Atypical bacterial co-infections among patients with COVID-19: A study from India.

Emerging evidence shows co-infection with atypical bacteria in coronavirus disease 2019 (COVID-19) patients. Respiratory illness caused by atypical bacteria such as Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila may show overlapping manifestations and imaging features with COVID-19 causing clinical and laboratory diagnostic issues. We conducted a prospective study to identify co-infections with SARS-CoV-2 and atypical bacteria in an Indian tertiary hospital. From June 2020 to January 2021, a total of 194 patients with laboratory-confirmed COVID-19 were also tested for atypical bacterial pathogens. For diagnosing M. pneumoniae, a real-time polymerase chain reaction (PCR) assay and serology (IgM ELISA) were performed. C. pneumoniae diagnosis was made based on IgM serology. L. pneumophila diagnosis was based on PCR or urinary antigen testing. Clinical and epidemiological features of SARS-CoV-2 and atypical bacteria-positive and -negative patient groups were compared. Of the 194 patients admitted with COVID-19, 17 (8.8%) were also diagnosed with M. pneumoniae (n = 10) or C. pneumoniae infection (n = 7). Confusion, headache, and bilateral infiltrate were found more frequently in the SARS CoV-2 and atypical bacteria co-infection group. Patients in the M. pneumoniae or C. pneumoniae co-infection group were more likely to develop ARDS, required ventilatory support, had a longer hospital length of stay, and higher fatality rate compared to patients with only SARS-CoV-2. Our report highlights co-infection with bacteria causing atypical pneumonia should be considered in patients with SARS-CoV-2 depending on the clinical context. Timely identification of co-existing pathogens can provide pathogen-targeted treatment and prevent fatal outcomes of patients infected with SARS-CoV-2 during the current pandemic.

Investigation on Atypical Pathogens related with Community Acquired Pneumonia and the Factors Associated with Mycoplasma Pneumoniae Infection in Jiangsu, China.

BACKGROUND: Community acquired pneumonia remains a leading infectious cause of hospitalization with substantial morbidity and mortality in China. At present, the role of atypical pathogens in CAP arouses peoples' concern. Previous studies indicated that MP was the dominant pathogen of CAP, but the associated factors of MP infection were rarely reported. METHODS: We retrospectively investigated the distribution of atypical pathogens related with CAP and compared their differences among various populations. Furthermore, we accessed the associated factors of MP infection in various population. RESULTS: A total of 3,675 patients were enrolled and divided into three groups. One thousand and eighty-nine subjects (29.6%) were infected with at least one atypical pathogen. MP was the most predominant pathogen in these CAP patients. Our study found that infection rates of the atypical pathogens were significantly different among three groups. Our results also revealed, in a pediatric group, as the temperature increased, so did the infection rate of MP, while it was the opposite in adult and elderly groups. Furthermore, in preschool and school-age children, high temperature, female, PIVs, ADV, and INFB infection were independent risk factors for MP infection, INFA infection was a protection factor for MP infection. However, in adult and elderly groups, the associated factors might be different. CONCLUSIONS: The infection of atypical pathogens related with CAP is quite serious, and MP infection plays a key role in CAP. Besides, the infection rates of the atypical pathogens are different in various populations, as are the associated factors for MP infection.

Acute Deep Infections of the Upper Extremity: The Utility of Obtaining Atypical Cultures in the Presence of Purulence.

PURPOSE: In the setting of acute deep upper extremity infections, evidence is lacking to guide the decision whether to send atypical cultures (fungal and acid-fast-bacillus [AFB]) during surgical debridement, especially in the presence of purulent fluid that is commonly observed with typical bacterial infections. Our purpose was to determine the frequency of positive atypical cultures and the frequency with which they alter treatment, and identify factors associated with positive atypical cultures. METHODS: We retrospectively identified 100 adult patients undergoing surgical debridement of acute deep infections of the upper extremity in which fungal and/or AFB cultures were sent. Necrotizing and superficial infections were excluded. Descriptive statistics were used to describe patient characteristics, infection diagnoses, number of cultures sent with corresponding rates of positivity, and treatments. Cohorts with positive and negative atypical cultures were compared with bivariate analysis for all collected variables. RESULTS: One or more immunocompromising comorbidities were present in 46% of patients. Diagnoses included soft tissue abscess (46%), suppurative flexor tenosynovitis (22%), septic arthritis (21%), osteomyelitis (9%), and septic bursitis (2%). Aerobic bacterial, anaerobic bacterial, fungal, and AFB cultures were sent in 100%, 99%, 94%, and 82% of patients, respectively. Corresponding rates of positivity were 74%, 34.3%, 5.3%, and 2.4%, respectively. Atypical cultures were positive for 7% of patients and 2.9% of all atypical tests sent. Antibiotic treatment was influenced by atypical culture data for 4% of patients. For patients with positive atypical cultures, purulence was observed during surgery in 86% of cases. Bivariate analysis demonstrated symptom duration greater than 7 days as potentially associated with atypical culture positivity. CONCLUSIONS: Intraoperative purulence at the time of surgical intervention should not deter the surgeon from obtaining atypical cultures. As expected, atypical cultures are infrequently positive given the rarity of associated diseases. Symptoms greater than 7 days may predict a higher incidence of atypical culture positivity for patients being treated surgically within 30 days of initial symptom onset. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Antisuero AA479: nuevo reactivo para la serotipificación de variantes atípicas se Shigella flexneri / AA479 antiserum: new reagent for the serotype characterization of atypical variants of Shigella flexneri

Shigella flexneri is divided into 13 serotypes based on the combination of antigenic determinants present in the O-antigen. A new O-antigen modification with phosphoethanolamine has been identified. The presence of this antigenic determinant (called E1037) is recognized by monoclonal antibody MASF IV-1. Given the increasing incidence of these new variants and the difficulty in supplying the monoclonal antibody to our country, we produced a polyclonal antiserum (AA479) through immunization with a S. flexneri Xv strain. The antiserum specificity was assessed by slide agglutination against isolates from clinical cases and a culture collection representing all Shigella serotypes. The results obtained demonstrated a 100% correlation between AA479 absorbed antiserum and monoclonal antibody MASF IV-1. The availability of AA479 antiserum in every public hospital in Argentina will allow us to identify atypical S. flexneri isolates in order to strengthen Shigella surveillance in our country and to compare with global epidemiological dat

Shigella flexneri se divide en al menos 13 serotipos sobre la base de la combinación de determinantes antigénicos presentes en el antígeno O. Se identificó una nueva modificación del antígeno O con fosfoetanolamina. La presencia de este determinante antigénico (denominado E1037) es reconocida por el anticuerpo monoclonal MASF IV-1. Teniendo en cuenta la incidencia creciente de estas nuevas variantes y la dificultad en la provisión del anticuerpo monoclonal para nuestro país, se elaboró un antisuero de tipo policlonal (AA479) mediante la inmunización con un cultivo de S. flexneri Xv. La especificidad del antisuero se evaluó por aglutinación en lámina con aislamientos clínicos y cultivos de colección, con lo que quedaron representados todos los serotipos de Shigella. Los resultados obtenidos demostraron una correlación del 100% entre el antisuero AA479 absorbido y el anticuerpo monoclonal MASF IV-1. La disponibilidad del antisuero AA479 en todos los hospitales públicos de Argentina permitirá identificar los aislamientos atípicos de S. flexneri; de esta forma se podrá fortalecer la vigilancia de Shigella en nuestro país y comparar con los datos epidemiológicos a nivel global

Respiratory viruses and atypical bacteria triggering severe asthma exacerbation in children.

1. Respiratory viruses and atypical bacteria were detected in 51.0% of Hong Kong children with asthma exacerbations, which was significantly higher than the detection rate of 27.3% in children with chronic stable asthma. 2. Co-infections of two or more respiratory pathogens were more commonly found in children with asthma exacerbations (10.7%) than in patients with stable asthma (2.6%). 3. Human rhinovirus infection was a significant risk factor for asthma exacerbations. 4. There was no significant association between the severity of asthma exacerbations and respiratory viral or atypical bacterial infections. 5. Routine use of macrolide antibiotics in the treatment of childhood asthma exacerbations should be discouraged.

Epidemiology of respiratory infections caused by atypical bacteria in two Kenyan refugee camps.

Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella spp. are common causes of atypical pneumonia; however, data about these atypical pathogens are limited in the refugee setting. Paired nasopharyngeal and oropharyngeal specimens were collected from patients with respiratory illness presenting to healthcare centers in two refugee camps in Kenya. The specimens were tested for C. pneumoniae, M. pneumoniae, and Legionella spp. as well as eight respiratory viruses. Atypical pathogens were detected in 5.5% of the specimens of which 54% were co-infected with at least one of the eight viruses tested. Patients positive for atypical bacteria co-infected with virus were significantly more likely to have severe acute respiratory illness than patients infected with only atypical bacteria (P = 0.04). While the percentage of atypical pathogens identified was lower than expected, we found a significant relationship between atypical bacterial-viral co-infection and severity of disease in this refugee population.

[The immunological and molecular diagnostics of respiratory tract infections]. / Diagnostyka immunologiczna i molekularnazakazen dróg oddechowych.

Diagnostic strategies in upper and lower respiratory tract infections include conventional procedures and the new molecular tools. Serology plays a role in certain viral and atypical infections of lower respiratory track but is not reliable in small children and in immunocompromised subjects. Antigen detection can be also carried out. If a potential pathogen is non detectable by simply assay or in severe or complicated lower respiratory tract infections, the use of molecular tools is highly indicated.

Role of respiratory pathogens in infants hospitalized for a first episode of wheezing and their impact on recurrences.

In order to evaluate the infectious agents associated with the first episode of severe acute wheezing in otherwise healthy infants and to define the role of each of them in recurrences, 85 patients in Italy, aged <12 months, hospitalized because of a first acute episode of wheezing, were prospectively enrolled between 1 October 2005 and 31 March 2006. Upon enrollment, nasopharyngeal swabs were collected for the real-time PCR detection of respiratory syncytial virus (RSV) types A and B, influenza virus types A and B, adenovirus, parainfluenza viruses types 1, 2, 3 and 4, rhinovirus, human metapneumovirus, human coronavirus types 229E, OC43, NL63, and HKU1, bocavirus, enterovirus, and paraechovirus; nasopharyngeal aspirates were also obtained to detect atypical bacteria. At least one infectious agent was identified in 76 children (89.4%). RSV was the most frequently detected pathogen and its prevalence was significantly higher than that of the other pathogens in both age groups, and significantly higher in the children aged 3-12 months than in those aged <3 months. Only the children with RSV infection experienced recurrent wheezing. Viral load was significantly higher in children with than in those without recurrent wheezing. This study shows that RSV is the main reason for hospitalization during the first wheezing episode in infants, and that it appears to be the only pathogen associated with a high frequency of recurrences. A high viral load seems to be strictly related to the likelihood of recurrence.

[Atypical bacteria in respiratory tract infections --pathogenesis and diagnosis]. / Bakterie atypowe w zakazeniach dróg oddechowych--patogeneza i diagnostyka.

Atypical bacteria, including Mycoplasma pneumoniae, Chlamydophila pneumonia and Legionella pneumophila play significant role in respiratory tract infections and account for 40% of all cases of community acquired pneumonia (CAP). These organisms also commonly occur as co-pathogens in mixed infections with mortality rates as high as 25%. The biological mechanisms and diagnosis of atypical infections is presented in this study.

[Upper respiratory tract infections in children caused by atypical bacteria]. / Zakazenia górnych dróg oddechowych u dzieci wywolane przez bakterie atypowe.

UNLABELLED: It encounters despite solid progress in development of diagnostic methods diagnostics the diseases of upper respiratory tract and ears in children called out by atypical bacteria's on the ground clinical symptoms and their treatment is difficulty still. AIM: The performance of accessible review of current literature was on the aim of work opinion of the atypical bacteria's part in evocation the infections the upper respiratory tract and ears in children, and performance of characteristic symptoms of clinical diseases these organs the bacteria's also. CONCLUSIONS: The quoted in work results of investigations do not it let on the unambiguous opinion the atypical bacteria part in contagions of infections the upper respiratory tract and ears in children. It seems however, that Mycoplasma pneumoniae answers first of all for evocation the acute infections of upper respiratory tract; however Chlamydophila pneumoniae plays the larger part in illnesses chronic as well as co-existent pathogen in illnesses sharp. Atypical bacteria can cause upper respiratory tract infections significantly more often than previously thought. These infections often occur in patients with history of respiratory recurrences.

[Upper respiratory tract infection in adults caused by atypical bacteria]. / Zakazenia górnych dróg oddechowych u doroslych wywolane przez bakterie atypowe.

Atypical bacteria play role in infection of upper respiratory tract in adults. The most often bacteria playing role in these infections are Chlamydophila pneumioniae and Mycoplasma pneumoniae. These bacteria have significant impact in pharyngitis and tonsillitis and less in rhinosinusitis. Atypical bacteria can cause infection of the upper respiratory tract as a single pathogen or one of the pathogens. Mycoplasma pneumoniae most often is s a single causal factor of the disease, when Chlamydophila pneumoniae most often co-exists with infection with other pathogens. Majority of infections of upper respiratory tract in adults caused by atypical bacteria has mild history with insignificant sings and symptoms. Suspicion of the disease can be recurrent history of disease or absence of recovery after standard treatment.

Multiplexed serology in atypical bacterial pneumonia.

Atypical pneumonia is a term applied to lower respiratory tract infections that are not characterized by signs and symptoms of lobar consolidation. This article will discuss the epidemiology, clinical manifestations, and laboratory diagnoses of Mycoplasma pneumoniae, Chlamydia sp., Legionella sp., Francisella tularensis, and Coxiella burnetii, which are the agents most commonly associated with atypical pneumonia. Because many of these pathogens are intracellular, diagnosis depends upon serological confirmation. The current serological tests used to identify these agents in the etiologic diagnosis of atypical pneumonia are described. Recently, however, it has become possible to make a diagnosis directly in these cases using DNA or protein microarrays. Here, we describe the development of a new, automated technique for simultaneous testing and detection of several pathogens using a multiplexed serology test. This should prove to be a valuable tool for the rapid determination of patient status, allowing effective and efficient postexposure prophylaxis and treatment.

Viral and atypical bacterial infections in the outpatient pediatric cystic fibrosis clinic.

BACKGROUND: Respiratory viral and atypical bacterial infections are associated with pulmonary exacerbations and hospitalisations in cystic fibrosis patients. We wanted to study the impact of such infections on children attending the outpatient clinic. METHODS: Seventy-five children were followed for 12 months at regular clinic visits. Routine sputum/laryngeal aspirations were tested with PCR for 7 respiratory viruses. Antibodies against C. pneumoniae, M. pneumoniae and B. pertussis were measured every 3-4 months. FEV-1, FEF(25-75) and specific airway resistance, "viral" symptoms and bacterial culture were recorded. RESULTS: Ninety-seven viral and 21 atypical bacterial infections were found. FEV-1 was significantly reduced during viral infection (-12.5%, p=0.048), with the exception of rhinovirus infection. A small change in FEV-1 (-3%) was seen during atypical bacterial infection (p=0.039). Viral and atypical bacterial infections caused no change in type and frequency of bacterial culture. Positive predictive value of "viral symptoms" was low (0.64%). Eight patients received "unnecessary" antibiotics because of viral symptoms. CONCLUSIONS: Some viral infections and atypical bacterial infections affect FEV-1 acutely. Viral infections did not precipitate bacterial infection or change of colonisation. Clinical symptoms failed to diagnose viral infection accurately. Routine surveillance for virus or atypical bacteria seems not to be justified in this patient category.

Alpha-proteobacteria cultivated from marine sponges display branching rod morphology.

Most isolates recovered from marine environments are Gram-negative proteobacteria, even with the use of various media and media additions to enhance recoverability. Cultivation studies with two genera of deep-water sponges yielded nine isolates that demonstrated bulbous branching rod morphology, which is usually associated with microorganisms staining Gram-positive. Gram reactions indicated that the isolates were Gram-negative, which was confirmed by partial 16S rDNA sequencing. All nine isolates were shown to be alpha-proteobacteria most closely related to other alpha-proteobacteria isolated from various sponges.

Atypical pathogens in community-acquired pneumonia.

The atypical pathogens are an important and significant cause of CAP. The clinical and radiologic manifestations of CAP caused by these pathogens are modulated by the immunologic and physiologic status of the host, and therefore are not pathogen-specific. The range of frequencies found in various studies for the atypical pathogens among the causes of CAP is broad. These frequencies are affected by very important factors that should be recognized. In a significant percentage of patients, an atypical pathogen can be identified together with an additional cause. The significance of multiple causes has not been clarified sufficiently. The principal diagnostic techniques in use today for the causative diagnosis of CAP are serologic tests. Different serologic methods have been used in various studies and diagnostic criteria are not standardized. In the future it is likely that diagnostic testing will be based on the PCR technique on serum samples. The effectiveness and importance of antimicrobial therapy in some patients with atypical pathogen CAP are unclear. The accepted therapy today for atypical pathogen CAP, which is based on erythromycin, will probably be changed in the near future in favor of the new generations of fluoroquinolone or the new macrolide preparations.

Identification of atypical strains of Staphylococcus epidermidis by use of molecular tools.

Four atypical coagulase-negative staphylococcal (CNS) isolates from clinical sources were compared with Staphylococcus epidermidis strains by ribotyping. The ribotypes of the four strains shared close rDNA restriction profiles with those of the S. epidermidis strains used. The DNA sequence encoding 16S rRNA demonstrated 99.9% homology with S. epidermidis. S1 nuclease experiments showed that these atypical strains formed a homogeneous genomic group. DNA-DNA homologies between the S. epidermidis type strain CCM 2124 and the four CNS isolates ranged from 70 to 89%. The guanine-plus-cytosine content of the deoxyribonucleic acid of the four strains ranged from 31 to 32 mol%.

Appropriateness of laboratory tests: requests for atypical pneumonia serology in a teaching hospital.

The cost of providing medical care is ever-increasing but the resources available are at best static. Major savings can be made by reducing inappropriate investigations. Using serological testing for organisms causing atypical pneumonia as an example, we examined the appropriateness of requests and also physicians' understanding of the test. Of 119 patients tested, only 3 had titres indicative of acute infection. Most patients were tested within 2 days of hospital admission, before receipt of results excluding more likely diagnoses. Forty-five patients had no current or recent respiratory symptoms, in whom infection was highly unlikely. Titres were most often requested by the least experienced members of the clinical team. Of 70 patients with an acute illness in whom a definitive diagnosis, bacteriological or otherwise, was not made, in only 9 was a convalescent specimen sent for follow-up titres. Most requests for serology for organisms causing atypical pneumonia were inappropriate. Furthermore, in the majority of cases the test was incorrectly used.

[The aerobic intestinal flora of the microchiropteran bat Chaerephon pumila in Madagascar]. / Etude de la flore intestinale aérobie de microchéiroptéres Chaerephon pumila à Madagascar.

From stools of 88 malagasy insect eater bats Chaerephon pumila, a large amount of bacterial strains were isolated. Twenty different species were recognized, most of them belonged to Enterobacteriaceae family. Eight strains were identified as Salmonella enterica subsp. enterica O48: -; 1.5, despite many atypical characters. Strains of Salmonella enteritidis, Koserella trabulsii, Kluyvera sp., ODC negative Serratia marcescens, atypical Hafnia alvei... were also identified.