Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae in healthy Swedish preschool children.

AIM: The objective was to determine the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in faeces from healthy Swedish preschool children and to establish whether transmission took place between children in preschools. METHODS: Diapers from children attending preschools in Uppsala city were collected during September to October 2010, and the faeces was cultured. Antibiotic profiles and carriage of CTX-M, TEM, SHV and AmpC type enzymes were determined. PCR-positive isolates were further characterized by sequencing and epidemiological typing. Statistics on antibiotic use and ESBL producers in paediatric patients at Uppsala University Hospital were extracted for comparison. RESULTS: A total of 313 stool specimens were obtained, representing 24.5% of all preschool children in Uppsala city. The carriage rate of ESBL-producing Enterobacteriaceae was 2.9% among these healthy children. The corresponding figure for patients in the same age group was 8.4%. Escherichia coli with CTX-M type enzymes predominated, and only one E. coli isolate carried genes-encoding CMY. CTX-M-producing E. coli isolates with identical genotypes were found in children with no familial relation at two different preschools. CONCLUSIONS: Using diapers, the prevalence of ESBL-producing Enterobacteriaceae in children was quickly established, and, most likely, a transmission of ESBL-producing E. coli was for the first time documented between children at the same preschool.

Bartonella infections in deer keds (Lipoptena cervi) and moose (Alces alces) in Norway.

Infections with Bartonella spp. have been recognized as emerging zoonotic diseases in humans. Large knowledge gaps exist, however, relating to reservoirs, vectors, and transmission of these bacteria. We describe identification by culture, PCR, and housekeeping gene sequencing of Bartonella spp. in fed, wingless deer keds (Lipoptena cervi), deer ked pupae, and blood samples collected from moose, Alces alces, sampled within the deer ked distribution range in Norway. Direct sequencing from moose blood sampled in a deer ked-free area also indicated Bartonella infection but at a much lower prevalence. The sequencing data suggested the presence of mixed infections involving two species of Bartonella within the deer ked range, while moose outside the range appeared to be infected with a single species. Bartonella were not detected or cultured from unfed winged deer keds. The results may indicate that long-term bacteremia in the moose represents a reservoir of infection and that L. cervi acts as a vector for the spread of infection of Bartonella spp. Further research is needed to evaluate the role of L. cervi in the transmission of Bartonella to animals and humans and the possible pathogenicity of these bacteria for humans and animals.

On the etiology of type 1 diabetes: a new animal model signifying a decisive role for bacteria eliciting an adverse innate immunity response.

The cause of type 1 diabetes (T1D) remains unknown; however, a decisive role for environmental factors is recognized. The increased incidence of T1D during the last decades, as well as regional differences, is paralleled by differences in the intestinal bacterial flora. A new animal model was established to test the hypothesis that bacteria entering the pancreatic ductal system could trigger ß-cell destruction and to provide new insights to the immunopathology of the disease. Obtained findings were compared with those present in two patients dying at onset of T1D. Different bacterial species, present in the human duodenum, instilled into the ductal system of the pancreas in healthy rats rapidly induced cellular infiltration, consisting of mainly neutrophil polymorphonuclear cells and monocytes/macrophages, centered around the pancreatic ducts. Also, the islets of Langerhans attracted polymorphonuclear cells, possibly via release of IL-6, IL-8, and monocyte chemotactic protein 1. Small bleedings or large dilatations of the capillaries were frequently found within the islets, and several ß-cells had severe hydropic degeneration (ie, swollen cytoplasm) but with preserved nuclei. A novel rat model for the initial events in T1D is presented, revealing marked similarities with the morphologic findings obtained in patients dying at onset of T1D and signifying a decisive role for bacteria in eliciting an adverse innate immunity response. The present findings support the hypothesis that T1D is an organ-specific inflammatory disease.

Human-associated extended-spectrum ß-lactamase in the Antarctic.

Escherichia coli bacteria with extended-spectrum ß-lactamase (ESBL) type CTX-M resistance were isolated from water samples collected close to research stations in Antarctica. The isolates had bla(CTX-M-1) and bla(CTX-M-15) genotypes and sequence types (ST) indicative of a human-associated origin. This is the first record of ESBL-producing enterobacteria from Antarctica.

Migratory birds, ticks, and Bartonella.

Bartonella spp. infections are considered to be vector-borne zoonoses; ticks are suspected vectors of bartonellae. Migratory birds can disperse ticks infected with zoonotic pathogens such as Rickettsia and tick-borne encephalitis virus and possibly also Bartonella. Thus, in the present study 386 tick specimens collected in spring 2009 from migratory birds on the Mediterranean islands Capri and Antikythera were screened for Bartonella spp. RNA. One or more ticks were found on 2.7% of the birds. Most ticks were Hyalomma rufipes nymphs and larvae with mean infestation rates of 1.7 nymphs and 0.6 larvae per infested bird. Bartonella spp. RNA was not detected in any of the tick specimens.

Arsenic trioxide influences viral replication in target organs of coxsackievirus B3-infected mice.

New antiviral agents are urgently needed. Based on in vitro studies, arsenic trioxide (As2O3) seems to affect viral replication, although this has been studied only marginally in vivo. In this study the replication of coxsackievirus B3 (CVB3) was studied in Balb/c mice administered 1 mg As2O3/kg bw once daily during 7 days of infection and in Vero cells exposed for 3 or 5 days to 0.4, 2 or 4 µM As2O3. Viral RNA was measured by reverse transcription PCR (RT-PCR) (in vitro and in vivo) and arsenic concentration was measured by inductively coupled plasma-mass spectrometry (ICP-MS) (in vivo). In vivo, As2O3 decreased viral RNA in the brain on days 3 (by 81%; p < 0.05) and 7 (by 97%; p < 0.01) and in the pancreas on day 7 (by 75%; p < 0.05), two of the target organs of this infection. The results were confirmed in vitro, where As2O3 dose-dependently reduced viral RNA, with the effect being more pronounced in the surrounding culture medium than inside the infected cells, indicating an impaired virion release. Thus, As2O3 reduced CVB3 replication both in vitro and in vivo, indicating that As2O3 is a viable option in the pursuit of new therapeutic agents against viral infections.

Arsenic trioxide affects the trace element balance in tissues in infected and healthy mice differently.

BACKGROUND: Acquired infections are common in cancer patients. As2O3 treatment and infections affect the body's trace element balance. However, it is unknown whether concomitant infections cause adverse element interactions that endanger the safety and therapeutic effect of As2O3. MATERIALS AND METHODS: Coxsackievirus B3-infected mice were treated with 1.0 mg As2O3/kg bw for 3, 5 or 7 days. Arsenic, magnesium, iron, copper, zinc and selenium were measured (ICP-MS) in serum, heart, lung, liver, pancreas, kidney, intestine and brain. Virus in serum was followed by RT-PCR. RESULTS: The infection increased As in all organs except the intestine, whereas selenium concentration decreased in all organs except the heart and brain. The infection markedly reduced magnesium in the heart. CONCLUSION: As2O3 treatment results in pronounced differences in trace elements between healthy and infected individuals. This finding is important to consider, regarding treatment safety and efficacy, when As2O3 therapy is used in the clinical setting.

Viral RNA kinetics is associated with changes in trace elements in target organs of Coxsackie virus B3 infection.

Trace elements are pivotal for the host defense, as well as potentially important for viral replication and virulence. Studies of sequential changes in viral replication in target organs of infection are sparse and a possible association with changes in specific trace elements is unknown. In this study Balb/c mice were infected with Coxsackie virus B3 (CVB3). Results indicated that sequential changes in viral replication (RT-PCR) were related to changes in trace element (arsenic, copper, iron, selenium and zinc) concentrations (as determined by ICP-MS) on days 3, 5 and 7 of the infection in serum, heart, lung, liver, pancreas, kidney, spleen, intestine and brain. After an initial viral peak on day 3, viral load drastically decreased in all organs, i.e. by >99% (serum), 97% (lung), 98% (liver), 60% (pancreas), 95% (kidney) and 93% (spleen), except in the heart, intestine and brain in which viral load increased after day 3. Selenium decreased in all organs except the heart while arsenic decreased in all organs except the kidney, spleen and brain. Moreover, selenium was negatively correlated to viral load in serum, liver, pancreas and intestine. To conclude, these findings give evidence that trace elements are directly involved in the replication of CVB3.

Sequential effects of daily arsenic trioxide treatment on essential and nonessential trace elements in tissues in mice.

Despite arsenic's (As) toxic potential, arsenic trioxide (As2O3) is used as a safe and effective treatment in acute promyelocytic leukaemia. However, it is unknown whether such therapy influences the balance of other trace elements in the body. In this study, mice were treated intraperitoneally daily with 1.0 mg As2O3/kg bw for 3, 5 or 7 days. As, and seven essential and nonessential trace elements with the potential to interact with As, were measured through inductively coupled plasma-mass spectrometry in serum, heart, lung, liver, pancreas, kidney, intestine and brain. As2O3 supplementation increased As in all target tissues on day 3, thereafter reaching an almost steady state. The major findings in other elements were a sequential decrease in serum zinc (on day 7 by 64%; P<0.001), and a decrease in selenium in the pancreas on day 3 (9%; P<0.05), in the intestine on day 3 (30%; P<0.001) and finally, in the brain on days 5 (12%; P<0.05) and 7 (15%; P<0.01). Changes in magnesium, iron, copper, cadmium and mercury were minor and inconsistent. This study suggests that supplementation with other trace elements may be beneficial when As2O3 treatment regimens are used in the clinic.

Trace element balance is changed in infected organs during acute Chlamydophila pneumoniae infection in mice.

Most infectious diseases are accompanied by changed levels of several trace elements in the blood. However, sequential changes in trace elements in tissues harbouring bacterial infections have not been studied. In the present study the respiratory pathogen Chlamydophila pneumoniae (C. pneumoniae), adapted to C57BL/6J mice, was used to study whether the balance of trace elements is changed in infected organs. Bacteria were quantitatively measured by real-time PCR in the blood, lungs, liver, aorta, and heart on days 2, 5, and 8 of the infection. Concentrations of 13 trace elements were measured in the liver, heart, and serum by inductively coupled plasma mass-spectrometry (ICP-MS). Infected mice developed expected clinical signs of disease and bacteria were found in lungs, liver, and heart on all days. The number of bacteria peaked on day 2 in the heart and on day 5 in the liver. The copper/zinc (Cu/Zn) ratio in serum increased as a response to the infection. Cu increased in the liver but did not change in the heart. Iron (Fe) in serum decreased progressively, whereas in the heart it tended to increase, and in the liver it progressively increased. C. pneumoniae may thus cause a changed trace element balance in target tissues of infection that may be pivotal for bacterial growth.

Tissue uptake of mercury is changed during the course of a common viral infection in mice.

Mercury (Hg) has been shown to have immunotoxic effects and to influence the severity of infection. However, the impact of infection on the normal Hg homeostasis in different target organs involved in the disease process has not been studied. In this study, Hg was measured through inductively coupled plasma-mass spectrometry (ICP-MS) in the intestine, serum, liver, and brain on days 3, 6, and 9 of coxsackievirus B3 (CVB3) infection in female Balb/c mice. The severity of the infection was assessed from clinical signs of disease and the number of virus particles in infected organs. CVB3 and gene expression of metallothionein 1 (MT1) was measured by reverse transcription-polymerase chain reaction (RT-PCR). Gene expression of MT1 increased and peaked on day 3 in the brain (93%, p<0.01) and liver (19-fold, p<0.01) and on day 6 in the intestine (seven-fold, p<0.01). This peak in MT1 in the liver and brain corresponded to the peak in virus numbers in these tissues. Hg in the intestine and serum tended to decrease on all days of infection. The maximum decrease, in comparison with non-infected mice, occurred in the intestine (78%, p<0.001) on day 9 and in serum (50%, p<0.05) on day 6. However, in the brain, Hg increased by 52% (p<0.05) on day 6. Hg went unchanged in the liver. An infection-induced increase of Hg in the brain but unchanged level in the liver may be due to the peak of virus replication and an associated infection-induced expression of MT1. Moreover, the decrease of Hg in serum and the intestine but a concomitant intestinal increase in MT1 on day 6 may reflect a flux and increased retention of Hg to infected organs such as the brain. The pathophysiological interpretation of these preliminary findings requires further research.

Coxsackievirus B3 infection and PBDE exposure causes organ-specific effects on CYP-gene expression in the mouse.

Common viral infections have been shown to change the tissue distribution of xenobiotics, including polybrominated diphenyl ethers (PBDEs). In previous studies, it has been shown that CYP2B gene expression is induced after PBDE exposure whereas coxsackievirus B3 (CBV3) infection suppresses the expression of CYP-gene expression in the liver. In the present study, CVB3 adapted to Balb/c mice was used to study the combined effects of infection and exposure to pure BDE-99 or the commercial mixture Bromkal on CYP1A1 and CYP2B expression in the lungs and pancreas on day 3 of the infection. The quantitative gene expression of virus, CYP1A1 and CYP2B was measured by real-time polymerase chain reaction (RT-PCR). PBDE exposure in the non-infected mice tended to increase CYP2B expression in the lungs but not in the pancreas. Infection in both non-exposed and PBDE-exposed mice increased CYP2B expression in the lungs but was non-detectable in the pancreas. In the non-infected mice PBDE exposure left the CYP1A1 expression unaltered in both the lungs and pancreas. Infection in both non-exposed and PBDE-exposed mice tended to decrease the gene expression of CYP1A1 in the lungs but to induce it in the pancreas. A correlation between the amount of virus and the gene expression of CYP2B was found in the lungs. However, no effects of PBDE on virus replication were observed in any organ. In conclusion, viral infection affects CYP-gene expression differently in the pancreas and lungs whereas PBDE-induced effects were not obvious. The organ-specific change in gene expression could explain a changed tissue distribution of xenobiotics during infection.

Viral infection and PBDE exposure interact on CYP gene expression and enzyme activities in the mouse liver.

In the present study coxsackievirus B3 (CVB3) adapted to Balb/c mice was used to examine whether infection affects xenobiotic-metabolising CYP1A1 and CYP2B gene expression (measured by RT-PCR) and the corresponding enzyme activities of ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-depentylase (PROD), as observed on day 3 of infection. To study the simultaneous effects of xenobiotic exposure, mice were administered the polybrominated diphenyl ether (PBDE) compounds BDE-99 (single congener) and Bromkal 70-5 DE (commercial mixture). Serum thyroxine levels were also measured. High numbers of CVB3 were found in the livers of infected mice but no significant effects of PBDE on virus replication were observed. In infected mice gene expression and CYP activities were decreased in comparison with non-infected mice, especially for CYP2B. PBDE exposure in the non-infected mice was characterised by an increase in both CYP2B and PROD levels/activities, whereas CYP1A levels increased and EROD activity decreased. In general, PBDE exposure in the infected mice did not increase EROD and PROD activities to the same extent as in the non-infected exposed mice. Infected mice exposed to BDE-99 showed significantly higher CYP2B and PROD levels than both the infected non-exposed and Bromkal-exposed groups. T(4) levels were greatly decreased by infection and a tendency of reduced T(4) levels after PBDE exposure could be observed in non-infected mice. In conclusion, infection reduced the detoxifying capacity of the liver and the serum T(4) levels. PBDE exposure can modify these effects. Notably, in the infected mice differences between BDE-99 and Bromkal were observed on CYP2B gene expression and PROD activity.