Multiple Mycobacterium tuberculosis infections in an HIV-infected patient

Mycobacterial colonies of two different morphologies were isolated from one sputum sample of a HIV-positive patient. One morphological type was resistant to streptomycin (STR) and susceptible to isoniazid (INH), while the other isolate with different colony morphology was resistant to both of these anti-TB drugs. A mycobacterial isolate of one pus from a lymph node sample was resistant to these two anti-TB drugs, while the other isolate from another pus sample was resistant to STR but susceptible INH. IS6110 RFLP based finger printing revealed that the HIV-positive patient was infected with different strains of Mycobacterium tuberculosis. A subculture of isolates on solid medium is useful to examine mixed infection.     

Microevolution of Mycobacterium tuberculosis in a Tuberculosis Patient

Five Mycobacterium tuberculosis isolates were obtained from three body sites from a Dutch patient. The isolates displayed a single genotype by 24-locus MIRU-VNTR typing (except for a single locus not amplified from one isolate) but were differentiated by small variations in IS6110 fingerprints, spoligotypes, 6 hypervariable MIRU-VNTR loci, and/or DiversiLab profiles, revealing patterns of microevolution in a clonal infection.     

Tuberculosis Caused by Mycobacterium orygis in Dairy Cattle and Captured Monkeys in Bangladesh: a New Scenario of Tuberculosis in South Asia

Mycobacterium orygis, commonly known as the oryx bacillus and a newly proposed Mycobacterium tuberculosis complex subspecies, was isolated from 18 cattle in a dairy farm and two captured rhesus monkeys in a zoo in Bangladesh. All the infected animals had tuberculosis lesions in their lungs, suggesting transmission and infection with M. orygis by an airborne route. The 20 isolates were analysed using a range of conventional and molecular typing methods, and RD‐deletion typing and sequencing of selected genes confirmed the isolates as M. orygis. Multiple‐locus variable‐number tandem repeat analysis (MLVA) allowed the isolates to be divided into three clusters based on the relatedness of their MLVA profiles. The two monkey isolates shared the same MLVA pattern with 15 of the cattle isolates, whereas the remaining three cattle isolates had different patterns, even though the latter animals had been kept in the same dairy farm. The diversity observed among isolates may suggest the bacteria have been established in this area for a long period. This study along with other recent findings that report the detection of M. orygis from animals as well as humans originating from South Asia potentially indicate endemic distribution of M. orygis in South Asia.     

New diagnostic criteria for gestational diabetes mellitus and their impact on the number of diagnoses and pregnancy outcomes

Aims/hypothesis

Detection and management of gestational diabetes mellitus (GDM) are crucial to reduce the risk of pregnancy-related complications for both mother and child. In 2013, the WHO adopted new diagnostic criteria for GDM to improve pregnancy outcomes. However, the evidence supporting these criteria is limited. Consequently, these new criteria have not yet been endorsed in the Netherlands. The aim of this study was to determine the impact of these criteria on the number of GDM diagnoses and pregnancy outcomes.

Methods

Data were available from 10,642 women who underwent a 75 g OGTT because of risk factors or signs suggestive of GDM. Women were treated if diagnosed with GDM according to the WHO 1999 criteria. Data on pregnancy outcomes were obtained from extensive chart reviews from 4,431 women and were compared between women with normal glucose tolerance (NGT) and women classified into the following groups: (1) GDM according to WHO 1999 criteria; (2) GDM according to WHO 2013 criteria; (3) GDM according to WHO 2013 fasting glucose threshold, but not WHO 1999 criteria; and (4) GDM according to WHO 1999 2 h plasma glucose threshold (2HG), but not WHO 2013 criteria.

Results

Applying the new WHO 2013 criteria would have increased the number of diagnoses by 45% (32% vs 22%) in this population of women at higher risk for GDM. In comparison with women with NGT, women classified as having GDM based only on the WHO 2013 threshold for fasting glucose, who were not treated for GDM, were more likely to have been obese (46.1% vs 28.1%, p?<?0.001) and hypertensive (3.3% vs 1.2%, p?<?0.001) before pregnancy, and to have had higher rates of gestational hypertension (7.8% vs 4.9%, p?=?0.003), planned Caesarean section (10.3% vs 6.5%, p?=?0.001) and induction of labour (34.8% vs 28.0%, p?=?0.001). In addition, their neonates were more likely to have had an Apgar score <7 at 5 min (4.4% vs 2.6%, p?=?0.015) and to have been admitted to the Neonatology Department (15.0% vs 11.1%, p?=?0.004). The number of large for gestational age (LGA) neonates was not significantly different between the two groups. Women potentially missed owing to the higher 2HG threshold set by WHO 2013 had similar pregnancy outcomes to women with NGT. These women were all treated for GDM with diet and 20.5% received additional insulin.

Conclusions/interpretation

Applying the WHO 2013 criteria will have a major impact on the number of GDM diagnoses. Using the fasting glucose threshold set by WHO 2013 identifies a group of women with an increased risk of adverse outcomes compared with women with NGT. We therefore support the use of a lower fasting glucose threshold in the Dutch national guideline for GDM diagnosis. However, adopting the WHO 2013 criteria with a higher 2HG threshold would exclude women in whom treatment for GDM seems to be effective.

     

Evaluation of yield of currently available diagnostics by sample type to optimize detection of respiratory pathogens in patients with a community‐acquired pneumonia

Background

For the detection of respiratory pathogens, the sampling strategy may influence the diagnostic yield. Ideally, samples from the lower respiratory tract are collected, but they are difficult to obtain.

Objectives

In this study, we compared the diagnostic yield in sputum and oropharyngeal samples (OPS) for the detection of respiratory pathogens in patients with community-acquired pneumonia (CAP), with the objective to optimize our diagnostic testing algorithm.

Methods

Matched sputum samples, OPS, blood cultures, serum, and urine samples were taken from patients (>18 years) with CAP and tested for the presence of possible respiratory pathogens using bacterial cultures, PCR for 17 viruses and five bacteria and urinary antigen testing.

Results

When using only conventional methods, that is, blood cultures, sputum culture, urinary antigen tests, a pathogen was detected in 49·6% of patients (n = 57). Adding molecular detection assays increased the yield to 80%. A pathogen was detected in 77 of the 115 patients in OPS or sputum samples by PCR. The sensitivity of the OPS was lower than that of the sputum samples (57% versus 74%). In particular, bacterial pathogens were more often detected in sputum samples. The sensitivity of OPS for the detection of most viruses was higher than in sputum samples (72% versus 66%), except for human rhinovirus and respiratory syncytial virus.

Conclusion

Addition of PCR on both OPS and sputum samples significantly increased the diagnostic yield. For molecular detection of bacterial pathogens, a sputum sample is imperative, but for detection of most viral pathogens, an OPS is sufficient.     

Mycobacterium tuberculosis Beijing genotype strains associated with febrile response to treatment.

DNA fingerprinting has demonstrated predominance of the Beijing genotype among Mycobacterium tuberculosis strains isolated in Southeast Asia. We prospectively examined the occurrence of Beijing genotype strains in tuberculosis patients in Indonesia. Early in treatment, patients infected with Beijing genotype strains more often had fever unrelated to disease severity, toxicity, or drug resistance, indicating that Beijing genotype strains may have specific pathogenic properties.     

Unphosphorylated STAT3 modulates alpha7 nicotinic receptor signaling and cytokine production in sepsis

The role of STAT3 in infectious diseases remains undetermined, in part because unphosphorylated STAT3 has been considered an inactive protein. Here, we report that unphosphorylated STAT3 contributes to cholinergic anti‐inflammation, prevents systemic inflammation, and improves survival in sepsis. Bacterial endotoxin induced STAT3 tyrosine phosphorylation in macrophages. Both alpha7 nicotinic receptor (alpha7nAChR) activation and inhibition of JAK2 blunt STAT3 phosphorylation. Inhibition of STAT3 phosphorylation mimicked the alpha7nAChR signaling, inhibiting NF‐κB and cytokine production in macrophages. Transfection of macrophages with the dominant‐negative mutant STAT3F, to prevent its tyrosine phosphorylation, reduced TNF production but did not prevent the alpha7nAChR signaling. However, inhibition of STAT3 protein expression enhanced cytokine production and abrogated alpha7nAChR signaling. Alpha7nAChR controls TNF production in macrophages through a mechanism that requires STAT3 protein expression, but not its tyrosine phosphorylation. In vivo, inhibition of STAT3 tyrosine phosphorylation by stattic prevented systemic inflammation and improved survival in experimental sepsis. Stattic also prevented the production of late mediators of sepsis and improved survival in established sepsis. These results reveal the immunological implications of tyrosine‐unphosphorylated STAT3 in infectious diseases.