Determination of Viable Allergenic Fungi in the Documents Repository Environment of the National Archive of Cuba

Research Article

Austin J Public Health Epidemiol. 2018; 5(3): 1077.

Determination of Viable Allergenic Fungi in the Documents Repository Environment of the National Archive of Cuba

Borrego SF* and Molina A

Preventive Conservation Laboratory. National Archive of the Republic of Cuba, Cuba

*Corresponding author: Borrego SF, Preventive Conservation Laboratory, National Archive of the Republic of Cuba, Compostela No. 906 esq. a San Isidro, PO Box: 10100, Habana Vieja, Havana, Cuba

Received: September 05, 2018; Accepted: September 26, 2018; Published: October 03, 2018


Introduction: Intense exposure to airborne fungal propagules has been associated with the appearance of allergic diseases and mycoses. Indoor environments of archives and libraries are a reservoir of fungal propagules due mainly to abundance of dust, the heterogeneous nature of substrates and overcrowded conditions in repositories, which constitute complex ecosystems. Besides, these environments in tropical countries can be dangerous not only to preserve documents but also for health because having high temperatures and relative humidity.

Objective: The aim of this work was to evaluate the degree of air pollution with allergenic fungi viable in a repository with documents that are manipulated with high frequency (work environment).

Methodology: Air sampling was performed by two methods: active (biocollector) and passive (sedimentation plate). In all cases Petri dishes with Malta Extract Agar supplemented by NaCl (7.5%) was used to isolate the environmental fungi. Fungi were taxonomically identified, and spores were measured to determine their penetrability in the human respiratory tract, and its impact on episodes of allergy.

Results: In terms of concentration and diversity, the repository environment behaved as a fungal propagules reservoir, which showed that there is significant health risk for the staff that manipulates the documents. Some spores were shown to be able to reach the lower respiratory tract when inhaled, which increases their allergenic and pathogenic potential. Aspergillus, Cladosporium, Penicillium and Alternaria, which are referred to as highly allergenic fungi, were prevalent.

Conclusion: Aerobiological studies are a valuable tool for the treatment of persons with allergy to fungi and other disorders that they produce.

Keywords: Anemophilous fungi; Occupational diseases; Allergies; Health; Documentary repository; Archives environments


The microbiological quality of indoor air has been related to the appearance of occupational diseases since in certain work environments exposure to biological agents can be intense and persistent [1,2]. The fungal extensive growth has most often been associated with the presence of water in materials or condensation from high humidity, but the environment does not have to be “wet” to support mold associated with health problems. Dampness, which is noted only by minor moisture/condensate, is adequate for some mold, including species of Aspergillus and Penicillium, molds that are thought to be a problem to the health of some building occupants. Other, more hydrophilic molds (Stachybotrys, Fusarium and Acremonium) grow in higher moisture content [2]. For these reason, this phenomenon is increased in areas of tropical climate and buildings with inefficient ventilation or air conditioning systems. Numerous studies have established a close relationship between environmental conditions, the presence of anemophilous fungi and its incidence in the unleashing of respiratory diseases and allergic [3-6]. It is proposed that of 753 allergens officially recognized by the World Organization of Health (WHO) the 16% is of fungal origin and there is sensitization to almost 80 genera [6]. The groups with the highest incidence in type I allergic reactions are the ascomycetes and basidiomycetes [4,7]. In the indoor environments its presence is associated with other pathologies infections (mycosis) mediated by diverse virulence factors that vary according to the groups or taxones [4,7-11].

Allergic responses to fungi are more directly related to the spore than to other fungal propagules, such as mycelium fragments, volatile organic compounds or mycotoxins associated with them. Spores produce allergic reactions due to proteins or glycoproteins that are found on your wall. The answers to each type of spores differ according to the individual, the population and present great variability in their severity [12].

The possibility that a person inhales spores, both in outdoor such as indoor environments, it is elevated, which depends to a large extent on their environmental concentration and physical size [13]. Indoor environments of archives and libraries are a reservoir of fungal propagules due mainly to abundance of dust, the heterogeneous nature of substrates and overcrowded conditions in repositories, which constitute complex ecosystems [14-19].

For this reason, the need to perform quantitative and qualitative follow-up studies and characterization of airborne mycobiota in this type of ecosystem, which will contribute to the improvement of the quality of life of the personnel that works in these institutions or receives systematic services in them.

In Cuba there are few studies of this nature even when the weather conditions are favorable for the development and dispersal of fungi and there is an important sensitization to their spores in the population [20]. The repositories of the National Archive of the Republic of Cuba (NARC) hoard documentation of cultural, historical and scientific interest that hundreds of users request daily. This entails that archivists, stationary and the rest of the personnel involved in the service are exposed to a significant number of fungal allergens for long periods of time (workdays).

The aim of this research was to evaluate the degree of air pollution with allergenic fungi viable in a repository with documents that are manipulated with high frequency (work environment).

Materials and Methods

Characteristics of the study deposit and points of sampling

The study was conducted in a repository that protects a much reviewed documents in the NARC. This archive is located in the municipality of Habana Vieja, Havana, Cuba, in an area bordering the port of Havana, characterized by significant levels of pollution of air, as consequence of the industrial activity and movement vehicular. The repository studied is located in the second floor of building and its dimensions are (length x width x height) 15.2 x 6.2 x 2.5 m; it has natural cross-ventilation system through holes in the wall designed especially for that purpose. The repository store treasures documents on paper of high scientific value and historical heritage, sheltered in wood bookshelf. The access to the premises by the staff and the manipulation of these materials is very frequent due to the high number of documents requested by the users.

Measurements of temperature and relative humidity

Although data is collected continuously using a thermo hygrograph, measurements were made during the collection of samples at each point of sampling using a digital thermo-hygrometer Pen TH 8709 (China).

Microbiological sampling of the air

Seven air sampling points were established agreement with Sánchis [21]. In addition, according to Pasquarella [19], a sample of outdoor air was obtained as a control.

The air samples were taken by two methods: one active (indoor and outdoor) and another passive (indoor). For the plate sedimentation method (passive) suggested by Omeliansky [22-25] open Petri dishes were placed of 110 mm in diameter for 5 minutes at 1.5m from floor. With the volumetric method (active) a SAS Super 100TM biocollector (VWR International Srl, Italy) was used for 1 min at 100 L/min to a similar height to the above mentioned.

In both cases the culture medium used was Malta Extract Agar (MEA) supplemented with Sodium Chloride (NaCl) (7.5%) [26] facilitates the growth of halophilic fungi and some xerophilic species; also, it is used to limit the colonies growth of Mucorales. After the samplings, the dishes were incubated inverted for 7 days at 30°C; then the counting and isolation of different colonies was made for later analyzes.

Biometric analysis

The colony forming units per cubic meter of air (UFC/m3) were determined for each of the sampling methods:

1. Passive method, according to the equation described by Omeliansky [22-25]:

Where: N, microbial concentration in UFC/m3; a, number of colonies per Petri dish; b, area of the Petri dish (cm2); t, exposure time (minute)

2. Active method, according to the manufacturer’s instructions of the team [27]:

The Relative Density (RD) of each taxon from the formula proposed by Smith [28]:

RD = (number of colonies of one taxon / total number of colonies) x 100

Student’s t test was used to evaluate differences in the fungal concentrations obtained by both methods.

Taxonomic identification of the isolates

For the identification the characteristics were taken into account cultural and morphological characteristics of the colonies and of the structures by observation to the stereomicroscope and under an optical microscope, depending on convenient. These characteristics were determined from colonies of each isolate obtained by inoculation in the MEA medium. For observation of the morphological characteristics microcultures were mounted according to the technique of Li et al. [29], as well as fresh, semi-permanent preparations with lactophenol. For the observation of structures hyalines were used lactophenolcotton blue [30] or lactophenol-fushina [31].

The observations and measurements were made in a field trinocular biological microscope clear with digital camera coupled.

Taxonomic identification up to the level of gender was performed according to the criteria of Kendrick and Carmichael [32] and Barnett and Hunter [33]. The identification of Aspergillus species were performed according to Raper and Fennel [34]. To identify up species of the isolates of the genus Cladosporium, performed microcultures in MEA media, agar dextrose potato and synthetic nutrient agar; they had consider the criteria of Castañeda [35] and Bensch [36].

In all cases, at least 20 observations were made distributed in several fields of vision, in preparations of both the young part and the mature area of the colony. Measurements of size conidial of each of the strains were taken into account for the analysis of the penetration of conidia in the human respiratory tract.

Results and Discussion

Concentration of fungi in the air of the repository

In order to carry out a more complete study from a qualitative point of view it was complemented an active method of aerial sampling with another passive, which implied differences between the concentrations estimated from each of them, even in the same sampling point. These differences have been informed by several authors [19,37,38], but this passive method was accepted in environments study by Abdel-Hameed, and Abdel-Mawla [22] and Abdel Hameed et al. [24] and used by different authors previously [23,25,26,39,40].

The determination of concentrations of fungal propagules in the repository allowed to estimate general form the level of air pollution by fungi viable (Table 1).