Microbiology

Contribution of diagnostic syndromic panels to emergency management Pediatric infectious: regarding an outbreak of Mycoplasma pneumoniae.

Atypical pneumonia is a common cause of respiratory infection in the paediatric population with Mycoplasma pneumoniae being one of the main aetiological agents. Rapid and accurate identification of M. pneumoniae is essential to guide antibiotic treatment, especially in the context of epidemic outbreaks, where clinical diagnosis may be non-specific. The introduction of multiplex syndromic panels in the emergency microbiology laboratory allows rapid and simultaneous detection of multiple pathogens. We have shown that this has a significant impact on antimicrobial prescribing in the paediatric population, reducing the unnecessary use of broad-spectrum antibiotics and favouring a targeted therapeutic approach, as the result is available in approximately 2 hours.

Whooping cough is on the rise: Epidemiological situation in the Vallès area

Whooping cough, caused by the bacterium Bordetella pertussis, is an endemic disease that has re-emerged in Catalonia and worldwide since the end of 2023. It is characterized by cyclical outbreaks every 3-5 years and can affect people of all ages. Neither natural infection with B. pertussis nor vaccination confers long-lasting immunity, so reinfections are frequent.

Transmission occurs mainly through direct contact and inhalation of droplets from infected people when coughing. In infants under 6 months of age, the disease presents a higher risk of complications (pneumonia, encephalopathy, sepsis) and can cause the death of the patient.

Diagnosis is made by serological tests (indirect) or real-time PCR (direct), the latter being the most specific and currently the main method for diagnosing this disease. Since the end of 2023, more than 16,000 samples have been processed in our Laboratory with a notable increase in cases in children aged 10 to 14 years throughout the epidemic outbreak.

The use of rapid diagnostic tests are useful for the management of patients with acute pathology who consult in the emergency room,as long as we can change the therapeutic attitude. Indiscriminate use can lead to a misinterpretation of results.

In the ​​microbiology area and paediatrics, we have drawn up a document with indications for use of the Filmarray™ respiratory panel in paediatrics.

Changes in the reporting of antibiotic susceptibility in the reporting of

microbiology New interpretation of susceptibility categories S, I and

R.

As of June 2022, the categories used to generate Microbiology culture sensitivity reports in Catlab have been modified in order to include the new recommendations of the European Committee for Antimicrobial Susceptibility Testing (EUCAST).

Thus the less problematic definitions Susceptible(S) and Resistant(R) remain, but the term Intermediate(I) disappears and the term Sensitive: Susceptible to Increased Exposure: S(EI) begins to be used. This new term refers to microorganisms where treatment will increase therapeutic success by increasing antibiotic exposure, dosage or concentration at the site of infection. At Catlab, the Microbiology department remains available to clarify any doubts.

Microbiological diagnostic of sepsia

Early detection of this organ dysfunction is key to reducing complications that can ultimately lead to patient death. In order to reduce response time, at Catlab, two algorithms are used from positive blood culture,thus allowing positive results and antibiogram to be informed as soon as possible.

Etiological diagnosis of onychomycosis using molecular biology techniques

Onychomycosis is the infection of the nail caused by fungus. It is the most common nail infection worldwide. Most are caused by dermatophyte fungi. The diagnosis is based on microscopic observation and culture, techniques with many limitations such as low sensitivity or slowness of cultures. For these reasons at Catlab, the appropriateness to introduce molecular techniques that significantly increase sensitivity and shorten response time was assessed.

Infection control measures at hospital setting have varied over time and pathogenic bacteria. However, recommendations of the European Society of Microbiology and Infectious Diseases (ESCMID) suggest the implementation of contact precautions in patients colonized or infected with multidrug-resistant bacteria.

Thus, at the University Hospital Mutua de Terrassa, based on clinical experience and several bibliographic reviews,changes have been made in the policy of contact precautions in endemic situations according to involved bacteria.

Lessons learned from SARS-CoV-2 humoral immune response

SARS-CoV-2 serology, using antibody detection may be useful in several scenarios, where the detection of active infection (PCR) may not be sufficient, such as seroprevalence studies, diagnosis of patients with compatible symptomatology and negative PCR or in the control of vaccine efficacy, among other cases.

Catlab has carried out antibody detection using high-performance ELlSA techniques (chemiluminescence, CLIA), making serological diagnosis a very useful tool for a better understanding of humoral response to this new virus.

MICROBIOLOGY-Sexually Trasnmitted Diseases. Microbylogical diagnosis

Sexually Transmitted Infections (STIs) are a Public Health problem. Every year, approximately 500 million people suffer from chlamydia, gonorrhea, syphilis or trichomoniasis. The microbiological diagnosis of STIs allows not only to detect and treat symptomatic patients but also to detect asymptomatic contacts in order to prevent transmission and reinfection.

At Catlab, depending on each type of sample received a microscopic examination, microbiological culture and detection by nucleic acid amplification techniques are performed in order to optimize the detection of microorganisms involved in these diseases.

MICROBIOLOGY - Response of the Microbiology area against SARS-CoV-2(COVID19)

The reference technique for performing the microbiological diagnosis of SARS-CoV-2 is real-time PCR, which allows the detection of various virus genes with a sensitivity greater than 98%. At Catlab, various organizational changes were made to deal with the situation, and offer a SARS-CoV-2 diagnostic service 24 hours a day and 7 days a week.