Marked elevation of cerebrospinal fluid white blood cell count: An unusual case of Streptococcus pneumoniae meningitis, differential diagnosis, and a brief review of current epidemiology and treatment recommendations

A case of fatal acute bacterial meningoencephalitis with extremely high cerebrospinal fluid white blood cell count

Acute bacterial meningoencephalitis is still prevalent despite the widespread vaccination and still fatal despite the advances in antimicrobial therapy. Identifying patients at risk, lowering the threshold of clinical diagnosis and early treatment of such a curable disease will save patients' lives.

High-Throughput Cell Concentration Using A Piezoelectric Pump in Closed-Loop Viscoelastic Microfluidics

Cell concentration is a critical process in biological assays and clinical diagnostics for the pre-treatment of extremely rare disease-related cells. The conventional technique for sample preconcentration and centrifugation has the limitations of a batch process requiring expensive and large equipment. Therefore, a high-throughput continuous cell concentration technique needs to be developed. However, in single-pass operation, the required concentration ratio is hard to achieve. In this study, we propose a closed-loop continuous cell concentration system using a viscoelastic non-Newtonian fluid. For miniaturized and integrated systems, two piezoelectric pumps were adopted. The pumping capability generated by a piezoelectric pump in a microfluidic channel was evaluated depending on the applied voltage, frequency, sample viscosity, and channel length. The concentration performance of the device was evaluated using 13 μm particles and white blood cells (WBCs) with different channel lengths and voltages. In the closed-loop system, the focused cells collected at the center outlet were sent back to the inlet, while the buffer solution was removed to the side outlets. Finally, to expand the clinical applicability of our closed-loop system, WBCs in lysed blood samples with 70% hematocrit and prostate cancer cells in urine samples were used. Using the closed-loop system, WBCs were concentrated by ~63.4 ± 0.8-fold within 20 min to a final volume of 160 μL using 10 mL of lysed blood sample with 70% hematocrit (~3 cP). In addition, prostate cancer cells in 10 mL urine samples were concentrated by ~64.1-fold within ~11 min due to low viscosity (~1 cP).

Is Immature Granulocyte Count a Potential Prognostic Marker for Upper Gastrointestinal Tract Bleeding? A New Road to Explore

How to cite this article: Prabu NR, Patil VP. Is Immature Granulocyte Count a Potential Prognostic Marker for Upper Gastrointestinal Tract Bleeding? A New Road to Explore. Indian J Crit Care Med 2020;24(9):750-752.

Neutrophil left shift and white blood cell count as markers of bacterial infection

Neutrophil left shift and white blood cell (WBC) count are routine laboratory tests used to assess neutrophil state, which depends on supply from the bone marrow and consumption in the tissues. If WBC count is constant, the presence of left shift indicates an increase of neutrophil consumption that is equal to an increase of production. A decrease in WBC count indicates that neutrophil consumption surpasses supply. During a bacterial infection, large numbers of neutrophils are consumed. Thus, from onset of infection to recovery, dynamic changes occur in WBC count and left shift data, reflecting the mild to serious condition of the bacterial infection. Although various stimuli in healthy and pathological conditions also cause left shift, a change as sudden and significant is only seen in bacterial infection. Left shift does not occur in the extremely early or late phases of infection; therefore, assessing data from a single time point is unsuitable for diagnosing a bacterial infection. We argue that time-series data of left shift and WBC count reflect real-time neutrophil consumption during the course of a bacterial infection, allowing more accurate evaluation of patient condition.

An improved SELEX technique for selection of DNA aptamers binding to M-type 11 of Streptococcus pyogenes

Streptococcus pyogenes is a clinically important pathogen consisting of various serotypes determined by different M proteins expressed on the cell surface. The M type is therefore a useful marker to monitor the spread of invasive S. pyogenes in a population. Serotyping and nucleic acid amplification/sequencing methods for the identification of M types are laborious, inconsistent, and usually confined to reference laboratories. The primary objective of this work is to develop a technique that enables generation of aptamers binding to specific M-types of S. pyogenes. We describe here an in vitro technique that directly used live bacterial cells and the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) strategy. Live S. pyogenes cells were incubated with DNA libraries consisting of 40-nucleotides randomized sequences. Those sequences that bound to the cells were separated, amplified using polymerase chain reaction (PCR), purified using gel electrophoresis, and served as the input DNA pool for the next round of SELEX selection. A specially designed forward primer containing extended polyA20/5Sp9 facilitated gel electrophoresis purification of ssDNA after PCR amplification. A counter-selection step using non-target cells was introduced to improve selectivity. DNA libraries of different starting sequence diversity (10(16) and 10(14)) were compared. Aptamer pools from each round of selection were tested for their binding to the target and non-target cells using flow cytometry. Selected aptamer pools were then cloned and sequenced. Individual aptamer sequences were screened on the basis of their binding to the 10 M-types that were used as targets. Aptamer pools obtained from SELEX rounds 5-8 showed high affinity to the target S. pyogenes cells. Tests against non-target Streptococcus bovis, Streptococcus pneumoniae, and Enterococcus species demonstrated selectivity of these aptamers for binding to S. pyogenes. Several aptamer sequences were found to bind preferentially to the M11 M-type of S. pyogenes. Estimated binding dissociation constants (Kd) were in the low nanomolar range for the M11 specific sequences; for example, sequence E-CA20 had a Kd of 7±1 nM. These affinities are comparable to those of a monoclonal antibody. The improved bacterial cell-SELEX technique is successful in generating aptamers selective for S. pyogenes and some of its M-types. These aptamers are potentially useful for detecting S. pyogenes, achieving binding profiles of the various M-types, and developing new M-typing technologies for non-specialized laboratories or point-of-care testing.

Fulminant pneumococcal meningitis manifesting as acute abdomen

In January 2007, a 21-year-old woman presented to the emergency department with abdominal pain, fever, nausea, vomiting and diarrhoea for 6 hours. She had no other associated symptoms with unrevealing previous history. On examination she was ill-looking, conscious and oriented, with a temperature of 39.2°C, blood pressure 96/52 mmHg and pulse rate 140 beats per minute, and had clinical evidence of dehydration. Her abdomen was rigid, mainly in the right lower quadrant, with sluggish bowel sounds. The rest of the clinical examination was normal including the neurological examination. The results of blood tests were white blood cell count= 19 × 109/litre (normal range (NR) 4–11× 109/litre) with 91% neutrophils, sodium 138 mmol/litre (NR 135–145 mmol/litre), potassium 3.4 mmol/litre (NR 3.5–5 mmol/litre), serum glucose 7.1 mmol/litre (NR 4–6 mmol/litre). A chest radiograph was normal; the abdominal X-ray showed dilated bowel loops and no free gas under the diaphragm.

The initial differential diagnosis was gastroenteritis vs acute appendicitis. The normal abdominal ultrasound and normal computed tomography (CT) scan made the diagnosis of appendicitis very unlikely. The patient was admitted as a case of gastroenteritis and improved on intravenous hydration, pain control, and intravenous ciprofloxacin 400 mg 12-hourly and metronidazole 500 mg 8-hourly.

Twenty-nine hours after admission she complained of headache, became increasingly lethargic and febrile (39°C), and the abdomen was still rigid. Her level of consciousness deteriorated with Glasgow Coma Scale of 8/15 (eye opening 2/4, verbal response 2/5 and motor response 4/6) and nuchal rigidity was obvious at this stage. Formal neurological exam was not feasible because of the patient's condition, but she was moving all her limbs and had no obvious clinical evidence of lateralizing signs.

Bacterial meningitis was suspected and treated with intravenous dexamethasone 6-hourly, ceftriaxone 2 g 12-hourly and vancomycin 1 g 12-hourly. An hour later, while awaiting a CT scan she developed tonic clonic seizures with fixed dilated pupils and was transferred to the intensive care unit where she was immediately intubated and ventilated. CT of the brain was normal (Figure 1). Lumbar puncture revealed a total cell count of 80 × 109/litre with 52% polymorphs and 48% mononuclear cells, protein concentration 8.3 g/litre (NR 0.1–0.4 g/litre), glucose concentration was <0.03 mmol/litre (NR <20 mg/dl), and Gram staining of CSF showed Gram-positive diplococci. Subsequently, CSF and blood cultures yielded Streptococcus pneumoniae sensitive to penicillin so she was given intravenous penicillin G 4 million units 4-hourly.

Over 2 days she developed septic shock requiring inotropes, and remained in a deep coma. Magnetic resonance imaging of the brain showed diffuse leptomeningeal enhancement and multiple infarctions in both cerebral hemispheres, the brainstem and cerebellum (Figure 2). Unfortunately the patient never regained consciousness and 5 days after presentation she died despite all supportive measures.

Oxidative stress in cerebrospinal fluid of patients with aseptic and bacterial meningitis

This study aimed to determine whether patients with aseptic and bacterial meningitis presented alterations in oxidative stress parameters of cerebrospinal fluid (CSF). A total of 30 patients were used in the research. The CSF oxidative stress status has been evaluated through many parameters, such as lipid peroxidation through thiobarbituric acid reactive substances (TBARS) and antioxidant defense systems such as superoxide dismutase (SOD), glutathione S-transferase (GST), reduced glutathione (GSH) and ascorbic acid. TBARS levels, SOD and GST activity increase in aseptic meningitis and in bacterial meningitis. The ascorbic acid concentration increased significantly in patients with both meningitis types. The reduced glutathione levels were reduced in CSF of patients with aseptic and bacterial meningitis. In present study we may conclude that oxidative stress contributes at least in part to the severe neurological dysfunction found in meningitis.

Adenine nucleotide hydrolysis in patients with aseptic and bacterial meningitis

The meningitis is a disease with high mortality rates capable to cause neurologic sequelae. The adenosine (the final product of ATP hydrolysis by ectonucleotidases), have a recognized neuroprotective actions in the central nervous system (CNS) in pathological conditions. The aim of the present study was evaluate the adenine nucleotides hydrolysis for to verify one possible role of ATP, ADP and AMP hydrolysis in inflammatory process such as meningitis. The hydrolysis was verified in cerebrospinal fluid (CSF) from human patients with aseptic and bacterial meningitis. Our results showed that the ATP hydrolysis was reduced 12.28% (P < 0.05) in bacterial meningitis and 22% (P < 0.05) in aseptic meningitis. ADP and AMP hydrolysis increased 79.13% (P < 0.05) and 26.37% (P < 0.05) in bacterial meningitis, respectively, and 57.39% (P < 0.05) and 42.64% (P < 0.05) in aseptic meningitis, respectively. This may be an important protective mechanism in order to increase adenosine production.

Rapidly fatal infections

Emergency physicians are trained to separate “sick” from “not sick” patients during their training. Nevertheless, every emergency physician will face situations in which early intervention is critical to their patient's outcome. Infectious diseases are responsible for many of these potentially poor outcomes. This article discusses early identification and treatment for several rapidly fatal infections, including two newly identified travel-related illnesses.