Fístula de líquido cefalorraquídeo después de hisopado nasofaríngeo en pandemia COVID-19. A propósito de dos casos

Resumen Uno de los pilares fundamentales en el manejo de la pandemia por SARS-CoV2 es la detección temprana de la presencia del virus en pacientes. El método más utilizado es mediante hisopado nasofaríngeo para amplificar ácidos nucleicos mediante reacción en cadena de polimerasa (PCR). Las complicaciones asociadas a la técnica de hisopado aún no están completamente caracterizadas. Hasta ahora hay un caso reportado internacionalmente de fístula de líquido cefalorraquídeo poshisopado nasofaríngeo. Presentamos dos casos de fístula posterior a dicho examen: el primer caso un paciente de género femenino con sospecha de hipertensión intracraneal idiopática, cuya brecha se reparó quirúrgicamente; el segundo caso un paciente de género masculino con antecedente de hidrocefalia y meningitis neonatal que, al estudio por rinorraquia, se encuentra un meningoencefalocele en el receso frontal derecho, también reparado quirúrgicamente.

Abstract One of the cornerstones in the management of coronavirus pandemic is the early identification of virus presence in patients. The most used test is the nasopharyngeal swab, used to amplify nucleic acids through polymerase chain reaction. Complications with this test have not been completely characterized. Until now, only one international report of cerebrospinal fluid leak has been reported. We present two cases of leak after nasopharyngeal swab test: the first case corresponded to an adult feminine gender patient with suspected idiopathic intracranial hypertension, whose gap was surgically repaired; the second case adult male patient with medical history of hydrocephalus and neonatal meningitis who was further studied for rhinoliquorrhea that showed a meningoencephalocele occupying the right frontal recess.

Nasal carriage of methicillin-resistant Staphylococcus aureus among health-care workers at a tertiary care hospital in Northern India

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to all beta-lactam antibiotics, including penicillins, cephalosporins, carbapenems, and betalactamase inhibitors. MRSA remains a public health problem globally. MRSA infection increases morbidity, risk of mortality, increased financial burden, and loss of productivity. A major source of MRSA in the hospital environment can be asymptomatically colonized health-care workers (HCWs). Objectives: The aim of the study is to screen nasal swabs collected from HCWs of our hospital for colonization with S. aureus and detect methicillin resistance among them. Materials and Methods: In this cross-sectional study, consenting HCWs were consecutively enrolled. Nasal swabs were collected aseptically from study participants and processed using standard microbiological protocols for the recovery of S. aureus and MRSA. Methicillin resistance was detected by cefoxitin disc diffusion method according to the CLSI guidelines. Results: Out of a total of 184 HCWs studied, the prevalence of S. aureus carriage in anterior nares was 14.6%. The overall MRSA prevalence was 3.8%. Highest carriage rates for MRSA were found in laboratory technicians (7.1%) followed by nursing staff (4.4%). The ophthalmology department had the highest MRSA carriage rate of 22%. Conclusions: Our findings demonstrate that nasal carriage of MRSA among HCWs is relatively low in this study compared to other Indian studies done in tertiary care centres. Further studies are needed to evaluate the incidence of infections due to MRSA in this population.

Nasal swab real-time PCR is not suitable for in vivo diagnosis of bovine tuberculosis / A PCR em tempo real de swab nasal não é adequada para o diagnóstico in vivo de tuberculose bovina

Bovine tuberculosis (bTB) is a zoonosis causing economic losses and public health risks in many countries. The disease diagnosis in live animals is performed by intradermal tuberculin test, which is based on delayed hypersensitivity reactions. As tuberculosis has complex immune response, this test has limitations in sensitivity and specificity. This study sought to test an alternative approach for in vivo diagnosis of bovine tuberculosis, based on real-time polymerase chain reaction (PCR). DNA samples, extracted from nasal swabs of live cows, were used for SYBR® Green real-time PCR, which is able to differentiate between Mycobacterium tuberculosis and Mycobacterium avium complexes. Statistical analysis was performed to compare the results of tuberculin test, the in vivo gold standard bTB diagnosis method, with real-time PCR, thereby determining the specificity and sensitivity of molecular method. Cervical comparative test (CCT) was performed in 238 animals, of which 193 had suitable DNA from nasal swabs for molecular analysis, as indicated by amplification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, and were included in the study. In total, 25 (10.5%) of the animals were CCT reactive, of which none was positive in the molecular test. Of the 168 CCT negative animals, four were positive for M. tuberculosis complex at real time PCR from nasal swabs. The comparison of these results generated values of sensitivity and specificity of 0% and 97.6%, respectively; moreover, low coefficients of agreement and correlation (-0.029 and -0.049, respectively) between the results obtained with both tests were also observed. This study showed that real-time PCR from nasal swabs is not suitable for in vivo diagnosis of bovine tuberculosis; thus tuberculin skin test is still the best option for this purpose.(AU)

A tuberculose bovina (bTB) é uma zoonose que causa perdas econômicas e riscos à saúde pública em muitos países. O diagnóstico da doença em animais vivos é realizado pelo teste intradérmico da tuberculina, que é baseado em reações de hipersensibilidade tardia. Como a tuberculose tem resposta imunológica complexa, este teste tem limitações em termos de sensibilidade e especificidade. Este estudo procurou desenvolver uma abordagem alternativa para o diagnóstico in vivo da tuberculose bovina, com base na reação em cadeia da polimerase (PCR) em tempo real. As amostras de DNA, extraídas de suabes nasais de vacas vivas, foram usadas para PCR em tempo real com SYBR® Green, capaz de diferenciar os complexos Mycobacterium tuberculosis e Mycobacterium avium. A análise estatística foi realizada para comparar os resultados de teste de tuberculina, padrão ouro para o diagnóstico in vivo da bTB, com PCR em tempo real, determinando-se assim a especificidade e sensibilidade do método molecular. O teste cervical comparativo (TCC) foi realizado em 238 animais, dos quais 193 tiveram DNA dos suabes nasais adequados para análise molecular, como indicado pela amplificação do gene gliceraldeído-3-fosfato-desidrogenase (GAPDH), e foram incluídos no estudo. No total, 25 (10,5%) animais foram reativos no TCC, dos quais nenhum foi positivo no teste molecular. Dos 168 animais negativos no TCC, quatro foram positivos para o complexo M. tuberculosis na PCR em tempo real a partir dos suabes nasais. A comparação destes resultados gerou valores de sensibilidade e especificidade de 0% e 97,6%, respectivamente; além disso, baixos coeficientes de concordância e correlação (-0,029 e -0,049, respectivamente) entre os resultados obtidos com ambos os testes também foram observados. Este estudo mostrou que a PCR em tempo real a partir de suabes nasais não é adequada para o diagnóstico in vivo da tuberculose bovina; portanto, o teste da tuberculina ainda é a melhor opção para este fim.(AU)

Mannitol-negative methicillin-resistant Staphylococcus aureus from nasal swab specimens in Brazil

The isolation of mannitol-negative methicillin-resistant Staphylococcus aureus from nasal swabs is reported. Among the 59 isolates, 9 (15%) isolates were mannitol-negative; all of these isolates were categorized as staphylococcal cassette chromosome mec (SCCmec) type IVa. This report emphasizes that mannitol fermentation on mannitol salt agar should not be used as the sole criterion when screening nasal swab specimens for S. aureus.

Modified CHROMagar Acinetobacter Medium for Direct Detection of Multidrug-Resistant Acinetobacter Strains in Nasal and Rectal Swab Samples

This study aimed to investigate whether CHROMagar Acinetobacter medium (CHROMagar, France) in combination with an antimicrobial supplement (modified CHROMagar Acinetobacter; CHROMagar, France) can be used for detecting and isolating multidrug-resistant Acinetobacter species (MRA) in nasal and rectal surveillance cultures. Nasal and rectal swab samples were collected from patients in an intensive care unit at a teaching hospital. The samples were used to inoculate modified CHROMagar Acinetobacter plates, which were examined after 24 and 48 hr of incubation at 37degrees C. Their susceptibility against the antimicrobial agents meropenem, imipenem, ciprofloxacin, and amikacin was analyzed using the Etest (bioMerieux, France). A total of 406 paired samples (406 nasal swabs and 406 rectal swabs) were obtained from 226 patients, and 120 samples (28 nasal and 28 rectal cultures, 47 nasal cultures only, and 17 rectal cultures only) yielded MRA. Seventy-five MRA isolates (18.5%) were recovered from the 406 nasal samples, and 45 MRA isolates (11.1%) were recovered from the 406 rectal samples. Of the 120 MRA isolates, 3 (2.5%) were detected only after 48 hr of incubation. The use of modified CHROMagar Acinetobacter together with nasal and rectal swabs and 1-day incubation is an effective surveillance tool for detecting MRA colonization.

Modified CHROMagar Acinetobacter Medium for Direct Detection of Multidrug-Resistant Acinetobacter Strains in Nasal and Rectal Swab Samples

This study aimed to investigate whether CHROMagar Acinetobacter medium (CHROMagar, France) in combination with an antimicrobial supplement (modified CHROMagar Acinetobacter; CHROMagar, France) can be used for detecting and isolating multidrug-resistant Acinetobacter species (MRA) in nasal and rectal surveillance cultures. Nasal and rectal swab samples were collected from patients in an intensive care unit at a teaching hospital. The samples were used to inoculate modified CHROMagar Acinetobacter plates, which were examined after 24 and 48 hr of incubation at 37degrees C. Their susceptibility against the antimicrobial agents meropenem, imipenem, ciprofloxacin, and amikacin was analyzed using the Etest (bioMerieux, France). A total of 406 paired samples (406 nasal swabs and 406 rectal swabs) were obtained from 226 patients, and 120 samples (28 nasal and 28 rectal cultures, 47 nasal cultures only, and 17 rectal cultures only) yielded MRA. Seventy-five MRA isolates (18.5%) were recovered from the 406 nasal samples, and 45 MRA isolates (11.1%) were recovered from the 406 rectal samples. Of the 120 MRA isolates, 3 (2.5%) were detected only after 48 hr of incubation. The use of modified CHROMagar Acinetobacter together with nasal and rectal swabs and 1-day incubation is an effective surveillance tool for detecting MRA colonization.

Detection of mycobacterium bovis DNA in nasal swabs from tuberculous cattle by a multiplex PCR

Detection of tuberculosis in cattle relies on the intradermal tuberculin test (ITT), but a definitive diagnosis requires identification of the pathogen after the animal is slaughtered. DNA in nasal swabs from 50 cows was analyzed by m-PCR, targeting for the RvD1-Rv2031c and IS6110 sequences. M. bovis was identified in two of 34 tuberculous cows (5.9 percent). The use of mPCR of nasal swabs as an in vivo diagnostic tool for bovine tuberculosis is suggested.

Monitoring of Methicillin-resistant Staphylococcus aureus in Nasal Swabs Obtained from Dental Clinic Healthcare Providers and Medical Environment Nurses

The aims of this study were to investigate the nosocomial infection route of methicillin-resistant Staphylococcus aureus (MRSA) and explore preventative methods for this pathogen that involve blocking its dispersion. We cultured MRSA from nasal cavity swabs collected between June and July 2008 that we obtained from eight dental healthcare providers, 32 nurses and the sputum specimens of two patients from our hospital. In addition, we used VITEK 2 equipment to measure drug sensitivity, and we further performed biochemical testing and pulse-field gel electrophoresis (PFGE) to isolate MRSA colonies. The incidence of these bacteria on the nasal swabs was 25.0% from dental clinic healthcare providers, 13.6% from the internal medicine ward nurses and 30.0% from intensive care unit nurses. Moreover, MRSA was detectable in sputum specimens of ward patients. The antimicrobial agents resistance and partial PFGE types of MRSA showed a similar pattern. We suggest from these analyses that nasal cavity infection by MRSA could occur by cross contamination between healthcare providers and patients which underscores the importance of stringent MRSA management practices.