported. On karyotype analysis of the bone marrow aspirate, all of the examined cells showed trisomy of chromosome 9 and partial deletion of the long arms of chromosome 20. This anomaly has never before been reported in CNL, and it could be directly associated to the disease.

[Value of some biological variables for the diagnosis of alcoholism in a hospital population]. / Valore di alcune variabili biologiche per la diagnosi di alcoolismo in una popolazione ospedaliera.

279 male patients consecutively admitted to a medical ward were interviewed about their drinking habits using a CAGE-like questionnaire and were subdivided into teetotallers, normal-, borderline-, heavy-drinkers. The mean values of the following laboratory tests resulted significantly different in heavy drinkers compared with the others: mean cell volume, gamma-glutamyl-transpeptidase, serum urea (BUN), SGOT, SGPT, total bilirubin. No significant difference was found for triglycerides, uric acid, albumin and gamma-globulins. Sensitivity, specificity, predictive values of positive test and negative test, "goodness" were calculated for each of the 6 above-mentioned tests. Each of them had a linear correlation (inverse for BUN, direct for the others) between amount of alcohol intake and level of the test.