Alessandro Bartoloni

Rapid Dissemination and Diversity of CTX-M Extended-Spectrum β-Lactamase Genes in Commensal Escherichia coli Isolates from Healthy Children from Low-Resource Settings in Latin America

ABSTRACT A survey carried out in 2005 among members of a healthy population of children living in Bolivia and Peru revealed that fecal carriage of Escherichia coli strains resistant to expanded-spectrum cephalosporins was remarkably increased compared to that observed in the same settings in 2002 (1.7% in 2005 versus 0.1% in 2002). In this work, we demonstrated that this phenomenon was mainly related to the dissemination of CTX-M-type extended-spectrum β-lactamase (ESBL) determinants among commensal E. coli strains. Of 50 ESBL-producing isolates collected in the 2005 survey, 44 harbored a CTX-M-type and 6 an SHV-type (SHV-2 or SHV-12) ESBL. Compared to 2002 results, an increased diversity of CTX-M-type ESBLs was also observed: members of the CTX-M-1 group (CTX-M-15) emerged in Bolivia (where only CTX-M-2 was observed in 2002), while members of the CTX-M-9 group (CTX-M-14 and CTX-M-24) emerged in Peru (where only CTX-M-15 and CTX-M-2 were observed in 2002). A new CTX-M-2 variant named CTX-M-56 was also detected. Molecular characterization of the CTX-M-producing isolates and gene transfer experiments suggested that different mechanisms could be involved in the spreading of different CTX-M group determinants and revealed that additional resistance determinants for non-β-lactam antibiotics were preferentially carried by plasmids encoding certain CTX-M variants (CTX-M-15 and variants of the CTX-M-2 group). Three CTX-M-15-encoding conjugative plasmids from Peruvian isolates carried the new fluoroquinolone resistance gene aac(6′)-Ib-cr. To our best knowledge, this is the first report of the detection of aac(6′)-Ib-cr in Latin America.

An autochthonous case of Zika due to possible sexual transmission, Florence, Italy, 2014.

We report a case of Zika virus infection imported in Florence, Italy ex-Thailand, leading to a secondary autochthonous case, probably through sexual transmission. The two cases occurred in May 2014 but were retrospectively diagnosed in 2016 on the basis of serological tests (plaque reduction neutralisation) performed on stored serum samples. Our report provides further evidence that sexual transmission of Zika virus is possible.

Zika virus infections imported to Italy: Clinical, immunological and virological findings, and public health implications

We report the first two cases of laboratory confirmed Zika virus (ZIKV) infections imported into Italy from French Polynesia. Both patients presented with low grade fever, malaise, conjunctivitis, myalgia, arthralgia, ankle oedema, and axillary and inguinal lymphadenopathy. One patient showed leukopenia with relative monocytosis and thrombocytopenia. The diagnosis was based on ZIKV seroconversion in both cases and on ZIKV RNA detection in one patient from acute serum sample. Sera from both patients exhibited cross-reactivity with dengue virus antigens. Our immunological analysis demonstrated that recovery from ZIKV infection is associated with restoration of normal numbers of immune cells in the periphery as well as with normal function of antigen-presenting cells. ZIKV is an emerging arbovirus, which has recently spread extensively in tourist destinations on several West Pacific islands. Returning viremic travelers may ignite autochthonous infections in countries like Italy, which are infested by Aedes albopictus, a suitable vector for ZIKV. The role of clinicians is crucial and includes early diagnosis and timely notification of public health authorities in order to quickly implement adequate focal vector control measurements.

Emergence in Italy of Klebsiella pneumoniae Sequence Type 258 Producing KPC-3 Carbapenemase

KPC-type carbapenemases are emerging resistance determinants in Klebsiella pneumoniae and other gram-negative pathogens, being an increasingly important mechanism of acquired resistance to carbapenems and other β-lactams ([9][1], [10][2]). KPC producers have recently undergone an important

Prevalence of epilepsy in rural Bolivia A door-to-door survey

Objective: To carry out a door-to-door survey in rural areas of the Cordillera Province, Santa Cruz Department, Bolivia, to determine the prevalence of neurologic diseases (epilepsy, stroke, parkinsonism, and peripheral neuropathy) in a sample of approximately 10,000 inhabitants. Methods: A team of nondoctor health workers administered a standard screening instrument for neurologic diseases—a slightly modified version of the World Health Organization protocol. All subjects found positive during the screening underwent a neurologic examination. Results: On screening, the authors found 1,130 positive subjects, of whom 1,027 were then investigated by neurologists. On the basis of the definition proposed by the International League Against Epilepsy, we detected 124 epileptic patients (prevalence, 12.3/1,000), 112 of whom had active epilepsy (prevalence, 11.1/1,000) on the prevalence day (November 1, 1994). Peak age-specific prevalence occurred in the 15 to 24-year age group (20.4/1,000). Sex-specific prevalence was higher in women (13.1/1,000) than men (11.4/1,000). Eighty-nine patients (71.8%) underwent a standard EEG recording. Considering both EEG and clinical data, partial seizures were the most common type (53.2%) based on the classification of the International League Against Epilepsy. The mean age at onset was 20.7 years for partial seizures and 13.6 years for generalized seizures. Only 10.5% of patients had received specific treatment for more than 2 months of their life. Conclusion: This report on epilepsy prevalence in Bolivia confirms that epilepsy is a major health problem in rural areas of developing countries.

Zika virus infection in a traveller returning to Europe from Brazil, March 2015.

We report a case of laboratory-confirmed Zika virus infection imported into Europe from the Americas. The patient developed fever, rash, and oedema of hands and feet after returning to Italy from Brazil in late March 2015. The case highlights that, together with chikungunya virus and dengue virus, three major arboviruses are now co-circulating in Brazil. These arboviruses represent a burden for the healthcare systems in Brazil and other countries where competent mosquito vectors are present.

Epilepsy, cysticercosis, and toxocariasis: a population-based case-control study in rural Bolivia.

Objective To assess the relationship between epilepsy and infection with Taenia solium and Toxocara canis with a case-control study, in the rural area of the Cordillera Province, Bolivia. Methods A preliminary two-phase door-to-door prevalence survey determined the prevalence of epilepsy and identified cases and control subjects. At least two control subjects per case were selected, matching on sex, age, and community of residence. Cases and control subjects were assessed serologically for antibodies against T. canis by ELISA and against T. solium by enzyme-linked immunoelectrotransfer blot (EITB). Results The prevalence survey found 130 confirmed cases of epilepsy, of which 113 were eligible for the case-control study (59 partial seizures and 54 generalized seizures). Two hundred thirty-three control subjects were selected. Multivariable analysis for a matched case-control study was carried out. There was an association between EITB positivity for T. solium and epilepsy with an OR of 1.85 (95% CI 0.99 to 3.4) for all cases. A stronger association was found in those with partial epilepsy with a late onset of disease (15 years and older), where the OR was 3.66 (95% CI 1.10 to 12.10). A positive association was also found with T. canis for all cases with an OR of 2.70 (95% CI 1.41 to 5.19). This increased for those with late-onset partial epilepsy to an OR of 18.22 (95% CI 2.10 to 158.10). Conclusion This finding suggests that both neurocysticercosis and toxocariasis may in part explain the higher prevalence of epilepsy, particularly partial epilepsy, in developing countries.

Multidrug-resistant commensal Escherichia coli in children, Peru and Bolivia.

Healthy children in urban areas have a high prevalence of fecal carriage of drug-resistant E. coli.

Population Structure and Resistance Genes in Antibiotic-Resistant Bacteria from a Remote Community with Minimal Antibiotic Exposure

ABSTRACT In a previous study, we detected unexpectedly high levels of acquired antibiotic resistance in commensal Escherichia coli isolates from a remote Guaraní Indian (Bolivia) community with very low levels of antibiotic exposure and limited exchanges with the exterior. Here we analyzed the structure of the resistant E. coli population from that community and the resistance mechanisms. The E. coli population (113 isolates from 72 inhabitants) showed a high degree of genetic heterogeneity, as evidenced by phylogenetic grouping (77% group A, 10% group B1, 8% group D, 5% group B2) and genotyping by randomly amplified polymorphic DNA (RAPD) analysis (44 different RAPD types). The acquired resistance genes were always of the same types as those found in antibiotic-exposed settings [blaTEM, blaPSE-1, catI, cmlA6, tet(A), tet(B), dfrA1, dfrA7, dfrA8, dfrA17, sul1, sul2, aphA1, aadA1, aadA2, aadA5, aadB, and sat-1]. Class 1 and class 2 integrons were found in 12% and 4% of the isolates, respectively, and harbored arrays of gene cassettes similar to those already described. The cotransferability of multiple-resistance traits was observed from selected isolates and was found to be associated with resistance conjugative plasmids of the F, P, and N types. Overall, these data suggest that the resistance observed in this remote community is likely the consequence of the dissemination of resistant bacteria and resistance genes from antibiotic-exposed settings (rather than of an independent in situ selection) which involved both the clonal expansion of resistant strains and the horizontal transfer/recombination of mobile genetic elements harboring resistance genes.

High Prevalence of Acquired Antimicrobial Resistance Unrelated to Heavy Antimicrobial Consumption

In a very remote rural Bolivian community where the use of antimicrobials has been minimal and where exchanges with the exterior are very limited, 67% of subjects were found to be carriers of fecal Escherichia coli with acquired resistance to >/=1 antimicrobial agent(s); the highest rates were observed for tetracycline (64%), ampicillin (58%), trimethoprim-sulfamethoxazole (50%), and chloramphenicol (41%). The most relevant implication of these findings is that, in certain settings, the spread and maintenance of antimicrobial resistance can occur, regardless of whether selective pressure generated by the use of antimicrobials is present.