Objectives: To assess the value of screening for Clostridioides difficile colonization (CDC) at hospital admission in an endemic setting.Methods: A multi-centre study was conducted at four... Show moreObjectives: To assess the value of screening for Clostridioides difficile colonization (CDC) at hospital admission in an endemic setting.Methods: A multi-centre study was conducted at four hospitals located across the Netherlands. Newly admitted patients were screened for CDC. The risk of development of Clostridioides difficile infection (CDI) during admission and 1-year follow-up was assessed in patients with and without colonization. C. difficile isolates from patients with colonization were compared with isolates from incident CDI cases using core genome multi-locus sequence typing to determine whether onwards transmission had occurred.Results: CDC was present in 108 of 2211 admissions (4.9%), whereas colonization with a toxigenic strain (toxigenic Clostridoides difficile colonization [tCDC]) was present in 68 of 2211 admissions (3.1%). Among these 108 patients with colonization, diverse PCR ribotypes were found and no 'hypervirulent' PCR ribotype 027 (RT027) was detected (95% CI, 0-0.028). None of the patients with colonization developed CDI during admission (0/49; 95% CI, 0-0.073) or 1-year follow-up (0/38; 95% CI, 0-0.93). Core genome multi-locus sequence typing identified six clusters with genetically related isolates from patients with tCDC and CDI; however, in these clusters, only one possible transmission event from a patient with tCDC to a patient with CDI was identified based on epidemiological data.Conclusion: In this endemic setting with a low prevalence of 'hypervirulent' strains, screening for CDC at admission did not detect any patients with CDC who progressed to symptomatic CDI and detected only one possible transmission event from a patient with colonization to a patient with CDI. Thus, screening for CDC at admission is not useful in this setting. Monique J.T. Crobach, Clin Microbiol Infect 2023;29:891 & COPY; 2023 The Authors. Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/). Show less
Court, J.R. de la; Woudt, S.H.S.; Schoffelen, A.F.; Heijmans, J.; Jonge, N.A. de; Bruggen, T. van der; ... ; Schade, R.P. 2022
Objectives Among patients with haematological malignancy, bacteraemia is a common complication during chemotherapy-induced neutropenia. Resistance of gram-negative bacteria (GNB) to third... Show moreObjectives Among patients with haematological malignancy, bacteraemia is a common complication during chemotherapy-induced neutropenia. Resistance of gram-negative bacteria (GNB) to third-generation cephalosporins (3GC) is increasing. In order to explore the value of using surveillance cultures to guide empirical treatment e.g. choosing between carbapenem versus ceftazidime- we aimed to assess the distribution of pathogens causing bacteraemia in patients with haematological malignancy, and the proportion of 3GC-resistant GNB (3GC-R GNB) bacteraemia that was preceded by 3GC-R GNB colonization. Methods Using 11 years of data (2008-2018) from the Dutch national antimicrobial resistance surveillance system, we assessed the prevalence of 3GC-R GNB in episodes of bacteraemia, and the proportion of 3GC-R GNB bacteraemia that was preceded by 3GC-R GNB colonization. Colonization was defined as availability of any GNB surveillance isolate in the year before, independent of the causative micro-organism (time-paired isolates). Results We included 3887 patients, representing 4142 episodes of bacteraemia. GNB were identified in 715/4142 (17.3%), of which 221 (30.9%) were 3GC-R GNB. In 139 of these 221 patients a time-paired surveillance culture was available. In 76.2% (106/139) of patients these surveillance cultures already showed 3GC-R GNB isolates in the year prior to the culture date of the 3GC-R GNB positive blood isolate. Conclusions This multi-centre study shows that in patients with haematological malignancy, the majority of 3GC-R GNB bacteraemia is preceded by 3GC-R GNB colonization. Prospective clinical studies are needed to assess the safety and benefits of the use of surveillance-cultures to guide empirical therapy to restrict the empirical use of carbapenems in this population. Show less
Hoeven, A. van der; Bekker, V.; Jansen, S.J.; Saccoccia, B.; Berkhout, R.J.M.; Lopriore, E.; ... ; Beek, M.T. van der 2022
Background: The influence of the neonatal intensive care unit (NICU) design on the acquisition of multidrug-resistant organisms (MDROs) has not been well-documented.Aim: To examine the effect of... Show moreBackground: The influence of the neonatal intensive care unit (NICU) design on the acquisition of multidrug-resistant organisms (MDROs) has not been well-documented.Aim: To examine the effect of single room unit (SRU) versus open bay unit (OBU) design on the incidence of colonization with MDROs and third-generation cephalosporin-resistant bacteria (3G-CRB) in infants admitted to the NICU.Methods: Retrospective cohort study, including all infants admitted to the NICU of a tertiary care academic hospital two years prior to and two years following the transition from OBU to SRU in May 2017. Weekly cultures of throat and rectum were collected to screen for MDRO carriership. Incidence of colonization (percentage of all infants and incidence density per 1000 patient-days) with MDROs and 3G-CRB were compared between OBU and SRU periods.Findings: Incidence analysis of 1293 NICU infants, identified 3.2% MDRO carriers (2.5% OBU, 4.0% SRU, not significant), including 2.3% extended-spectrum b-lactamase-producing Enterobacterales carriers, and 18.6% 3G-CRB carriers (17% OBU, 20% SRU, not significant). No differences were found in MDRO incidence density per 1000 patient-days between infants admitted to OBU (1.56) compared to SRU infants (2.63).Conclusion: Transition in NICU design from open bay to SRUs was not associated with a reduction in colonization rates with MDROs or 3G-CRB in our hospital. Further research on preventing the acquisition and spread of resistant bacteria at high-risk departments such as the NICU, as well as optimal ward design, are needed. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of The Healthcare Infection Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Namibia was one of the final African states to gain independence, a political transformation which was the outcome of a decades-long liberation struggle. The global dimension of the struggle has... Show moreNamibia was one of the final African states to gain independence, a political transformation which was the outcome of a decades-long liberation struggle. The global dimension of the struggle has been duly recognised by generations of historians. As a result, archival materials related to this era - as well as the colonial ones preceding it – are to be found all over the world. Through a discussion of relevant archival collections pertaining to Namibian history - though located outside the boundaries of the Republic of Namibia – this article considers the global archival paper trail of Namibian colonisation and decolonisation. We shed light on the origins of various collections located in South Africa, Europe, North America, and beyond in order to reveal the ways in which the utilisation of such global archivalia can shape our understanding of Namibian decolonisation. This applies to government archives, private collections, institutional solidarity collections, as well as those of international organisations. We then delve into some of the promises and pitfalls of the digitisation of archival records, noting issues of ethics and methodology. Ultimately, we hold that historians must balance both internal and external Namibiana archivalia in crafting our arguments about the past, and we must balance both the merits and demerits of the digital turn in historical research. Show less
Terveer, E.M.; Fallon, M.; Kraakman, M.E.M.; Ormond, A.; Fitzpatrick, M.; Caljouw, M.A.A.; ... ; Fitzpatrick, F. 2019
This work attempts to understand Spanish colonial intercultural interactions in the early colonial period by compiling and analyzing data related to how these occurred at Concepción de la Vega,... Show moreThis work attempts to understand Spanish colonial intercultural interactions in the early colonial period by compiling and analyzing data related to how these occurred at Concepción de la Vega, one of the first settlements on the island of Hispaniola, in present-day Dominican Republic, using a Decolonial, Post-Processual, approach.The archaeological site associated to Concepción de la Vega, La Vega Vieja, was chosen as a study site because it was one of the earliest and most affluent Spanish settlements in the Americas. Research about the site offered the opportunity to assess some of the earliest Spanish, Amerindian and African entanglements and interactions in the Americas. Additionally, the site of La Vega Vieja has a tightly dated context (1495 to 1564) with no large, subsequent, occupation until the 20th century. The combination of both historical and archaeological data about Concepción de la Vega can help create a better understanding of the process through which the Spanish-American cultural tradition was created, and later disseminated, to the rest of Latin America.The research presented here focuses on the use of all artifacts (not just ceramics) as opposed to artifact manufacture chaine opératoire. It will focus particularly on use in nondomestic areas. This will be more in keeping with new trends in archaeological research, focusing more on problem solving, as opposed to a more chronological or typological approach. Show less
During the Holocene colonization of islands in the Pacific and Caribbean by agropastoral and horticulturalist communities, a variety of proxies (material, genetic, zoogeographic etc.) indicate... Show moreDuring the Holocene colonization of islands in the Pacific and Caribbean by agropastoral and horticulturalist communities, a variety of proxies (material, genetic, zoogeographic etc.) indicate substantial inter-island and inter-community contact. It has been suggested that this contact represents an adaptive response to mitigate intrinsic demographic fragility during the initial phases of island colonization, and that this exogamous imperative faded in the aftermath of initial dispersal as overall population density increased. Here, we evaluate this model by synthesizing and comparing increasingly available 87Sr/86Sr data from funerary populations in the Pacific and Caribbean. After performing basic hygienic discrimination, we conclude that the Caribbean data—both from across the region, and on an intra-site/island basis—lend support to this model, with high early in-migration succeeded by comparatively low in-migration in a relationship which, based on chi-square tests, is statistically significant (1, N = 290) = 4.046, p = 0.044). The Pacific situation is more complex, with data from the Bismarck Archipelago and northern Solomon Islands skewing the analysis. However, in considering these data in detail, we demonstrate that there are reasons to suppose that the Pacific data may also tentatively support a model of high rates of in-migration being replaced later in settlement histories by comparatively low rates. We conclude by highlighting future directions for this incipient research program. Show less
Potato blackleg caused by pectinolytic Pectobacterium and Dickeya species is a bacterial disease creating serious economic losses in (seed)potato production worldwide. Effective management to... Show morePotato blackleg caused by pectinolytic Pectobacterium and Dickeya species is a bacterial disease creating serious economic losses in (seed)potato production worldwide. Effective management to control blackleg is absent and validated, cost-effective detection protocols for blackleg bacteria do not exist. This situation results partially from the lack of knowledge of the ecology of blackleg pathogens in general, and Dickeya spp. in particular. Since 2000 an increasing frequency of Dickeya spp. in seed potatoes in Europe has been observed which is connected to emergence of a new species belonging to biovar 3 but unclassified inside known and described six Dickeya species. This species was provisionally named __D. solani__ and isolated from potato in The Netherlands, Finland, Poland, Germany, Belgium, France, United Kingdom and Israel. The objectives of the study described in this thesis were to acquire knowledge on the ecology (i. e. distribution of Dickeya spp. in seed potato tubers, role of the soil-borne inoculum in disease incidence, role of the aerial haulm infection for the blackleg incidence in progeny tubers) of a new genetic clade of biovar 3 Dickeya spp.; and to find and characterize in detail the valuable biocontrol agent(s) (isolated from rotten potato tissue) to cure seed potato tubers from blackleg caused by biovar 3 Dickeya spp. (__D. solani__). Direct isolation of viable bacterial cells using (selective) plating techniques combined with molecular (16S rDNA and Rep-PCR), serological (DAS-ELISA) and biochemical (biovar determination) characterization of the isolates were used to evaluate the presence of Dickeya and Pectobacterium spp. in different plant parts and tissues. Bacterial population dynamics in planta was studied in greenhouse experiments. For the studies on colonization of potato tissues by biovar 3 Dickeya spp. (__D. solani__) and Serratia plymuthica A30, bacterial strains were transformed with plasmid-based genes coding for red or green fluorescent proteins (DsRed and GFP, respectively) that were constitutively expressed in bacterial cells. Epifluorescence stereo microscopy and confocal laser scanning microscopy were used to visualize bacterial presence in different tissues of potato tubers and plants. Studies on the distribution of Dickeya ( and __D. solani__) and Pectobacterium species in seed potatoes revealed that the pathogens were distributed unevenly inside tubers and that the stolon end tuber part harbored the highest bacterial inoculum, whereas deeper located tissues were usually not colonized. Studies on the importance of soil-borne biovar 3 Dickeya sp. (__D. solani__) inoculum for systemic colonization of potato plants and latent infection of progeny tubers unveiled that D. solani is able to systemically colonize progeny tubers from soil via the roots and to cause true blackleg symptoms in infected plants after soil infestation. Studies on the role of haulm infections for latent contamination of progeny tubers by D. solani presented that the injection of bacteria into stems can result in the downward vascular translocation and a colonization of underground plant parts and finally, latent contamination of progeny tubers. Potato leaves inoculation with a biovar 3 Dickeya sp., showed degradation of the inoculated plant material and spreading of the internal inoculum to the petiole and axil and finally to the main stem but bacteria were not detected in the underground plant parts. Studies on characterization of the bacteria antagonistic to biovar 3 Dickeya sp. (__D. solani__) allowed to obtain knowledge of the presence of such strains in rotten potato tissue and on possibility of their used in the biocontrol of Dickeya spp. in potato. Selection of a candidate strain (Serratia plymuthica A30) that was effective in protecting potato plant tissue from blackleg was performed on the basis of in vitro and greenhouse tests. In vitro tests proved that S. plymuthica A30 possess different mechanisms by which it can control Dickeya spp. (i. e. production of antibiotics and biosurfactants). The interaction of D. solani and S. plymuthica A30 under greenhouse conditions was investigated in detail using artificially co-inoculated tubers and by application of A30 to the soil. It was showed that both micro-organisms interact in situ and that S. plymuthica A30 is able to decrease or eradicate Dickeya sp. inoculum from infected potato plants by competition un the same niches. In conclusion, a new biovar 3 Dickeya spp. strain was present in high densities in stolon end of naturally infected progeny tubers. The bacterium efficiently colonized various plant tissues after artificial inoculation of soil or haulms and was able to systemically colonize entire potato plant in relatively short time. For biocontrol of biovar 3 Dickeya spp. in potato, a bacterial strain characterized as S. plymuthica A30 tested in in vitro and under greenhouse conditions proved to have great potential for controlling blackleg in conditions favorable for disease development and when Dickeya sp. was applied in the high inoculum. The A30 strain effectively protected potato plants against blackleg in greenhouse experiments, both in vacuum infiltrated tuber and when applied as superficial treatment during planting. Treatment with A30 reduced the disease incidence to 0%. S. plymuthica A30 was able to colonize the plants internally, and combat internal infections with D. solani. Show less
